Climate and Global Change

Warm near the equator and cold at the poles, our planet is able to support a variety of living things because of its diverse regional climates. The average of all these regions makes up Earth's global climate. Climate has cooled and warmed throughout Earth history for various reasons. Rapid warming like we see today is unusual in the history of our planet. The scientific consensus is that climate is warming as a result of the addition of heat-trapping greenhouse gases which are increasing dramatically in the atmosphere as a result of human activities.

Earth's global average surface <a href="/earth/climate/ipcc_feb2007.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">warming</a> relative to the 1980-1999 average over the past 100 years is shown in the black line. Predictions of the amount of warming in the future are shown by the red, green, and purple lines. These predictions, developed with <a href="/earth/climate/cli_models.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">computer models</a>, make different assumptions about how many <a href="/earth/climate/cli_greengas.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">greenhouse gases</a> we release into the atmosphere in the future.<p><small><em> A Windows to the Universe image based on a graph from the IPCC 4th Assessment Report</em></small></p>Roaming across Arctic <a href="/earth/polar/sea_ice.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">sea ice</a>, <a href="/earth/polar/polar_bears_jan07.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">polar bears</a> peer through cracks in the ice to look for ringed seals, their favorite food, in the water below. Almost all of a polar bear's food comes from the sea. The <a href="/earth/polar/sea_ice.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">floating sea ice</a> is a perfect vantage point for the bears as they hunt for food. Unfortunately, the amount of sea ice floating in the <a href="/earth/polar/polar_north.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">Arctic region</a> is shrinking each year, and getting farther apart.<p><small><em>Image courtesy of Ansgar Walk. Creative Commons Attribution-Share Alike 2.5 Generic license.</em></small></p><a href="/earth/polar/cryosphere_permafrost1.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">Permafrost</a> is ground that is below the freezing point of water (0C or 32F) for two or more years. Permafrost is found at high latitudes like the <a href="/earth/polar/polar_north.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">Arctic</a> and <a href="/earth/polar/polar_south.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">Antarctic</a>. It is also common at high altitudes - like mountainous areas wherever the <a href="/earth/climate/cli_define.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">climate</a> is cold. Permafrost has been thawing relatively quickly in recent years. Scientists have found that the rate of permafrost thaw has increased because of <a href="/earth/climate/cli_effects.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">global warming</a>.<p><small><em>Image courtesy of the USGS</em></small></p>Coral animals build reefs in warm, tropical seawater. However, <a href="/earth/changing_planet/ocean_temperatures_intro.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">seawater can be too warm</a> for their liking. If waters get too warm, coral animals lose the algae that live within their little bodies, a process called coral bleaching. Without the algae, corals have less nutrition. Unless cooler temperatures return, allowing algae to return, the coral dies.<p><small><em>Credit: UNