difference between global warming and climate change essay

What's the difference between global warming and climate change?

Global warming refers only to the Earth’s rising surface temperature, while climate change includes warming and the “side effects” of warming—like melting glaciers, heavier rainstorms, or more frequent drought. Said another way, global warming is one symptom of the much larger problem of human-caused climate change.

Global warming is just one symptom of the much larger problem of climate change. NOAA Climate.gov cartoon by Emily Greenhalgh.

Another distinction between global warming and climate change is that when scientists or public leaders talk about global warming these days, they almost always mean human -caused warming—warming due to the rapid increase in carbon dioxide and other greenhouse gases from people burning coal, oil, and gas.

Climate change, on the other hand, can mean human-caused changes or natural ones, such as ice ages. Besides burning fossil fuels, humans can cause climate changes by emitting aerosol pollution—the tiny particles that reflect sunlight and cool the climate— into the atmosphere, or by transforming the Earth's landscape, for instance, from carbon-storing forests to farmland.

A climate change unlike any other

The planet has experienced climate change before: the Earth’s average temperature has fluctuated throughout the planet’s 4.54 billion-year history. The planet has experienced long cold periods ("ice ages") and warm periods ("interglacials") on 100,000-year cycles for at least the last million years.

Previous warming episodes were triggered by small increases in how much sunlight reached Earth’s surface and then amplified by large releases of carbon dioxide from the oceans as they warmed (like the fizz escaping from a warm soda).

Increases and decreases in global temperature during the naturally occurring ice ages of the past 800,000 years, ending with the early twentieth century. NOAA Climate.gov graph by Fiona Martin, based on EPICA Dome C ice core data provided by the Paleoclimatology Program at NOAA’s National Centers for Environmental Information.

Today’s global warming is overwhelmingly due to the increase in heat-trapping gases that humans are adding to the atmosphere by burning fossil fuels. In fact, over the last five decades, natural factors (solar forcing and volcanoes) would actually have led to a slight cooling of Earth’s surface temperature.

Global warming is also different from past warming in its rate. The current increase in global average temperature appears to be occurring much faster than at any point since modern civilization and agriculture developed in the past 11,000 years or so—and probably faster than any interglacial warm periods over the last million years.

Temperatures over most of the past 2000 years compared to the 1961-1990 average, based on proxy data (tree rings, ice cores, corals) and modern thermometer-based data. Over the past two millenia, climate warmed and cooled, but no previous warming episodes appear to have been as large and abrupt as recent global warming. NOAA Climate.gov graph by Fiona Martin, adapted from Figure 34.5 in the National Climate Assessment, based on data from Mann et al., 2008.

New understanding required new terms

Regardless of whether you say that climate change is all the side effects of global warming, or that global warming is one symptom of human-caused climate change, you’re essentially talking about the same basic phenomenon: the build up of excess heat energy in the Earth system.  So why do we have two ways of describing what is basically the same thing?

According to historian Spencer Weart , the use of more than one term to describe different aspects of the same phenomenon tracks the progress of scientists’ understanding of the problem.

As far back as the late 1800s, scientists were hypothesizing that industrialization, driven by the burning of fossil fuels for energy, had the potential to modify the climate. For many decades, though, they weren’t sure whether cooling (due to reflection of sunlight from pollution) or warming (due to greenhouse gases) would dominate.

By the mid-1970s, however, more and more evidence suggested warming would dominate and that it would be unlike any previous, naturally triggered warming episode. The phrase “global warming” emerged to describe that scientific consensus.

Change in temperature (degrees per century) from 1900-2014. Gray areas indicate where there is insufficient data to detect a long-term trend. NOAA Climate.gov map, based on NOAAGlobalTemp data from NOAA's National Centers for Environmental Information.

But over subsequent decades, scientists became more aware that global warming was not the only impact of excess heat absorbed by greenhouse gases.  Other changes—sea level rise, intensification of the water cycle, stress on plants and animals—were likely to be far more important to our daily lives and economies. By the 1990s, scientists increasingly used “human-caused climate change” to describe the challenge facing the planet.

The bottom line

Today’s global warming is an unprecedented type of climate change, and it is driving a cascade of side effects in our climate system. It’s these side effects, such as changes in sea level along heavily populated coastlines and the worldwide retreat of mountain glaciers that millions of people depend on for drinking water and agriculture, that are likely to have a much greater impact on society than temperature change alone.

Broecker, W. S. (1975). Climatic Change: Are We on the Brink of a Pronounced Global Warming? Science , 189(4201), 460–463.   http://doi.org/10.1126/science.189.4201.460

Climate Data Primer . Climate.gov.

Gillett, N. P., V. K. Arora, G. M. Flato, J. F. Scinocca, and K. von Salzen, 2012: Improved constraints on 21st-century warming derived using 160 years of temperature observations. Geophysical Research Letters, 39, 5, doi:10.1029/2011GL050226. [Available online at http://onlinelibrary.wiley.com/doi/10.1029/2011GL050226/pdf ]

Global Warming FAQ . Climate.gov.

How do we know the world has warmed? by J. J. Kennedy, P. W. Thorne, T. C. Peterson, R. A. Ruedy, P. A. Stott, D. E. Parker, S. A. Good, H. A. Titchner, and K. M. Willett, 2010: [in " State of the Climate in 2009 "]. Bull. Amer. Meteor. Soc., 91 (7), S79-106.

Huber, M., and R. Knutti, 2012: Anthropogenic and natural warming inferred from changes in Earth’s energy balance. Nature Geoscience, 5, 31-36, doi:10.1038/ngeo1327. [Available online at http://www.nature.com/ngeo/journal/v5/n1/pdf/ngeo1327.pdf ]

Jouzel, J., et al.  2007. EPICA Dome C Ice Core 800KYr Deuterium Data and Temperature Estimates.   IGBP PAGES/World Data Center for Paleoclimatology  Data Contribution Series # 2007-091. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA.

Mann, M. E., Zhang, Z., Hughes, M. K., Bradley, R. S., Miller, S. K., Rutherford, S., & Ni, F., 2008: Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia. Proceedings of the National Academy of Sciences, 105(36), 13252-13257. doi: 10.1073/pnas.0805721105.

Melillo, Jerry M., Terese (T.C.) Richmond, and Gary W. Yohe, Eds., 2014: Climate Change Impacts in the United States: The Third National Climate Assessment . U.S. Global Change Research Program, 841 pp. doi:10.7930/J0Z31WJ2. Online at: nca2014.globalchange.gov

National Academy of Sciences, Climate Research Board, Carbon Dioxide and Climate: A Scientific Assessment (Jules Charney, Chair) . (1979). Washington, DC: National Academy of Sciences. [Online (pdf)] http://web.atmos.ucla.edu/~brianpm/download/charney_report.pdf

Walsh, J., D. Wuebbles, K. Hayhoe, J. Kossin, K. Kunkel, G. Stephens, P. Thorne, R. Vose, M. Wehner, J. Willis, D. Anderson, V. Kharin, T. Knutson, F. Landerer, T. Lenton, J. Kennedy, and R. Somerville, 2014: Appendix 4: Frequently Asked Questions. Climate Change Impacts in the United States: The Third National Climate Assessment, J. M. Melillo, Terese (T.C.) Richmond, and G. W. Yohe, Eds., U.S. Global Change Research Program, 790-820. doi:10.7930/J0G15XS3

Weart, S. (2008). Timeline (Milestones). In The Discovery of Global Warming . [Online] American Institute of Physics website.

What's in a Name? Global Warming vs. Climate Change . NASA.

We value your feedback

Help us improve our content

Related Content

News & features, carbon dioxide: earth's hottest topic is just warming up, climate change: atmospheric carbon dioxide, what's the hottest earth's ever been, ocean acidification: the other carbon problem, maps & data, climate forcing, global temperature anomalies - map viewer, sst - sea surface temperature, teaching climate, toolbox for teaching climate & energy, white house climate education and literacy initiative, the smap/globe partnership: citizen scientists measure soil moisture, climate resilience toolkit, food production, food- and water-related threats.

An official website of the United States government

Here's how you know

Official websites use .gov A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

•   Facebook
•   Twitter
•   Linkedin
•   Digg
•   Reddit
•   Pinterest
•   Email

Latest Earthquakes |    Chat Share Social Media  

What is the difference between global warming and climate change?

Although people tend to use these terms interchangeably, global warming is just one aspect of climate change. “Global warming” refers to the rise in global temperatures due mainly to the increasing concentrations of greenhouse gases in the atmosphere. “Climate change” refers to the increasing changes in the measures of climate over a long period of time – including precipitation, temperature, and wind patterns.

Related Content

• Publications

Does the USGS monitor global warming?

Not specifically. Our charge is to understand characteristics of the Earth, especially the Earth's surface, that affect our Nation's land, water, and biological resources. That includes quite a bit of environmental monitoring. Other agencies, especially NOAA and NASA, are specifically funded to monitor global temperature and atmospheric phenomena such as ozone concentrations. The work through...

Will global warming produce more frequent and more intense wildfires?

There isn’t a direct relationship between climate change and fire, but researchers have found strong correlations between warm summer temperatures and large fire years, so there is general consensus that fire occurrence will increase with climate change. Hot, dry conditions, however, do not automatically mean fire—something needs to create the spark and actually start the fire. In some parts of...

What are the long-term effects of climate change?

Scientists have predicted that long-term effects of climate change will include a decrease in sea ice and an increase in permafrost thawing, an increase in heat waves and heavy precipitation, and decreased water resources in semi-arid regions. Below are some of the regional impacts of global change forecast by the Intergovernmental Panel on Climate Change: North America: Decreasing snowpack in the...

How can climate change affect natural disasters?

With increasing global surface temperatures the possibility of more droughts and increased intensity of storms will likely occur. As more water vapor is evaporated into the atmosphere it becomes fuel for more powerful storms to develop. More heat in the atmosphere and warmer ocean surface temperatures can lead to increased wind speeds in tropical storms. Rising sea levels expose higher locations...

How do changes in climate and land use relate to one another?

The link between land use and the climate is complex. First, land cover--as shaped by land use practices--affects the global concentration of greenhouse gases. Second, while land use change is an important driver of climate change, a changing climate can lead to changes in land use and land cover. For example, farmers might shift from their customary crops to crops that will have higher economic...

Why is climate change happening and what are the causes?

There are many “natural” and “anthropogenic” (human-induced) factors that contribute to climate change. Climate change has always happened on Earth, which is clearly seen in the geological record; it is the rapid rate and the magnitude of climate change occurring now that is of great concern worldwide. Greenhouse gases in the atmosphere absorb heat radiation. Human activity has increased...

What are some of the signs of climate change?

• Temperatures are rising world-wide due to greenhouse gases trapping more heat in the atmosphere. • Droughts are becoming longer and more extreme around the world. • Tropical storms becoming more severe due to warmer ocean water temperatures. • As temperatures rise there is less snowpack in mountain ranges and polar areas and the snow melts faster. • Overall, glaciers are melting at a faster rate...

How do we know the climate is changing?

The scientific community is certain that the Earth's climate is changing because of the trends that we see in the instrumented climate record and the changes that have been observed in physical and biological systems. The instrumental record of climate change is derived from thousands of temperature and precipitation recording stations around the world. We have very high confidence in these...

What is carbon sequestration?

Carbon dioxide is the most commonly produced greenhouse gas. Carbon sequestration is the process of capturing and storing atmospheric carbon dioxide. It is one method of reducing the amount of carbon dioxide in the atmosphere with the goal of reducing global climate change. The USGS is conducting assessments on two major types of carbon sequestration: geologic and biologic .

How does carbon get into the atmosphere?

Atmospheric carbon dioxide comes from two primary sources—natural and human activities. Natural sources of carbon dioxide include most animals, which exhale carbon dioxide as a waste product. Human activities that lead to carbon dioxide emissions come primarily from energy production, including burning coal, oil, or natural gas. Learn more: Sources of Greenhouse Gas Emissions (EPA)

How much carbon dioxide does the United States and the World emit each year from energy sources?

The U.S. Energy Information Administration estimates that in 2019, the United States emitted 5,130 million metric tons of energy-related carbon dioxide, while the global emissions of energy-related carbon dioxide totaled 33,621.5 million metric tons.

Two Swimming Polar Bears

Data collected from long distance swims by Polar bears suggest that they do not stop to rest during their journey.

Polar Bear Research, B-Roll 1

Spring 2014. USGS scientists conduct a health evaluation of a young male polar bear in the Arctic as part of the annual southern Beaufort Sea population survey. The bear is sedated for approximately an hour while the team records a variety of measurements and collects key biological samples.

PubTalk 11/2012 — Understanding Climate-Wildlife Relationships

-- are American pikas harbingers of changing conditions?

by USGS Research Ecologist Erik Beever

Tracking Pacific Walrus: Expedition to the Shrinking Chukchi Sea Ice

Summer ice retreat in the Chukchi Sea between Alaska and Russia is a significant climate change impact affecting Pacific Walruses, which are being considered for listing as a threatened species. This twelve minute video follows walruses in their summer sea ice habitat and shows how USGS biologists use satellite radio tags to track their movements and behavior.

PubTalk 3/2010 — Changing Times-- A Changing Planet!

Using phenology to take the pulse of our planet

By Jake F. Weltzin, Executive Director, USA National Phenology Network

USGS Public Lecture Series: Climate Change 101

Climate change is an issue of increasing public concern because of its potential effects on land, water, and biological resources.

The Cold Facts About Melting Glaciers

Most glaciers in Washington and Alaska are dramatically shrinking in response to a warming climate.

Permafrost Erosion Measurement

USGS researcher Benjamin Jones examines a collapsed block of ice-rich permafrost on Barter Island along Alaska's Arctic coast.

Crumbling blocks of permafrost along the Beaufort Coast

USGS integrated drought science

Ecosystem vulnerability to climate change in the southeastern united states, usgs arctic science strategy, landsat surface reflectance data, changing arctic ecosystems: sea ice decline, permafrost thaw, and benefits for geese, remote sensing of land surface phenology, delivering climate science about the nation's fish, wildlife, and ecosystems: the u.s. geological survey national climate change and wildlife science center, the u.s. geological survey climate geo data portal: an integrated broker for climate and geospatial data, changing arctic ecosystems - measuring and forecasting the response of alaska's terrestrial ecosystem to a warming climate, polar bear and walrus response to the rapid decline in arctic sea ice, the concept of geologic carbon sequestration.

No abstract available.

Assessing carbon stocks, carbon sequestration, and greenhouse-gas fluxes in ecosystems of the United States under present conditions and future scenarios

Future temperature and soil moisture may alter location of agricultural regions.

Future high temperature extremes and soil moisture conditions may cause some regions to become more suitable for rainfed, or non-irrigated...

Changes in Rainfall, Temperature Expected to Transform Coastal Wetlands This Century

Changes in rainfall and temperature are predicted to transform wetlands in the Gulf of Mexico and around the world within the century, a new study...

Walrus Sea-Ice Habitats Melting Away

Habitat for the Pacific walrus in the Chukchi Sea is disappearing from beneath them as the warming climate melts away Arctic sea ice in the spring...

Old Growth May Help Protect Northwest Birds from Warming Temperatures

Researchers are working to understand how to lessen the impacts of climate change on birds and other forest inhabitants.

Ancient Permafrost Quickly Transforms to Carbon Dioxide upon Thaw

Researchers from the U.S. Geological Survey and key academic partners have quantified how rapidly ancient permafrost decomposes upon thawing and how...

Scientists Predict Gradual, Prolonged Permafrost Greenhouse Gas Emissions

A new scientific synthesis suggests a gradual, prolonged release of greenhouse gases from permafrost soils in Arctic and sub-Arctic regions, which may...

Rare Insect Found Only in Glacier National Park Imperiled by Melting Glaciers

The persistence of an already rare aquatic insect, the western glacier stonefly, is being imperiled by the loss of glaciers and increased stream...

New Heights of Global Topographic Data Will Aid Climate Change Research

The U.S. Geological Survey announced today that improved global topographic (elevation) data are now publicly available for North and South America...

Water Cycle

• Weather & Climate

Societal Applications

Whats in a name global warming vs. climate change.

The Internet is full of references to global warming . The Union of Concerned Scientists website on climate change is titled "Global Warming," just one of many examples. But we don't use global warming much on this website. We use the less appealing "climate change." Why?

To a scientist, global warming describes the average global surface temperature increase from human emissions of greenhouse gases. Its first use was in a 1975 Science article by geochemist Wallace Broecker of Columbia University's Lamont-Doherty Geological Observatory: "Climatic Change: Are We on the Brink of a Pronounced Global Warming?"1

Broecker's term was a break with tradition. Earlier studies of human impact on climate had called it "inadvertent climate modification."2 This was because while many scientists accepted that human activities could cause climate change, they did not know what the direction of change might be. Industrial emissions of tiny airborne particles called aerosols might cause cooling, while greenhouse gas emissions would cause warming. Which effect would dominate?

For most of the 1970s, nobody knew. So "inadvertent climate modification," while clunky and dull, was an accurate reflection of the state of knowledge.

The first decisive National Academy of Science study of carbon dioxide's impact on climate, published in 1979, abandoned "inadvertent climate modification." Often called the Charney Report for its chairman, Jule Charney of the Massachusetts Institute of Technology in Cambridge, declared: "if carbon dioxide continues to increase, [we find] no reason to doubt that climate changes will result and no reason to believe that these changes will be negligible."3

In place of inadvertent climate modification, Charney adopted Broecker's usage. When referring to surface temperature change, Charney used "global warming." When discussing the many other changes that would be induced by increasing carbon dioxide, Charney used "climate change." Definitions

Global warming: the increase in Earth’s average surface temperature due to rising levels of greenhouse gases.

Climate change: a long-term change in the Earth’s climate, or of a region on Earth.

Within scientific journals, this is still how the two terms are used. Global warming refers to surface temperature increases, while climate change includes global warming and everything else that increasing greenhouse gas amounts will affect.

During the late 1980s one more term entered the lexicon, “global change.” This term encompassed many other kinds of change in addition to climate change. When it was approved in 1989, the U.S. climate research program was embedded as a theme area within the U.S. Global Change Research Program.

But global warming became the dominant popular term in June 1988, when NASA scientist James E. Hansen had testified to Congress about climate, specifically referring to global warming. He said: "global warming has reached a level such that we can ascribe with a high degree of confidence a cause and effect relationship between the greenhouse effect and the observed warming."4 Hansen's testimony was very widely reported in popular and business media, and after that popular use of the term global warming exploded. Global change never gained traction in either the scientific literature or the popular media.

But temperature change itself isn't the most severe effect of changing climate. Changes to precipitation patterns and sea level are likely to have much greater human impact than the higher temperatures alone. For this reason, scientific research on climate change encompasses far more than surface temperature change. So "global climate change" is the more scientifically accurate term. Like the Intergovernmental Panel on Climate Change, we've chosen to emphasize global climate change on this website, and not global warming.

1 Wallace Broecker, "Climatic Change: Are We on the Brink of a Pronounced Global Warming?" Science, vol. 189 (8 August 1975), 460-463.

2 For example, see: MIT, Inadvertent Climate Modification: Report of the Study of Man's Impact on Climate (Cambridge, Mass.: MIT Press, 1971).

3National Academy of Science, Carbon Dioxide and Climate, Washington, D.C., 1979, p. vii.

4U.S. Senate, Committee on Energy and Natural Resources, "Greenhouse Effect and Global Climate Change, part 2" 100th Cong., 1st sess., 23 June 1988, p. 44.

http://www.nasa.gov/topics/earth/features/climate_by_any_other_name.html

What's the difference between global warming and climate change?

• June 23, 2015
• Download Cover Image

Global warming is one symptom of the much larger problem of human-caused climate change.

NOAA funds 11 new projects to remove marine debris

Noaa hurricane hunters play a major role in hurricane forecasting, #harvey is causing catastrophic flooding. get the latest updates, #harvey is drenching texas. get the latest updates, popup call to action.

A prompt with more information on your call to action.

Earth's Changing Climate

Climate change is a long-term shift in global or regional climate patterns. Often climate change refers specifically to the rise in global temperatures from the mid 20th century to present.

Earth Science, Geography, Human Geography, Physical Geography

Loading ...

Climate  is the long-term pattern of weather in a particular area. Weather can change from hour to hour, day to day, month to month or even from year to year. For periods of 30 years or more, however, distinct  weather patterns occur. A  desert  might experience a rainy week, but over the long term, the region receives very little rainfall . It has a dry climate .

Because climates are mostly constant, living things can  adapt  to them. Polar bears have adapted to stay warm in  polar climates , while cacti have evolved to hold onto water in  dry climates . The  enormous  variety of life on Earth results in large part from the variety of climates that exist.

Climates do change, however—they just change very slowly, over hundreds or even thousands of years. As climates change, organisms that live in the area must adapt ,  relocate , or risk going  extinct .

Earth’s Changing Climate Earth’s climate has changed many times. For example,  fossils from the Cretaceous period (144 to 65 million years ago) show that Earth was much warmer than it is today.  Fossilized plants and animals that normally live in warm  environments have been found at much higher  latitudes than they could survive at today. For instance,  breadfruit  trees ( Artocarpus altilis ), now found on  tropical   islands , grew as far north as Greenland.

Earth has also experienced several major  ice ages —at least four in the past 500,000 years. During these periods, Earth’s  temperature   decreased , causing an  expansion  of  ice sheets and  glaciers . The most recent Ice Age began about two million years ago and peaked about 20,000 years ago. The ice caps began retreating 18,000 years ago. They have not disappeared completely, however. Their presence in Antarctica and Greenland suggests Earth is still in a sort of ice age. Many scientists believe we are in an  interglacial period , when warmer temperatures have caused the ice caps to  recede . Many centuries from now, the glaciers may advance again. Climatologists look for evidence of past climate change in many different places. Like clumsy criminals, glaciers leave many clues behind them. They scratch and  scour   rocks as they move. They deposit sediment  known as glacial till. This sediment sometimes forms mounds or ridges called  moraines . Glaciers also form elongated oval hills known as  drumlins . All of these geographic features on land that currently has no glaciers suggest that glaciers were once there. Scientists also have chemical evidence of ice ages from sediments and  sedimentary rocks . Some rocks only form from glacial material. Their presence under the ocean or on land also tells scientists that glaciers were once present in these areas. Scientists also have paleontological evidence—fossils. Fossils show what kinds of animals and plants lived in certain areas. During ice ages, organisms that are adapted to cold weather can increase their range , moving closer to the  Equator . Organisms that are adapted to warm weather may lose part of their  habitat , or even go extinct.

Climate changes occur over shorter periods, as well. For example, the so-called  Little Ice Age  lasted only a few hundred years, peaking during the 16th and 17th centuries. During this time, average global temperatures were 1 to 1.5 degrees Celsius (2 to 3 degrees Fahrenheit) cooler than they are today.

A change of one or two degrees might not seem like a lot, but it was enough to cause some pretty massive effects. For instance, glaciers grew larger and sometimes engulfed whole mountain villages. Winters were longer than usual, limiting the growing seasons of  crops . In northern Europe, people deserted farms and villages to avoid  starvation .

One way scientists have learned about the Little Ice Age is by studying the rings of trees that are more than 300 years old. The thickness of  tree rings is related to the amount of the trees’ annual growth. This in turn is related to climate changes. During times of  drought  or cold, trees could not grow as much. The rings would be closer together.

Some climate changes are almost predictable . One example of regular climate change results from the warming of the surface waters of the tropical eastern Pacific Ocean. This warming is called El Niño —The Child—because it tends to begin around Christmas. In normal years,  trade winds blow steadily across the ocean from east to west, dragging warm surface water along in the same direction. This produces a shallow layer of warm water in the eastern Pacific and a buildup of warm water in the west. Every few years, normal winds falter and ocean currents reverse. This is El Niño. Warm water deepens in the eastern Pacific. This, in turn, produces  dramatic  climate changes. Rain decreases in Australia and southern Asia, and freak storms may pound Pacific islands and the west coast of the Americas. Within a year or two, El Niño ends, and climate systems return to normal.

Natural Causes of Climate Change Climate changes happen for a variety of reasons. Some of these reasons have to do with Earth’s  atmosphere . The climate change brought by El Niño, which relies on winds and ocean currents, is an example of natural atmospheric changes. Natural climate change can also be affected by forces outside Earth’s atmosphere. For instance, the 100,000-year cycles of ice ages are probably related to changes in the tilt of Earth’s  axis  and the shape of its  orbit  around the sun. Those planetary factors change slowly over time and affect how much of the sun’s energy reaches different parts of the world in different seasons.

The impact of large  meteorites on Earth could also cause climate change . The impact of a meteor would send millions of tons of  debris  into the atmosphere . This debris would block at least some of the sun’s rays, making it cold and dark. This climate change would severely limit what organisms could survive. Many  paleontologists believe the impact of a meteor or comet contributed to the extinction of the dinosaurs .  Dinosaurs simply could not survive in a cool, dark climate . Their bodies could not adjust to the cold, and the dark limited the growth of plants on which they fed.

Plate tectonics  also play a role in climate changes. Earth’s continental plates have moved a great deal over time. More than 200 million years ago, the continents were  merged together as one giant landmass called  Pangaea . As the continents broke apart and moved, their positions on Earth changed, and so did the movements of ocean currents. Both of these changes had effects on climate. Changes in  greenhouse gases in the atmosphere also have an impact on climate change. Gases like  carbon dioxide  trap the sun’s heat in Earth’s atmosphere, causing temperatures on the surface to rise.  Volcanoes —both on land and under the ocean—release greenhouse gases, so if the eruption only reaches the troposphere the additional gases contribute to warming. However, if the eruption is powerful enough to reach the stratosphere particles reflect sunlight back into space causing periods of cooling regionally.

Human Causes of Climate Change Some human activities release greenhouse gases—burning  fossil fuels for  transportation  and  electricity , or using  technology  that increases meat production, for instance. Trees absorb carbon dioxide, so cutting down forests for  timber  or  development  contributes to the greenhouse effect . So do factories that  emit   pollutants into the atmosphere.

Many scientists are worried that these activities are causing dramatic and dangerous changes in Earth’s climate. Average temperatures around the world have risen since about 1880, when scientists began tracking them. The seven warmest years of the 20th century occurred in the 1990s. This warming trend may be a sign that the greenhouse effect is increasing because of human activity. This climate change is often referred to as “ global warming .” Global warming is often linked to the burning of fossil fuels— coal ,  oil , and  natural gas —by industries and cars. Warming is also linked to the destruction of tropical forests. The University of California Riverside and NASA estimate human activity has increased the amount of carbon dioxide in the atmosphere by about 30 percent in the past 150 years. The amount of methane , a potent greehouse gas produced by decomposing plant and animal matter, is also increasing. Increased amounts of methane in Earth’s atmosphere are usually linked to  agricultural development  and industrial technology. As economies grow, populations consume more goods and throw away more materials. Large landfills , filled with decomposing waste, release tons of methane into the atmosphere. Chlorofluorocarbon (CFC) ,  hydrochlorofluorocarbon  (HCFC), and  hydrofluorocarbon  (HFC) chemicals are used in refrigeration and aerosol sprays. These chemicals are also greenhouse gases. Many countries are working to  phase out  their use, and some have laws to prevent companies from manufacturing them.

Global Warming

As the proportion of greenhouse gases in the atmosphere rises, so does the temperature of Earth. Climatologists worry that the global temperature will increase so much that ice caps will begin melting within the next several decades . This would cause the  sea level  to rise. Coastal areas, including many low-lying islands, would be flooded. Severe climate change may bring more severe weather patterns—more  hurricanes ,  typhoons , and  tornadoes . More precipitation would fall in some places and far less in others. Regions where crops now grow could become deserts. As climates change, so do the habitats for living things. Animals that live in an area may become threatened. Many human societies depend on specific crops for food , clothing, and trade . If the climate of an area changes, the people who live there may no longer be able to grow the crops they depend on for survival. Some scientists worry that as Earth warms,  tropical diseases such as  malaria ,  West Nile virus , and  yellow fever  will expand into more  temperate  regions. The temperature will continue to rise unless preventive steps are taken. Most climatologists agree that we must reduce the amount of greenhouse gases released into the atmosphere. There are many ways to do this, including:

• Drive less. Use  public transportation ,  carpool , walk, or ride a bike.
• Fly less. Airplanes produce huge amounts of greenhouse gas emissions .
• Reduce, reuse, and recycle.
• Plant a tree. Trees absorb carbon dioxide, keeping it out of the atmosphere.
• Use less electricity.
• Eat less meat. Cows are one of the biggest methane producers.
• Support alternative energy sources that don’t burn fossil fuels, such as  solar power  and  wind energy .

The climate has changed many times during Earth’s history, but the changes have occurred slowly, over thousands of years. Only since the Industrial Revolution have human activities begun to influence climate—and scientists are still working to understand what the  consequences might be.

Cool Warming Could the current phase of climate change cause another Little Ice Age? As strange as it sounds, some scientists believe it could. If melting glaciers release large amounts of freshwater into the oceans, this could disrupt the ocean conveyor belt, an important circulation system that moves seawater around the globe. Stopping this cycle could possibly cause cooling of 3 to 5 degrees Celsius (5-9 degrees Fahrenheit) in the ocean and atmosphere.

Early Squirrels The North American red squirrel has started breeding earlier in the year as a result of climate change. Food becomes available to the squirrels earlier because of warmer winters.

Worksheets & Handouts

Media credits.

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Illustrators

Educator reviewer, expert reviewer, last updated.

April 3, 2024

User Permissions

For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.

If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.

Text on this page is printable and can be used according to our Terms of Service .

Interactives

Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

Related Resources

Explore Greyhound Nation

• Loyola Today

Our Future Is Now - A Climate Change Essay by Francesca Minicozzi, '21

Francesca Minicozzi (class of 2021) is a Writing/Biology major who plans to study medicine after graduation. She wrote this essay on climate change for WR 355/Travel Writing, which she took while studying abroad in Newcastle in spring 2020. Although the coronavirus pandemic curtailed Francesca’s time abroad, her months in Newcastle prompted her to learn more about climate change. Terre Ryan Associate Professor, Writing Department

Our Future Is Now

By Francesca Minicozzi, '21 Writing and Biology Major

 “If you don’t mind me asking, how is the United States preparing for climate change?” my flat mate, Zac, asked me back in March, when we were both still in Newcastle. He and I were accustomed to asking each other about the differences between our home countries; he came from Cambridge, while I originated in Long Island, New York. This was one of our numerous conversations about issues that impact our generation, which we usually discussed while cooking dinner in our communal kitchen. In the moment of our conversation, I did not have as strong an answer for him as I would have liked. Instead, I informed him of the few changes I had witnessed within my home state of New York.

Zac’s response was consistent with his normal, diplomatic self. “I have been following the BBC news in terms of the climate crisis for the past few years. The U.K. has been working hard to transition to renewable energy sources. Similar to the United States, here in the United Kingdom we have converted over to solar panels too. My home does not have solar panels, but a lot of our neighbors have switched to solar energy in the past few years.”

“Our two countries are similar, yet so different,” I thought. Our conversation continued as we prepared our meals, with topics ranging from climate change to the upcoming presidential election to Britain’s exit from the European Union. However, I could not shake the fact that I knew so little about a topic so crucial to my generation.

After I abruptly returned home from the United Kingdom because of the global pandemic, my conversation with my flat mate lingered in my mind. Before the coronavirus surpassed climate change headlines, I had seen the number of internet postings regarding protests to protect the planet dramatically increase. Yet the idea of our planet becoming barren and unlivable in a not-so-distant future had previously upset me to the point where a part of me refused to deal with it. After I returned from studying abroad, I decided to educate myself on the climate crisis.

My quest for climate change knowledge required a thorough understanding of the difference between “climate change” and “global warming.” Climate change is defined as “a pattern of change affecting global or regional climate,” based on “average temperature and rainfall measurements” as well as the frequency of extreme weather events. 1   These varied temperature and weather events link back to both natural incidents and human activity. 2   Likewise, the term global warming was coined “to describe climate change caused by humans.” 3   Not only that, but global warming is most recently attributed to an increase in “global average temperature,” mainly due to greenhouse gas emissions produced by humans. 4

I next questioned why the term “climate change” seemed to take over the term “global warming” in the United States. According to Frank Luntz, a leading Republican consultant, the term “global warming” functions as a rather intimidating phrase. During George W. Bush’s first presidential term, Luntz argued in favor of using the less daunting phrase “climate change” in an attempt to overcome the environmental battle amongst Democrats and Republicans. 5   Since President Bush’s term, Luntz remains just one political consultant out of many politicians who has recognized the need to address climate change. In an article from 2019, Luntz proclaimed that political parties aside, the climate crisis affects everyone. Luntz argued that politicians should steer clear of trying to communicate “the complicated science of climate change,” and instead engage voters by explaining how climate change personally impacts citizens with natural disasters such as hurricanes, tornadoes, and forest fires. 6   He even suggested that a shift away from words like “sustainability” would gear Americans towards what they really want: a “cleaner, safer, healthier” environment. 7

The idea of a cleaner and heathier environment remains easier said than done. The Paris Climate Agreement, introduced in 2015, began the United Nations’ “effort to combat global climate change.” 8   This agreement marked a global initiative to “limit global temperature increase in this century to 2 degrees Celsius above preindustrial levels,” while simultaneously “pursuing means to limit the increase to 1.5 degrees.” 9    Every country on earth has joined together in this agreement for the common purpose of saving our planet. 10   So, what could go wrong here? As much as this sounds like a compelling step in the right direction for climate change, President Donald Trump thought otherwise. In June 2017, President Trump announced the withdrawal of the United States from the Paris Agreement with his proclamation of climate change as a “’hoax’ perpetrated by China.” 11   President Trump continued to question the scientific facts behind climate change, remaining an advocate for the expansion of domestic fossil fuel production. 12   He reversed environmental policies implemented by former President Barack Obama to reduce fossil fuel use. 13

Trump’s actions against the Paris Agreement, however, fail to represent the beliefs of Americans as a whole. The majority of American citizens feel passionate about the fight against climate change. To demonstrate their support, some have gone as far as creating initiatives including America’s Pledge and We Are Still In. 14   Although the United States officially exited the Paris Agreement on November 4, 2020, this withdrawal may not survive permanently. 15   According to experts, our new president “could rejoin in as short as a month’s time.” 16   This offers a glimmer of hope.

The Paris Agreement declares that the United States will reduce greenhouse gas emission levels by 26 to 28 percent by the year 2025. 17   As a leader in greenhouse gas emissions, the United States needs to accept the climate crisis for the serious challenge that it presents and work together with other nations. The concept of working coherently with all nations remains rather tricky; however, I remain optimistic. I think we can learn from how other countries have adapted to the increased heating of our planet. During my recent study abroad experience in the United Kingdom, I was struck by Great Britain’s commitment to combating climate change.

Since the United Kingdom joined the Paris Agreement, the country targets a “net-zero” greenhouse gas emission for 2050. 18   This substantial alteration would mark an 80% reduction of greenhouse gases from 1990, if “clear, stable, and well-designed policies are implemented without interruption.” 19   In order to stay on top of reducing emissions, the United Kingdom tracks electricity and car emissions, “size of onshore and offshore wind farms,” amount of homes and “walls insulated, and boilers upgraded,” as well as the development of government policies, including grants for electric vehicles. 20   A strong grip on this data allows the United Kingdom to target necessary modifications that keep the country on track for 2050. In my brief semester in Newcastle, I took note of these significant changes. The city of Newcastle is small enough that many students and faculty are able to walk or bike to campus and nearby essential shops. However, when driving is unavoidable, the majority of the vehicles used are electric, and many British citizens place a strong emphasis on carpooling to further reduce emissions. The United Kingdom’s determination to severely reduce greenhouse emissions is ambitious and particularly admirable, especially as the United States struggles to shy away from its dependence on fossil fuels.

So how can we, as Americans, stand together to combat global climate change? Here are five adjustments Americans can make to their homes and daily routines that can dramatically make a difference:

• Stay cautious of food waste. Studies demonstrate that “Americans throw away up to 40 percent of the food they buy.” 21   By being more mindful of the foods we purchase, opting for leftovers, composting wastes, and donating surplus food to those in need, we can make an individual difference that impacts the greater good. 22   
• Insulate your home. Insulation functions as a “cost-effective and accessible” method to combat climate change. 23   Homes with modern insulation reduce energy required to heat them, leading to a reduction of emissions and an overall savings; in comparison, older homes can “lose up to 35 percent of heat through their walls.” 24   
• Switch to LED Lighting. LED stands for “light-emitting diodes,” which use “90 percent less energy than incandescent bulbs and half as much as compact fluorescents.” 25   LED lights create light without producing heat, and therefore do not waste energy. Additionally, these lights have a longer duration than other bulbs, which means they offer a continuing savings. 26  
• Choose transportation wisely. Choose to walk or bike whenever the option presents itself. If walking or biking is not an option, use an electric or hybrid vehicle which emits less harmful gases. Furthermore, reduce the number of car trips taken, and carpool with others when applicable. 
• Finally, make your voice heard. The future of our planet remains in our hands, so we might as well use our voices to our advantage. Social media serves as a great platform for this. Moreover, using social media to share helpful hints to combat climate change within your community or to promote an upcoming protest proves beneficial in the long run. If we collectively put our voices to good use, together we can advocate for change.

As many of us are stuck at home due to the COVID-19 pandemic, these suggestions are slightly easier to put into place. With numerous “stay-at-home” orders in effect, Americans have the opportunity to make significant achievements for climate change. Personally, I have taken more precautions towards the amount of food consumed within my household during this pandemic. I have been more aware of food waste, opting for leftovers when too much food remains. Additionally, I have realized how powerful my voice is as a young college student. Now is the opportunity for Americans to share how they feel about climate change. During this unprecedented time, our voice is needed now more than ever in order to make a difference.

However, on a much larger scale, the coronavirus outbreak has shed light on reducing global energy consumption. Reductions in travel, both on the roads and in the air, have triggered a drop in emission rates. In fact, the International Energy Agency predicts a 6 percent decrease in energy consumption around the globe for this year alone. 27   This drop is “equivalent to losing the entire energy demand of India.” 28   Complete lockdowns have lowered the global demand for electricity and slashed CO2 emissions. However, in New York City, the shutdown has only decreased carbon dioxide emissions by 10 percent. 29   This proves that a shift in personal behavior is simply not enough to “fix the carbon emission problem.” 30   Climate policies aimed to reduce fossil fuel production and promote clean technology will be crucial steppingstones to ameliorating climate change effects. Our current reduction of greenhouse gas emissions serves as “the sort of reduction we need every year until net-zero emissions are reached around 2050.” 31   From the start of the coronavirus pandemic, politicians came together for the common good of protecting humanity; this demonstrates that when necessary, global leaders are capable of putting humankind above the economy. 32

After researching statistics comparing the coronavirus to climate change, I thought back to the moment the virus reached pandemic status. I knew that a greater reason underlay all of this global turmoil. Our globe is in dire need of help, and the coronavirus reminds the world of what it means to work together. This pandemic marks a turning point in global efforts to slow down climate change. The methods we enact towards not only stopping the spread of the virus, but slowing down climate change, will ultimately depict how humanity will arise once this pandemic is suppressed. The future of our home planet lies in how we treat it right now. 

• “Climate Change: What Do All the Terms Mean?,” BBC News (BBC, May 1, 2019), https://www.bbc.com/news/science-environment-48057733 )
• Ibid. 
• Kate Yoder, “Frank Luntz, the GOP's Message Master, Calls for Climate Action,” Grist (Grist, July 26, 2019), https://grist.org/article/the-gops-most-famous-messaging-strategist-calls-for-climate-action
• Melissa Denchak, “Paris Climate Agreement: Everything You Need to Know,” NRDC, April 29, 2020, https://www.nrdc.org/stories/paris-climate-agreement-everything-you-need-know)
• “Donald J. Trump's Foreign Policy Positions,” Council on Foreign Relations (Council on Foreign Relations), accessed May 7, 2020, https://www.cfr.org/election2020/candidate-tracker/donald-j.-trump?gclid=CjwKCAjw4871BRAjEiwAbxXi21cneTRft_doA5if60euC6QCL7sr-Jwwv76IkgWaUTuyJNx9EzZzRBoCdjsQAvD_BwE#climate and energy )
• David Doniger, “Paris Climate Agreement Explained: Does Congress Need to Sign Off?,” NRDC, December 15, 2016, https://www.nrdc.org/experts/david-doniger/paris-climate-agreement-explained-does-congress-need-sign )
• “How the UK Is Progressing,” Committee on Climate Change, March 9, 2020, https://www.theccc.org.uk/what-is-climate-change/reducing-carbon-emissions/how-the-uk-is-progressing/)
• Ibid.  
• “Top 10 Ways You Can Fight Climate Change,” Green America, accessed May 7, 2020, https://www.greenamerica.org/your-green-life/10-ways-you-can-fight-climate-change )
• Matt McGrath, “Climate Change and Coronavirus: Five Charts about the Biggest Carbon Crash,” BBC News (BBC, May 5, 2020), https://www.bbc.com/news/amp/science-environment-52485712 )

• Donor Portal Sign In
• PBS Sign In

Climate question: What’s the difference between global warming and climate change?

When discussing climate, the terms are often viewed as interchangeable. But, as my own mother wrote in to our climate questions survey , the difference isn’t always clear.

If my own mom asked the question, I thought other members of our audience might appreciate some clarification too. So, here it is:

Simply put, climate change is any change in the Earth’s climate at any point throughout Earth’s history.

But there’s a difference between climate change and human-caused climate change. Humans are currently the biggest contributor to global warming by burning fossil fuels that create greenhouse gases, climate expert and Director of Climate Communication Susan Hassol said.

“The sunlight comes down from the sun, it heats up the earth,” she said. “The earth re-radiates that heat back towards space. But some of these molecules, like carbon dioxide, trap some of that heat that the earth's re-radiating back towards space -- trap it in the climate system and make the earth warmer than it would otherwise be.”

Global warming is the long-term rise in temperature on the planet. Like climate change, global warming can occur – and has occurred – naturally throughout our planet’s history. But due to human’s impact on climate change, the global temperature no longer aligns with natural trends.

“If we look at all the volcanic eruptions, climate would have actually cooled slightly over the last hundred years. Instead, climate has warmed very strongly over the last hundred years,” Hassol said. “And we know why. It's because of the burning of coal, oil and gas and the clearing of forests. It's the human activity.”

Human activity, has led to unprecedented change in the planet’s climate Hassol said, and these changes come with adverse effects.

Global warming is one effect of climate change, according to the National Oceanic and Atmospheric Administration , but it’s not the only one. One way to think of the relationship between the two is, if climate change is the illness, global warming is a symptom, along with severe and frequent rain events, heatwaves and wildfires.

If no action is taken to reduce carbon emissions, climate change and its effects will only get worse, experts say , leading to more frequent and severe weather events threatening human life and biodiversity.

How to reduce your impact

There are steps people can take to reduce their carbon footprint and lessen their contribution to climate change and global warming. But, conserving energy by turning of lights and unplugging appliances are small drops in the bucket, Hassol said.

“Turning off your lights is very small,” she said. “I'm not saying you shouldn't do it. It's still good. It's always good to conserve energy, but you should worry about the things that are big.”

Instead, Hassol recommends individuals consider bigger conservation practices, though they might require some form of lifestyle change. Effective ways to reduce a carbon foot print, she said, are to drive and fly less and to consider the number of children you might have in family planning.

“If you live in the United States, having one fewer child makes a really big difference because children born in this culture use a lot of energy and a lot of resources,” Hassol said. “That's a personal decision, but ... it's the single biggest thing that anybody can do.”

It’s too late to reverse the effects of climate change, Hassol said. Though unlikely, we’d need a world-wide shift away from fossil fuels to stop global warming from getting worse.

Hassol also recommends other personal choices, like reducing food waste, eating less meat and dairy that contributes to deforestation and carbon emissions and avoiding banks that fund the fossil fuel industry .

“The four biggest U.S. banks are the four largest funders of that fossil fuel expansion. Chase, Citi, Wells Fargo and Bank of America,” she said. “So, if you have your money in those banks and you use those banks for your credit cards, you're actually contributing to that problem.”

In the meantime, these conservation practices can prevent the effects climate change – like global warming – from getting worse, Hassol said.

Changing climate language

The words we use to talk about climate change and its effects are essential to make sure we’re communicating the right message, Hassol said. But this also means we should choose our words carefully.

When discussing climate change, Hassol recommends referring to it as human-caused climate change to specify that the effects we’re seeing today are not natural, and instead brought on by human action.

“Some people hear climate change and they think, ‘oh, well then, the change we're seeing now could be natural,’” she said. “But the science is very clear that this current warming is not natural.”

There are also a few phrases she’d recommend over global warming, which can be confusing and inaccurate when used in conversation.

“[The] problem with global warming is that it sounds nice to some people, right? Warmth is generally a positive thing.,” Hassol said. “Another problem is that it speaks mainly to rising temperatures, and it doesn't invoke all the other things that come along with the rising temperatures: heavy rainfall that causes flooding, stronger, more destructive hurricanes [and] larger, more intense wildfires.”

Instead, Hassol recommends phrases like climate disruption, global heating and global weirding to cover all the bases of climate change and its effects.

• History & Society
• Science & Tech
• Biographies
• Animals & Nature
• Geography & Travel
• Arts & Culture
• Games & Quizzes
• On This Day
• One Good Fact
• New Articles
• Lifestyles & Social Issues
• Philosophy & Religion
• Politics, Law & Government
• World History
• Health & Medicine
• Browse Biographies
• Birds, Reptiles & Other Vertebrates
• Bugs, Mollusks & Other Invertebrates
• Environment
• Fossils & Geologic Time
• Entertainment & Pop Culture
• Sports & Recreation
• Visual Arts
• Demystified
• Image Galleries
• Infographics
• Top Questions
• Britannica Kids
• Saving Earth
• Space Next 50
• Student Center
• Introduction & Top Questions
• Climatic variation since the last glaciation
• The greenhouse effect
• Radiative forcing
• Water vapour
• Carbon dioxide
• Surface-level ozone and other compounds
• Nitrous oxides and fluorinated gases
• Land-use change
• Stratospheric ozone depletion
• Volcanic aerosols
• Variations in solar output
• Variations in Earth’s orbit
• Water vapour feedback
• Cloud feedbacks
• Ice albedo feedback
• Carbon cycle feedbacks
• Modern observations
• Prehistorical climate records
• Theoretical climate models
• Patterns of warming
• Precipitation patterns
• Regional predictions
• Ice melt and sea level rise
• Ocean circulation changes
• Tropical cyclones
• Environmental consequences of global warming
• Socioeconomic consequences of global warming

How does global warming work?

Where does global warming occur in the atmosphere, why is global warming a social problem, where does global warming affect polar bears.

global warming

Our editors will review what you’ve submitted and determine whether to revise the article.

• U.S. Department of Transportation - Global Warming: A Science Overview
• NOAA Climate.gov - Climate Change: Global Temperature
• Natural Resources Defense Council - Global Warming 101
• American Institute of Physics - The discovery of global warming
• LiveScience - Causes of Global Warming
• global warming - Children's Encyclopedia (Ages 8-11)
• global warming - Student Encyclopedia (Ages 11 and up)
• Table Of Contents

Human activity affects global surface temperatures by changing Earth ’s radiative balance—the “give and take” between what comes in during the day and what Earth emits at night. Increases in greenhouse gases —i.e., trace gases such as carbon dioxide and methane that absorb heat energy emitted from Earth’s surface and reradiate it back—generated by industry and transportation cause the atmosphere to retain more heat, which increases temperatures and alters precipitation patterns.

Global warming, the phenomenon of increasing average air temperatures near Earth’s surface over the past one to two centuries, happens mostly in the troposphere , the lowest level of the atmosphere, which extends from Earth’s surface up to a height of 6–11 miles. This layer contains most of Earth’s clouds and is where living things and their habitats and weather primarily occur.

Continued global warming is expected to impact everything from energy use to water availability to crop productivity throughout the world. Poor countries and communities with limited abilities to adapt to these changes are expected to suffer disproportionately. Global warming is already being associated with increases in the incidence of severe and extreme weather, heavy flooding , and wildfires —phenomena that threaten homes, dams, transportation networks, and other facets of human infrastructure. Learn more about how the IPCC’s Sixth Assessment Report, released in 2021, describes the social impacts of global warming.

Polar bears live in the Arctic , where they use the region’s ice floes as they hunt seals and other marine mammals . Temperature increases related to global warming have been the most pronounced at the poles, where they often make the difference between frozen and melted ice. Polar bears rely on small gaps in the ice to hunt their prey. As these gaps widen because of continued melting, prey capture has become more challenging for these animals.

Recent News

global warming , the phenomenon of increasing average air temperatures near the surface of Earth over the past one to two centuries. Climate scientists have since the mid-20th century gathered detailed observations of various weather phenomena (such as temperatures, precipitation , and storms) and of related influences on climate (such as ocean currents and the atmosphere’s chemical composition). These data indicate that Earth’s climate has changed over almost every conceivable timescale since the beginning of geologic time and that human activities since at least the beginning of the Industrial Revolution have a growing influence over the pace and extent of present-day climate change .

Giving voice to a growing conviction of most of the scientific community , the Intergovernmental Panel on Climate Change (IPCC) was formed in 1988 by the World Meteorological Organization (WMO) and the United Nations Environment Program (UNEP). The IPCC’s Sixth Assessment Report (AR6), published in 2021, noted that the best estimate of the increase in global average surface temperature between 1850 and 2019 was 1.07 °C (1.9 °F). An IPCC special report produced in 2018 noted that human beings and their activities have been responsible for a worldwide average temperature increase between 0.8 and 1.2 °C (1.4 and 2.2 °F) since preindustrial times, and most of the warming over the second half of the 20th century could be attributed to human activities.

AR6 produced a series of global climate predictions based on modeling five greenhouse gas emission scenarios that accounted for future emissions, mitigation (severity reduction) measures, and uncertainties in the model projections. Some of the main uncertainties include the precise role of feedback processes and the impacts of industrial pollutants known as aerosols , which may offset some warming. The lowest-emissions scenario, which assumed steep cuts in greenhouse gas emissions beginning in 2015, predicted that the global mean surface temperature would increase between 1.0 and 1.8 °C (1.8 and 3.2 °F) by 2100 relative to the 1850–1900 average. This range stood in stark contrast to the highest-emissions scenario, which predicted that the mean surface temperature would rise between 3.3 and 5.7 °C (5.9 and 10.2 °F) by 2100 based on the assumption that greenhouse gas emissions would continue to increase throughout the 21st century. The intermediate-emissions scenario, which assumed that emissions would stabilize by 2050 before declining gradually, projected an increase of between 2.1 and 3.5 °C (3.8 and 6.3 °F) by 2100.

Many climate scientists agree that significant societal, economic, and ecological damage would result if the global average temperature rose by more than 2 °C (3.6 °F) in such a short time. Such damage would include increased extinction of many plant and animal species, shifts in patterns of agriculture , and rising sea levels. By 2015 all but a few national governments had begun the process of instituting carbon reduction plans as part of the Paris Agreement , a treaty designed to help countries keep global warming to 1.5 °C (2.7 °F) above preindustrial levels in order to avoid the worst of the predicted effects. Whereas authors of the 2018 special report noted that should carbon emissions continue at their present rate, the increase in average near-surface air temperature would reach 1.5 °C sometime between 2030 and 2052, authors of the AR6 report suggested that this threshold would be reached by 2041 at the latest.

The AR6 report also noted that the global average sea level had risen by some 20 cm (7.9 inches) between 1901 and 2018 and that sea level rose faster in the second half of the 20th century than in the first half. It also predicted, again depending on a wide range of scenarios, that the global average sea level would rise by different amounts by 2100 relative to the 1995–2014 average. Under the report’s lowest-emission scenario, sea level would rise by 28–55 cm (11–21.7 inches), whereas, under the intermediate emissions scenario, sea level would rise by 44–76 cm (17.3–29.9 inches). The highest-emissions scenario suggested that sea level would rise by 63–101 cm (24.8–39.8 inches) by 2100.

The scenarios referred to above depend mainly on future concentrations of certain trace gases, called greenhouse gases , that have been injected into the lower atmosphere in increasing amounts through the burning of fossil fuels for industry, transportation , and residential uses. Modern global warming is the result of an increase in magnitude of the so-called greenhouse effect , a warming of Earth’s surface and lower atmosphere caused by the presence of water vapour , carbon dioxide , methane , nitrous oxides , and other greenhouse gases. In 2014 the IPCC first reported that concentrations of carbon dioxide, methane, and nitrous oxides in the atmosphere surpassed those found in ice cores dating back 800,000 years.

Of all these gases, carbon dioxide is the most important, both for its role in the greenhouse effect and for its role in the human economy. It has been estimated that, at the beginning of the industrial age in the mid-18th century, carbon dioxide concentrations in the atmosphere were roughly 280 parts per million (ppm). By the end of 2022 they had risen to 419 ppm, and, if fossil fuels continue to be burned at current rates, they are projected to reach 550 ppm by the mid-21st century—essentially, a doubling of carbon dioxide concentrations in 300 years.

A vigorous debate is in progress over the extent and seriousness of rising surface temperatures, the effects of past and future warming on human life, and the need for action to reduce future warming and deal with its consequences. This article provides an overview of the scientific background related to the subject of global warming. It considers the causes of rising near-surface air temperatures, the influencing factors, the process of climate research and forecasting, and the possible ecological and social impacts of rising temperatures. For an overview of the public policy developments related to global warming occurring since the mid-20th century, see global warming policy . For a detailed description of Earth’s climate, its processes, and the responses of living things to its changing nature, see climate . For additional background on how Earth’s climate has changed throughout geologic time , see climatic variation and change . For a full description of Earth’s gaseous envelope, within which climate change and global warming occur, see atmosphere .

What Is Climate Change?

Climate change is a long-term change in the average weather patterns that have come to define Earth’s local, regional and global climates. These changes have a broad range of observed effects that are synonymous with the term.

Changes observed in Earth’s climate since the mid-20th century are driven by human activities, particularly fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth’s atmosphere, raising Earth’s average surface temperature. Natural processes, which have been overwhelmed by human activities, can also contribute to climate change, including internal variability (e.g., cyclical ocean patterns like El Niño, La Niña and the Pacific Decadal Oscillation) and external forcings (e.g., volcanic activity, changes in the Sun’s energy output , variations in Earth’s orbit ).

Scientists use observations from the ground, air, and space, along with computer models , to monitor and study past, present, and future climate change. Climate data records provide evidence of climate change key indicators, such as global land and ocean temperature increases; rising sea levels; ice loss at Earth’s poles and in mountain glaciers; frequency and severity changes in extreme weather such as hurricanes, heatwaves, wildfires, droughts, floods, and precipitation; and cloud and vegetation cover changes.

“Climate change” and “global warming” are often used interchangeably but have distinct meanings. Similarly, the terms "weather" and "climate" are sometimes confused, though they refer to events with broadly different spatial- and timescales.

What Is Global Warming?

Global warming is the long-term heating of Earth’s surface observed since the pre-industrial period (between 1850 and 1900) due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth’s atmosphere. This term is not interchangeable with the term "climate change."

Since the pre-industrial period, human activities are estimated to have increased Earth’s global average temperature by about 1 degree Celsius (1.8 degrees Fahrenheit), a number that is currently increasing by more than 0.2 degrees Celsius (0.36 degrees Fahrenheit) per decade. The current warming trend is unequivocally the result of human activity since the 1950s and is proceeding at an unprecedented rate over millennia.

Weather vs. Climate

“If you don’t like the weather in New England, just wait a few minutes.” - Mark Twain

Weather refers to atmospheric conditions that occur locally over short periods of time—from minutes to hours or days. Familiar examples include rain, snow, clouds, winds, floods, or thunderstorms.

Climate, on the other hand, refers to the long-term (usually at least 30 years) regional or even global average of temperature, humidity, and rainfall patterns over seasons, years, or decades.

Find Out More: A Guide to NASA’s Global Climate Change Website

This website provides a high-level overview of some of the known causes, effects and indications of global climate change:

Evidence. Brief descriptions of some of the key scientific observations that our planet is undergoing abrupt climate change.

Causes. A concise discussion of the primary climate change causes on our planet.

Effects. A look at some of the likely future effects of climate change, including U.S. regional effects.

Vital Signs. Graphs and animated time series showing real-time climate change data, including atmospheric carbon dioxide, global temperature, sea ice extent, and ice sheet volume.

Earth Minute. This fun video series explains various Earth science topics, including some climate change topics.

Other NASA Resources

Goddard Scientific Visualization Studio. An extensive collection of animated climate change and Earth science visualizations.

Sea Level Change Portal. NASA's portal for an in-depth look at the science behind sea level change.

NASA’s Earth Observatory. Satellite imagery, feature articles and scientific information about our home planet, with a focus on Earth’s climate and environmental change.

Header image is of Apusiaajik Glacier, and was taken near Kulusuk, Greenland, on Aug. 26, 2018, during NASA's Oceans Melting Greenland (OMG) field operations. Learn more here . Credit: NASA/JPL-Caltech

Search the United Nations

• What Is Climate Change
• Myth Busters
• Renewable Energy
• Finance & Justice
• Initiatives
• Sustainable Development Goals
• Paris Agreement
• Climate Ambition Summit 2023
• Climate Conferences
• Press Material
• Communications Tips

Causes and Effects of Climate Change

Fossil fuels – coal, oil and gas – are by far the largest contributor to global climate change, accounting for over 75 per cent of global greenhouse gas emissions and nearly 90 per cent of all carbon dioxide emissions. As greenhouse gas emissions blanket the Earth, they trap the sun’s heat. This leads to global warming and climate change. The world is now warming faster than at any point in recorded history. Warmer temperatures over time are changing weather patterns and disrupting the usual balance of nature. This poses many risks to human beings and all other forms of life on Earth. 

Heatwaves put bees at risk

Eleven-year-old Markela is a fifth generation beekeeper, but climate change is making it so that she may not be able to carry on the family tradition. Wildfires, heatwaves, and droughts that are increasing in intensity and frequency due to the climate crisis, put bees and the ecosystems at risk.

Healing Chile’s Huapi Island

On Chile’s Huapi Island, native forests have become fragmented, making the soils poorer and drier and leaving the population vulnerable to the effects of climate change. Now, thanks to the restoration efforts of Indigenous Peoples, native trees are making a comeback.

Early warning systems are saving lives in Central Asia

As Central Asia grapples with the increasing frequency and severity of climate-induced hazards, the importance of robust early warning systems cannot be overstated. However, countries need both technical knowledge and resources to effectively implement these systems on a large scale. Japan has been a reliable ally for countries, helping advance early warning systems and increase resilience in the region.

Facts and figures

• What is climate change?
• Causes and effects
• Myth busters

Cutting emissions

• Explaining net zero
• High-level expert group on net zero
• Checklists for credibility of net-zero pledges
• Greenwashing
• What you can do

Clean energy

• Renewable energy – key to a safer future
• What is renewable energy
• Five ways to speed up the energy transition
• Why invest in renewable energy
• Clean energy stories
• A just transition

Adapting to climate change

• Climate adaptation
• Early warnings for all
• Youth voices

Financing climate action

• Finance and justice
• Loss and damage
• $100 billion commitment
• Why finance climate action
• Biodiversity
• Human Security

International cooperation

• What are Nationally Determined Contributions
• Acceleration Agenda
• Climate Ambition Summit
• Climate conferences (COPs)
• Youth Advisory Group
• Action initiatives
• Secretary-General’s speeches
• Press material
• Fact sheets
• Communications tips

Try AI-powered search

The past, present and future of climate change

Climate issue: replacing the fossil-fuel technology which is reshaping the climate remains a massive task.

Your browser does not support the <audio> element.

I N THE EARLY 19th century Joseph Fourier, a French pioneer in the study of heat, showed that the atmosphere kept the Earth warmer than it would be if exposed directly to outer space. By 1860 John Tyndall, an Irish physicist, had found that a key to this warming lay in an interesting property of some atmospheric gases, including carbon dioxide. They were transparent to visible light but absorbed infrared radiation, which meant they let sunlight in but impeded heat from getting out. By the turn of the 20th century Svante Arrhenius, a Swedish chemist, was speculating that low carbon-dioxide levels might have caused the ice ages, and that the industrial use of coal might warm the planet.

What none foresaw was how fast, and how far, the use of fossil fuels would grow (see chart above). In 1900 the deliberate burning of fossil fuels—almost entirely, at the time, coal—produced about 2bn tonnes of carbon dioxide. By 1950 industrial emissions were three times that much. Today they are close to 20 times that much.

That explosion of fossil-fuel use is inseparable from everything else which made the 20th century unique in human history. As well as providing unprecedented access to energy for manufacturing, heating and transport, fossil fuels also made almost all the Earth’s other resources vastly more accessible. The nitrogen-based explosives and fertilisers which fossil fuels made cheap and plentiful transformed mining, warfare and farming. Oil refineries poured forth the raw materials for plastics. The forests met the chainsaw.

In no previous century had the human population doubled. In the 20th century it came within a whisker of doubling twice. In no previous century had world GDP doubled. In the 20th century it doubled four times and then some.

An appendix to a report prepared by America’s Presidential Science Advisory Committee in 1965 marks the first time that politicians were made directly aware of the likely climate impact of all this. In the first half of the century scientists believed that almost all the carbon dioxide given off by industry would be soaked up by the oceans. But Roger Revelle, an oceanographer, had shown in the 1950s that this was not the case. He had also instituted efforts to measure year-on-year changes in the atmosphere’s carbon-dioxide level. By 1965 it was clear that it was steadily rising.

The summary of what that rise meant, novel when sent to the president, is now familiar. Carbon stored up in the crust over hundreds of millions of years was being released in a few generations; if nothing were done, temperatures and sea levels would rise to an extent with no historic parallel. Its suggested response seems more bizarre: trillions of ping-pong balls on the ocean surface might reflect back more of the sun’s rays, providing a cooling effect.

The big difference between 1965 and now, though, is what was then a peculiar prediction is now an acute predicament. In 1965 the carbon-dioxide level was 320 parts per million (ppm); unprecedented, but only 40ppm above what it had been two centuries earlier. The next 40ppm took just three decades. The 40ppm after that took just two. The carbon-dioxide level is now 408ppm, and still rising by 2ppm a year.

Records of ancient atmospheres provide an unnerving context for this precipitous rise. Arrhenius was right in his hypothesis that a large part of the difference in temperature between the ice ages and the warm “interglacials” that separated them was down to carbon dioxide. Evidence from Antarctic ice cores shows the two going up and down together over hundreds of thousands of years. In interglacials the carbon-dioxide level is 1.45 times higher than it is in the depths of an ice age. Today’s level is 1.45 times higher than that of a typical interglacial. In terms of carbon dioxide’s greenhouse effect, today’s world is already as far from that of the 18th century as the 18th century was from the ice age (see “like an ice age” chart).

Not all the difference in temperature between interglacials and ice ages was because of carbon dioxide. The reflection of sunlight by the expanded ice caps added to the cooling, as did the dryness of the atmosphere. But the ice cores make it clear that what the world is seeing is a sudden and dramatic shift in fundamental parameter of the planet’s climate. The last time the Earth had a carbon-dioxide level similar to today’s, it was on average about 3°C warmer. Greenland’s hills were green. Parts of Antarctica were fringed with forest. The water now frozen over those landscapes was in the oceans, providing sea levels 20 metres higher than today’s.

Ping-pong ding-dong

There is no evidence that President Lyndon Johnson read the 1965 report. He certainly didn’t act on it. The idea of deliberately changing the Earth’s reflectivity, whether with ping-pong balls or by other means, was outlandish. The idea that the fuels on which the American and world economies were based should be phased out would have seemed even more so. And there was, back then, no conclusive proof that humans were warming the Earth.

Proof took time. Carbon dioxide is not the only greenhouse gas. Methane and nitrous oxide trap heat, too. So does water vapour, which thereby amplifies the effects of the others. Because warmth drives evaporation, a world warmed by carbon dioxide will have a moister atmosphere, which will make it warmer still. But water vapour also condenses into clouds—some of which cool the world and some of which warm it further. Then and now, the complexities of such processes make precision about the amount of warming expected for a given carbon-dioxide level unachievable.

Further complexities abound. Burning fossil fuels releases particles small enough to float in the air as well as carbon dioxide. These “aerosols” warm the atmosphere, but also shade and thereby cool the surface below; in the 1960s and 1970s some thought their cooling power might overpower the warming effects of carbon dioxide. Volcanic eruptions also produce surface-cooling aerosols, the effects of which can be global; the brightness of the sun varies over time, too, in subtle ways. And even without such external “forcings”, the internal dynamics of the climate will shift heat between the oceans and atmosphere over various timescales. The best known such shifts, the El Niño events seen a few times a decade, show up in the mean surface temperature of the world as a whole.

These complexities meant that, for a time, there was doubt about greenhouse warming, which the fossil-fuel lobby deliberately fostered. There is no legitimate doubt today. Every decade since the 1970s has been warmer than the one before, which rules out natural variations. It is possible to compare climate models that account for just the natural forcings of the 20th century with those that take into account human activities, too. The effects of industry are not statistically significant until the 1980s. Now they are indisputable.

At the Earth Summit in Rio de Janeiro in 1992, around the time that the human effect on the climate was becoming clearly discernible, the nations of the world signed the UN Framework Convention on Climate Change ( UNFCCC ). By doing so they promised to “prevent dangerous anthropogenic interference with the climate system”.

Since then humans have emitted 765bn more tonnes of carbon dioxide; the 2010s have been, on average, some 0.5°C hotter than the 1980s. The Intergovernmental Panel on Climate Change ( IPCC ) estimates that mean surface temperature is now 1°C above what it was in the pre-industrial world, and rising by about 0.2°C a decade. In mid- to high-northern latitudes, and in some other places, there has already been a warming of 1.5°C or more; much of the Arctic has seen more than 3°C (see map).

The figure of 1.5°C matters because of the Paris agreement, signed by the parties to the UNFCCC in 2015. That agreement added targets to the original goal of preventing “dangerous interference” in the climate: the signatories promised to hold global warming “well below” 2°C above pre-industrial temperatures and to make “efforts to limit the temperature increase to 1.5°C”.

Neither 1.5°C nor 2°C has any particular significance outside these commitments. Neither marks a threshold beyond which the world becomes uninhabitable, or a tipping point of no return. Conversely, they are not limits below which climate change has no harmful effects. There must be thresholds and tipping points in a warming world. But they are not well enough understood for them to be associated with specific rises in mean temperature.

For the most part the harm warming will do—making extreme weather events more frequent and/or more intense, changing patterns of rainfall and drought, disrupting ecosystems, driving up sea levels—simply gets greater the more warming there is. And its global toll could well be so great that individual calamities add little.

At present further warming is certain, whatever the world does about its emissions. This is in part because, just as a pan of water on a hob takes time to boil when the gas below is lit, so the world’s mean temperature is taking time to respond to the heating imposed by the sky above. It is also because what matters is the total amount of greenhouse gas in the atmosphere, not the rate at which it increases. Lowering annual emissions merely slows the rate at which the sky’s heating effect gets stronger; surface warming does not come to an end until the greenhouse-gas level is no longer increasing at all. If warming is to be held to 1.5°C that needs to happen by around 2050; if it is to be kept well below 2°C there are at best a couple more decades to play with.

Revolution in reverse

Thus, in its simplest form, the 21st century’s supertanker-U-turn challenge: reversing the 20-fold increase in emissions the 20th century set in train, and doing so at twice the speed. Replacing everything that burns gas or coal or oil to heat a home or drive a generator or turn a wheel. Rebuilding all the steelworks; refashioning the cement works; recycling or replacing the plastics; transforming farms on all continents. And doing it all while expanding the economy enough to meet the needs and desires of a population which may well be half again as large by 2100 as it is today.

“Integrated assessment models”, which combine economic dynamics with assumptions about the climate, suggest that getting to zero emissions by 2050 means halving current emissions by 2030. No nation is on course to do that. The national pledges made at the time of the Paris agreement would, if met, see global emissions in 2030 roughly equivalent to today’s. Even if emissions decline thereafter, that suggests a good chance of reaching 3°C.

Some countries already emit less than half as much carbon dioxide as the global average. But they are countries where many people desperately want more of the energy, transport and resources that fossil fuels have provided richer nations over the past century. Some of those richer nations have now pledged to rejoin the low emitters. Britain has legislated for massive cuts in emissions by 2050. But the fact that legislation calls for something does not mean it will happen. And even if it did, at a global level it would remain a small contribution.

This is one of the problems of trying to stop warming through emission policies. If you reduce emissions and no one else does, you face roughly the same climate risk as before. If everyone else reduces and you do not, you get almost as much benefit as you would if you had joined in. It is a collective-action problem that only gets worse as mitigation gets more ambitious.

What is more, the costs and benefits are radically uncertain and unevenly distributed. Most of the benefit from curtailing climate change will almost certainly be felt by people in developing countries; most of the cost of emission cuts will be felt elsewhere. And most of the benefits will be accrued not today, but in 50 or 100 years.

It is thus fitting that the most striking recent development in climate politics is the rise of activism among the young. For people born, like most of the world’s current leaders, well before 1980, the second half of the 21st century seems largely hypothetical. For people born after 2000, like Greta Thunberg, a Swedish activist, and some 2.6bn others, it seems like half their lives. This gives moral weight to their demands that the Paris targets be met, with emissions halved by 2030. But the belief that this can be accomplished through a massive influx of “political will” severely underestimates the challenge.

It is true that, after a spectacular boom in renewable-energy installations, electricity from the wind and the sun now accounts for 7% of the world’s total generation. The price of such installations has tumbled; they are now often cheaper than fossil-fuel generating capacity, though storage capacity and grid modifications may make that advantage less at the level of the whole electricity system.

One step towards halving emissions by 2030 would be to ramp such renewable-electricity generation up to half the total. This would mean a fivefold-to-tenfold increase in capacity. Expanding hydroelectricity and nuclear power would lessen the challenge of all those square kilometres of solar panels and millions of windmills. But increased demand would heighten it. Last year world electricity demand rose by 3.7%. Eleven years of such growth would see demand in 2030 half as large again as demand in 2018. All that new capacity would have to be fossil-fuel-free.

And electricity is the easy part. Emissions from generating plants are less than 40% of all industrial emissions. Progress on reducing emissions from industrial processes and transport is far less advanced. Only 0.5% of the world’s vehicles are electric, according to Bloomberg NEF , a research firm. If that were to increase to 50% without increasing emissions the production of fossil-fuel-free electricity would have to shoot up yet further.

The investment needed to bring all this about would be unprecedented. So would the harm to sections of the fossil economy. According to Carbon Tracker, a think-tank, more than half the money the big oil companies plan to spend on new fields would be worthless in a world that halved emissions by 2030. The implications extend to geopolitics. A world in which the oil price is no longer of interest is one very different from that of the past century.

Putting off to tomorrow

Dislocation on such a scale might be undertaken if a large asteroid on a fixed trajectory were set to devastate North America on January 1st 2031. It is far harder to imagine when the victims are less readily identifiable and the harms less cosmically certain—even if they eventually turn out to be comparable in scale. Realising this, the climate negotiators of the world have, over the past decade, increasingly come to depend on the idea of “negative emissions”. Instead of not putting carbon dioxide into the atmosphere at all, put it in and take it out later. By evoking ever larger negative emissions later in the century it is possible to accept a later peak and a slower reduction while still being able to say that you will end up within the 1.5°C or 2°C limit (see “four futures” chart).

Unfortunately, technologies capable of delivering negative emissions of billions of tonnes a year for reasonable prices over decades do not exist. There are, though, ideas about how they could be brought into being. One favoured by modellers involves first growing plants, which suck up atmospheric carbon dioxide through photosynthesis, and then burning them in power stations which store the carbon dioxide they produce underground. A surmountable problem is that no such systems yet exist at scale. A much tougher one is that the amount of land required for growing all those energy crops would be enormous.

This opens up a dilemma. Given that reducing emissions seems certain not to deliver quickly enough, it would seem stupid not to put serious effort into developing better ways of achieving negative emissions. But the better such R & D makes the outlook for negative emissions appear, the more the impetus for prompt emissions reduction diminishes. Something similar applies for a more radical potential response, solar geoengineering, which like the ping-pong balls of 1965 would reflect sunlight back to space before it could warm the Earth. Researchers thinking about this all stress that it should be used to reduce the harm of carbon dioxide already emitted, not used as an excuse to emit more. But the temptation would be there.

Even if the world were doing enough to limit warming to 2°C, there would still be a need for adaptation. Many communities are not even well adapted to today’s climate. Adaptation is in some ways a much easier policy to pursue than emissions reduction. But it has disadvantages. It gets harder as things get worse. It has a strong tendency to be reactive. And it is most easily achieved by those with resources; people who are marginalised and excluded, who the IPCC finds tend to be most affected by climate change, have the least capacity to adapt to it. It can also fall prey to the “moral hazard” problem encountered by negative emissions and solar geoengineering.

None of this means adaptation is not worthwhile. It is vital, and the developed nations—developed thanks to fossil fuels—have a duty to help their poorer counterparts achieve it, a duty acknowledged in Paris, if as yet barely acted on. But it will not stabilise the climate that humans have, in their global growth spurt, destabilised. And it will not stop all the suffering that instability will bring. ■

Sign up to our new fortnightly climate-change newsletter here

This article appeared in the Briefing section of the print edition under the headline “What goes up”

From the September 21st 2019 edition

Discover stories from this section and more in the list of contents

More from Briefing

The Chinese authorities are concealing the state of the economy

But the Communist Party’s internal information systems may also be flawed

“Hell on earth”: satellite images document the siege of a Sudanese city

El-Fasher, until recently a place of refuge, is under attack

The ripple effects of Sudan’s war are being felt across three continents

It is a sign of growing global impunity and disorder

Anarchy in Sudan has spawned the world’s worst famine in 40 years

Millions are likely to perish

Kamala Harris has revealed only the vaguest of policy platforms

Her record suggests she would be a pragmatist

Talent is scarce. Yet many countries spurn it

There is growing competition for the best and the brightest migrants

• ENVIRONMENT

How global warming is disrupting life on Earth

The signs of global warming are everywhere, and are more complex than just climbing temperatures.

Our planet is getting hotter. Since the Industrial Revolution—an event that spurred the use of fossil fuels in everything from power plants to transportation—Earth has warmed by 1 degree Celsius, about 2 degrees Fahrenheit.  

That may sound insignificant, but 2023 was the hottest year on record , and all 10 of the hottest years on record have occurred in the past decade.  

Global warming and climate change are often used interchangeably as synonyms, but scientists prefer to use “climate change” when describing the complex shifts now affecting our planet’s weather and climate systems.  

Climate change encompasses not only rising average temperatures but also natural disasters, shifting wildlife habitats, rising seas , and a range of other impacts. All of these changes are emerging as humans continue to add heat-trapping greenhouse gases , like carbon dioxide and methane, to the atmosphere.

What causes global warming?

When fossil fuel emissions are pumped into the atmosphere, they change the chemistry of our atmosphere, allowing sunlight to reach the Earth but preventing heat from being released into space. This keeps Earth warm, like a greenhouse, and this warming is known as the greenhouse effect .  

Carbon dioxide is the most commonly found greenhouse gas and about 75 percent of all the climate warming pollution in the atmosphere. This gas is a product of producing and burning oil, gas, and coal. About a quarter of Carbon dioxide also results from land cleared for timber or agriculture.  

Methane is another common greenhouse gas. Although it makes up only about 16 percent of emissions, it's roughly 25 times more potent than carbon dioxide and dissipates more quickly. That means methane can cause a large spark in warming, but ending methane pollution can also quickly limit the amount of atmospheric warming. Sources of this gas include agriculture (mostly livestock), leaks from oil and gas production, and waste from landfills.  

What are the effects of global warming?  

One of the most concerning impacts of global warming is the effect warmer temperatures will have on Earth's polar regions and mountain glaciers. The Arctic is warming four times faster than the rest of the planet. This warming reduces critical ice habitat and it disrupts the flow of the jet stream, creating more unpredictable weather patterns around the globe.  

( Learn more about the jet stream. )

A warmer planet doesn't just raise temperatures. Precipitation is becoming more extreme as the planet heats. For every degree your thermometer rises, the air holds about seven percent more moisture. This increase in moisture in the atmosphere can produce flash floods, more destructive hurricanes, and even paradoxically, stronger snow storms.  

The world's leading scientists regularly gather to review the latest research on how the planet is changing. The results of this review is synthesized in regularly published reports known as the Intergovernmental Panel on Climate Change (IPCC) reports.  

A recent report outlines how disruptive a global rise in temperature can be:

• Coral reefs are now a highly endangered ecosystem. When corals face environmental stress, such as high heat, they expel their colorful algae and turn a ghostly white, an effect known as coral bleaching . In this weakened state, they more easily die.  
• Trees are increasingly dying from drought , and this mass mortality is reshaping forest ecosystems.
• Rising temperatures and changing precipitation patterns are making wildfires more common and more widespread. Research shows they're even moving into the eastern U.S. where fires have historically been less common.
• Hurricanes are growing more destructive and dumping more rain, an effect that will result in more damage. Some scientists say we even need to be preparing for Cat 6 storms . (The current ranking system ends at Cat 5.)

How can we limit global warming?  

Limiting the rising in global warming is theoretically achievable, but politically, socially, and economically difficult.  

Those same sources of greenhouse gas emissions must be limited to reduce warming. For example, oil and gas used to generate electricity or power industrial manufacturing will need to be replaced by net zero emission technology like wind and solar power. Transportation, another major source of emissions, will need to integrate more electric vehicles, public transportation, and innovative urban design, such as safe bike lanes and walkable cities.  

( Learn more about solutions to limit global warming. )

One global warming solution that was once considered far fetched is now being taken more seriously: geoengineering. This type of technology relies on manipulating the Earth's atmosphere to physically block the warming rays of the sun or by sucking carbon dioxide straight out of the sky.

Restoring nature may also help limit warming. Trees, oceans, wetlands, and other ecosystems help absorb excess carbon—but when they're lost, so too is their potential to fight climate change.  

Ultimately, we'll need to adapt to warming temperatures, building homes to withstand sea level rise for example, or more efficiently cooling homes during heat waves.  

Related Topics

• CLIMATE CHANGE
• ENVIRONMENT AND CONSERVATION
• POLAR REGIONS

You May Also Like

Why all life on Earth depends on trees

Life probably exists beyond Earth. So how do we find it?

Pizzlies, grolars, and narlugas: Why we may soon see more Arctic hybrids

For Antarctica’s emperor penguins, ‘there is no time left’

Listen to 30 years of climate change transformed into haunting music

• Environment
• Paid Content

History & Culture

• History & Culture
• Mind, Body, Wonder
• Terms of Use
• Privacy Policy
• Your US State Privacy Rights
• Children's Online Privacy Policy
• Interest-Based Ads
• About Nielsen Measurement
• Do Not Sell or Share My Personal Information
• Nat Geo Home
• Attend a Live Event
• Book a Trip
• Inspire Your Kids
• Shop Nat Geo
• Visit the D.C. Museum
• Learn About Our Impact
• Support Our Mission
• Advertise With Us
• Customer Service
• Renew Subscription
• Manage Your Subscription
• Work at Nat Geo
• Sign Up for Our Newsletters
• Contribute to Protect the Planet

Copyright © 1996-2015 National Geographic Society Copyright © 2015-2024 National Geographic Partners, LLC. All rights reserved

What Are the Causes of Climate Change?

We can’t fight climate change without understanding what drives it.

Low water levels at Shasta Lake, California, following a historic drought in October 2021

Andrew Innerarity/California Department of Water Resources

• Share this page block

At the root of climate change is the phenomenon known as the greenhouse effect , the term scientists use to describe the way that certain atmospheric gases “trap” heat that would otherwise radiate upward, from the planet’s surface, into outer space. On the one hand, we have the greenhouse effect to thank for the presence of life on earth; without it, our planet would be cold and unlivable.

But beginning in the mid- to late-19th century, human activity began pushing the greenhouse effect to new levels. The result? A planet that’s warmer right now than at any other point in human history, and getting ever warmer. This global warming has, in turn, dramatically altered natural cycles and weather patterns, with impacts that include extreme heat, protracted drought, increased flooding, more intense storms, and rising sea levels. Taken together, these miserable and sometimes deadly effects are what have come to be known as climate change .

Detailing and discussing the human causes of climate change isn’t about shaming people, or trying to make them feel guilty for their choices. It’s about defining the problem so that we can arrive at effective solutions. And we must honestly address its origins—even though it can sometimes be difficult, or even uncomfortable, to do so. Human civilization has made extraordinary productivity leaps, some of which have led to our currently overheated planet. But by harnessing that same ability to innovate and attaching it to a renewed sense of shared responsibility, we can find ways to cool the planet down, fight climate change , and chart a course toward a more just, equitable, and sustainable future.

Here’s a rough breakdown of the factors that are driving climate change.

Natural causes of climate change

Human-driven causes of climate change, transportation, electricity generation, industry & manufacturing, agriculture, oil & gas development, deforestation, our lifestyle choices.

Some amount of climate change can be attributed to natural phenomena. Over the course of Earth’s existence, volcanic eruptions , fluctuations in solar radiation , tectonic shifts , and even small changes in our orbit have all had observable effects on planetary warming and cooling patterns.

But climate records are able to show that today’s global warming—particularly what has occured since the start of the industrial revolution—is happening much, much faster than ever before. According to NASA , “[t]hese natural causes are still in play today, but their influence is too small or they occur too slowly to explain the rapid warming seen in recent decades.” And the records refute the misinformation that natural causes are the main culprits behind climate change, as some in the fossil fuel industry and conservative think tanks would like us to believe.

Chemical manufacturing plants emit fumes along Onondaga Lake in Solvay, New York, in the late-19th century. Over time, industrial development severely polluted the local area.

Library of Congress, Prints & Photographs Division, Detroit Publishing Company Collection

Scientists agree that human activity is the primary driver of what we’re seeing now worldwide. (This type of climate change is sometimes referred to as anthropogenic , which is just a way of saying “caused by human beings.”) The unchecked burning of fossil fuels over the past 150 years has drastically increased the presence of atmospheric greenhouse gases, most notably carbon dioxide . At the same time, logging and development have led to the widespread destruction of forests, wetlands, and other carbon sinks —natural resources that store carbon dioxide and prevent it from being released into the atmosphere.

Right now, atmospheric concentrations of greenhouse gases like carbon dioxide, methane , and nitrous oxide are the highest they’ve been in the last 800,000 years . Some greenhouse gases, like hydrochlorofluorocarbons (HFCs) , do not even exist in nature. By continuously pumping these gases into the air, we helped raise the earth’s average temperature by about 1.9 degrees Fahrenheit during the 20th century—which has brought us to our current era of deadly, and increasingly routine, weather extremes. And it’s important to note that while climate change affects everyone in some way, it doesn’t do so equally: All over the world, people of color and those living in economically disadvantaged or politically marginalized communities bear a much larger burden , despite the fact that these communities play a much smaller role in warming the planet.

Our ways of generating power for electricity, heat, and transportation, our built environment and industries, our ways of interacting with the land, and our consumption habits together serve as the primary drivers of climate change. While the percentages of greenhouse gases stemming from each source may fluctuate, the sources themselves remain relatively consistent.

Traffic on Interstate 25 in Denver

David Parsons/iStock

The cars, trucks, ships, and planes that we use to transport ourselves and our goods are a major source of global greenhouse gas emissions. (In the United States, they actually constitute the single-largest source.) Burning petroleum-based fuel in combustion engines releases massive amounts of carbon dioxide into the atmosphere. Passenger cars account for 41 percent of those emissions, with the typical passenger vehicle emitting about 4.6 metric tons of carbon dioxide per year. And trucks are by far the worst polluters on the road. They run almost constantly and largely burn diesel fuel, which is why, despite accounting for just 4 percent of U.S. vehicles, trucks emit 23 percent of all greenhouse gas emissions from transportation.

We can get these numbers down, but we need large-scale investments to get more zero-emission vehicles on the road and increase access to reliable public transit .

As of 2021, nearly 60 percent of the electricity used in the United States comes from the burning of coal, natural gas , and other fossil fuels . Because of the electricity sector’s historical investment in these dirty energy sources, it accounts for roughly a quarter of U.S. greenhouse gas emissions, including carbon dioxide, methane, and nitrous oxide.

That history is undergoing a major change, however: As renewable energy sources like wind and solar become cheaper and easier to develop, utilities are turning to them more frequently. The percentage of clean, renewable energy is growing every year—and with that growth comes a corresponding decrease in pollutants.

But while things are moving in the right direction, they’re not moving fast enough. If we’re to keep the earth’s average temperature from rising more than 1.5 degrees Celsius, which scientists say we must do in order to avoid the very worst impacts of climate change, we have to take every available opportunity to speed up the shift from fossil fuels to renewables in the electricity sector.

The factories and facilities that produce our goods are significant sources of greenhouse gases; in 2020, they were responsible for fully 24 percent of U.S. emissions. Most industrial emissions come from the production of a small set of carbon-intensive products, including basic chemicals, iron and steel, cement and concrete, aluminum, glass, and paper. To manufacture the building blocks of our infrastructure and the vast array of products demanded by consumers, producers must burn through massive amounts of energy. In addition, older facilities in need of efficiency upgrades frequently leak these gases, along with other harmful forms of air pollution .

One way to reduce the industrial sector’s carbon footprint is to increase efficiency through improved technology and stronger enforcement of pollution regulations. Another way is to rethink our attitudes toward consumption (particularly when it comes to plastics ), recycling , and reuse —so that we don’t need to be producing so many things in the first place. And, since major infrastructure projects rely heavily on industries like cement manufacturing (responsible for 7 percent of annual global greenhouse gas), policy mandates must leverage the government’s purchasing power to grow markets for cleaner alternatives, and ensure that state and federal agencies procure more sustainably produced materials for these projects. Hastening the switch from fossil fuels to renewables will also go a long way toward cleaning up this energy-intensive sector.

The advent of modern, industrialized agriculture has significantly altered the vital but delicate relationship between soil and the climate—so much so that agriculture accounted for 11 percent of U.S. greenhouse gas emissions in 2020. This sector is especially notorious for giving off large amounts of nitrous oxide and methane, powerful gases that are highly effective at trapping heat. The widespread adoption of chemical fertilizers , combined with certain crop-management practices that prioritize high yields over soil health, means that agriculture accounts for nearly three-quarters of the nitrous oxide found in our atmosphere. Meanwhile, large-scale industrialized livestock production continues to be a significant source of atmospheric methane, which is emitted as a function of the digestive processes of cattle and other ruminants.

Stephen McComber holds a squash harvested from the community garden in Kahnawà:ke Mohawk Territory, a First Nations reserve of the Mohawks of Kahnawà:ke, in Quebec.

Stephanie Foden for NRDC

But farmers and ranchers—especially Indigenous farmers, who have been tending the land according to sustainable principles —are reminding us that there’s more than one way to feed the world. By adopting the philosophies and methods associated with regenerative agriculture , we can slash emissions from this sector while boosting our soil’s capacity for sequestering carbon from the atmosphere, and producing healthier foods.

A decades-old, plugged and abandoned oil well at a cattle ranch in Crane County, Texas, in June 2021, when it was found to be leaking brine water

Matthew Busch/Bloomberg via Getty Images

Oil and gas lead to emissions at every stage of their production and consumption—not only when they’re burned as fuel, but just as soon as we drill a hole in the ground to begin extracting them. Fossil fuel development is a major source of methane, which invariably leaks from oil and gas operations : drilling, fracking , transporting, and refining. And while methane isn’t as prevalent a greenhouse gas as carbon dioxide, it’s many times more potent at trapping heat during the first 20 years of its release into the atmosphere. Even abandoned and inoperative wells—sometimes known as “orphaned” wells —leak methane. More than 3 million of these old, defunct wells are spread across the country and were responsible for emitting more than 280,000 metric tons of methane in 2018.

Unsurprisingly, given how much time we spend inside of them, our buildings—both residential and commercial—emit a lot of greenhouse gases. Heating, cooling, cooking, running appliances, and maintaining other building-wide systems accounted for 13 percent of U.S. emissions overall in 2020. And even worse, some 30 percent of the energy used in U.S. buildings goes to waste, on average.

Every day, great strides are being made in energy efficiency , allowing us to achieve the same (or even better) results with less energy expended. By requiring all new buildings to employ the highest efficiency standards—and by retrofitting existing buildings with the most up-to-date technologies—we’ll reduce emissions in this sector while simultaneously making it easier and cheaper for people in all communities to heat, cool, and power their homes: a top goal of the environmental justice movement.

An aerial view of clearcut sections of boreal forest near Dryden in Northwestern Ontario, Canada, in June 2019

River Jordan for NRDC

Another way we’re injecting more greenhouse gas into the atmosphere is through the clearcutting of the world’s forests and the degradation of its wetlands . Vegetation and soil store carbon by keeping it at ground level or underground. Through logging and other forms of development, we’re cutting down or digging up vegetative biomass and releasing all of its stored carbon into the air. In Canada’s boreal forest alone, clearcutting is responsible for releasing more than 25 million metric tons of carbon dioxide into the atmosphere each year—the emissions equivalent of 5.5 million vehicles.

Government policies that emphasize sustainable practices, combined with shifts in consumer behavior , are needed to offset this dynamic and restore the planet’s carbon sinks .

The Yellow Line Metro train crossing over the Potomac River from Washington, DC, to Virginia on June 24, 2022

Sarah Baker

The decisions we make every day as individuals—which products we purchase, how much electricity we consume, how we get around, what we eat (and what we don’t—food waste makes up 4 percent of total U.S. greenhouse gas emissions)—add up to our single, unique carbon footprints . Put all of them together and you end up with humanity’s collective carbon footprint. The first step in reducing it is for us to acknowledge the uneven distribution of climate change’s causes and effects, and for those who bear the greatest responsibility for global greenhouse gas emissions to slash them without bringing further harm to those who are least responsible .

The big, climate-affecting decisions made by utilities, industries, and governments are shaped, in the end, by us : our needs, our demands, our priorities. Winning the fight against climate change will require us to rethink those needs, ramp up those demands , and reset those priorities. Short-term thinking of the sort that enriches corporations must give way to long-term planning that strengthens communities and secures the health and safety of all people. And our definition of climate advocacy must go beyond slogans and move, swiftly, into the realm of collective action—fueled by righteous anger, perhaps, but guided by faith in science and in our ability to change the world for the better.

If our activity has brought us to this dangerous point in human history, breaking old patterns can help us find a way out.

This NRDC.org story is available for online republication by news media outlets or nonprofits under these conditions: The writer(s) must be credited with a byline; you must note prominently that the story was originally published by NRDC.org and link to the original; the story cannot be edited (beyond simple things such as grammar); you can’t resell the story in any form or grant republishing rights to other outlets; you can’t republish our material wholesale or automatically—you need to select stories individually; you can’t republish the photos or graphics on our site without specific permission; you should drop us a note to let us know when you’ve used one of our stories.

We need climate action to be a top priority in Washington!

Tell President Biden and Congress to slash climate pollution and reduce our dependence on fossil fuels.

Urge President Biden and Congress to make equitable climate action a top priority

2023 was the hottest year on record, underscoring the urgency of shifting to clean energy and curbing the carbon pollution that is driving the climate crisis. President Biden and Congress have the tools to get the job done.

Related Stories

Greenhouse Effect 101

What Are the Solutions to Climate Change?

Failing to Meet Our Climate Goals Is Not an Option

When you sign up, you’ll become a member of NRDC’s Activist Network. We will keep you informed with the latest alerts and progress reports.

Climate Change: Evidence and Causes: Update 2020 (2020)

Chapter: conclusion, c onclusion.

This document explains that there are well-understood physical mechanisms by which changes in the amounts of greenhouse gases cause climate changes. It discusses the evidence that the concentrations of these gases in the atmosphere have increased and are still increasing rapidly, that climate change is occurring, and that most of the recent change is almost certainly due to emissions of greenhouse gases caused by human activities. Further climate change is inevitable; if emissions of greenhouse gases continue unabated, future changes will substantially exceed those that have occurred so far. There remains a range of estimates of the magnitude and regional expression of future change, but increases in the extremes of climate that can adversely affect natural ecosystems and human activities and infrastructure are expected.

Citizens and governments can choose among several options (or a mixture of those options) in response to this information: they can change their pattern of energy production and usage in order to limit emissions of greenhouse gases and hence the magnitude of climate changes; they can wait for changes to occur and accept the losses, damage, and suffering that arise; they can adapt to actual and expected changes as much as possible; or they can seek as yet unproven “geoengineering” solutions to counteract some of the climate changes that would otherwise occur. Each of these options has risks, attractions and costs, and what is actually done may be a mixture of these different options. Different nations and communities will vary in their vulnerability and their capacity to adapt. There is an important debate to be had about choices among these options, to decide what is best for each group or nation, and most importantly for the global population as a whole. The options have to be discussed at a global scale because in many cases those communities that are most vulnerable control few of the emissions, either past or future. Our description of the science of climate change, with both its facts and its uncertainties, is offered as a basis to inform that policy debate.

A CKNOWLEDGEMENTS

The following individuals served as the primary writing team for the 2014 and 2020 editions of this document:

• Eric Wolff FRS, (UK lead), University of Cambridge
• Inez Fung (NAS, US lead), University of California, Berkeley
• Brian Hoskins FRS, Grantham Institute for Climate Change
• John F.B. Mitchell FRS, UK Met Office
• Tim Palmer FRS, University of Oxford
• Benjamin Santer (NAS), Lawrence Livermore National Laboratory
• John Shepherd FRS, University of Southampton
• Keith Shine FRS, University of Reading.
• Susan Solomon (NAS), Massachusetts Institute of Technology
• Kevin Trenberth, National Center for Atmospheric Research
• John Walsh, University of Alaska, Fairbanks
• Don Wuebbles, University of Illinois

Staff support for the 2020 revision was provided by Richard Walker, Amanda Purcell, Nancy Huddleston, and Michael Hudson. We offer special thanks to Rebecca Lindsey and NOAA Climate.gov for providing data and figure updates.

The following individuals served as reviewers of the 2014 document in accordance with procedures approved by the Royal Society and the National Academy of Sciences:

• Richard Alley (NAS), Department of Geosciences, Pennsylvania State University
• Alec Broers FRS, Former President of the Royal Academy of Engineering
• Harry Elderfield FRS, Department of Earth Sciences, University of Cambridge
• Joanna Haigh FRS, Professor of Atmospheric Physics, Imperial College London
• Isaac Held (NAS), NOAA Geophysical Fluid Dynamics Laboratory
• John Kutzbach (NAS), Center for Climatic Research, University of Wisconsin
• Jerry Meehl, Senior Scientist, National Center for Atmospheric Research
• John Pendry FRS, Imperial College London
• John Pyle FRS, Department of Chemistry, University of Cambridge
• Gavin Schmidt, NASA Goddard Space Flight Center
• Emily Shuckburgh, British Antarctic Survey
• Gabrielle Walker, Journalist
• Andrew Watson FRS, University of East Anglia

The Support for the 2014 Edition was provided by NAS Endowment Funds. We offer sincere thanks to the Ralph J. and Carol M. Cicerone Endowment for NAS Missions for supporting the production of this 2020 Edition.

F OR FURTHER READING

For more detailed discussion of the topics addressed in this document (including references to the underlying original research), see:

• Intergovernmental Panel on Climate Change (IPCC), 2019: Special Report on the Ocean and Cryosphere in a Changing Climate [ https://www.ipcc.ch/srocc ]
• National Academies of Sciences, Engineering, and Medicine (NASEM), 2019: Negative Emissions Technologies and Reliable Sequestration: A Research Agenda [ https://www.nap.edu/catalog/25259 ]
• Royal Society, 2018: Greenhouse gas removal [ https://raeng.org.uk/greenhousegasremoval ]
• U.S. Global Change Research Program (USGCRP), 2018: Fourth National Climate Assessment Volume II: Impacts, Risks, and Adaptation in the United States [ https://nca2018.globalchange.gov ]
• IPCC, 2018: Global Warming of 1.5°C [ https://www.ipcc.ch/sr15 ]
• USGCRP, 2017: Fourth National Climate Assessment Volume I: Climate Science Special Reports [ https://science2017.globalchange.gov ]
• NASEM, 2016: Attribution of Extreme Weather Events in the Context of Climate Change [ https://www.nap.edu/catalog/21852 ]
• IPCC, 2013: Fifth Assessment Report (AR5) Working Group 1. Climate Change 2013: The Physical Science Basis [ https://www.ipcc.ch/report/ar5/wg1 ]
• NRC, 2013: Abrupt Impacts of Climate Change: Anticipating Surprises [ https://www.nap.edu/catalog/18373 ]
• NRC, 2011: Climate Stabilization Targets: Emissions, Concentrations, and Impacts Over Decades to Millennia [ https://www.nap.edu/catalog/12877 ]
• Royal Society 2010: Climate Change: A Summary of the Science [ https://royalsociety.org/topics-policy/publications/2010/climate-change-summary-science ]
• NRC, 2010: America’s Climate Choices: Advancing the Science of Climate Change [ https://www.nap.edu/catalog/12782 ]

Much of the original data underlying the scientific findings discussed here are available at:

• https://data.ucar.edu/
• https://climatedataguide.ucar.edu
• https://iridl.ldeo.columbia.edu
• https://ess-dive.lbl.gov/
• https://www.ncdc.noaa.gov/
• https://www.esrl.noaa.gov/gmd/ccgg/trends/
• http://scrippsco2.ucsd.edu
• http://hahana.soest.hawaii.edu/hot/

Climate change is one of the defining issues of our time. It is now more certain than ever, based on many lines of evidence, that humans are changing Earth's climate. The Royal Society and the US National Academy of Sciences, with their similar missions to promote the use of science to benefit society and to inform critical policy debates, produced the original Climate Change: Evidence and Causes in 2014. It was written and reviewed by a UK-US team of leading climate scientists. This new edition, prepared by the same author team, has been updated with the most recent climate data and scientific analyses, all of which reinforce our understanding of human-caused climate change.

Scientific information is a vital component for society to make informed decisions about how to reduce the magnitude of climate change and how to adapt to its impacts. This booklet serves as a key reference document for decision makers, policy makers, educators, and others seeking authoritative answers about the current state of climate-change science.

READ FREE ONLINE

Welcome to OpenBook!

You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

Do you want to take a quick tour of the OpenBook's features?

Show this book's table of contents , where you can jump to any chapter by name.

...or use these buttons to go back to the previous chapter or skip to the next one.

Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

Switch between the Original Pages , where you can read the report as it appeared in print, and Text Pages for the web version, where you can highlight and search the text.

To search the entire text of this book, type in your search term here and press Enter .

Share a link to this book page on your preferred social network or via email.

View our suggested citation for this chapter.

Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

Get Email Updates

Do you enjoy reading reports from the Academies online for free ? Sign up for email notifications and we'll let you know about new publications in your areas of interest when they're released.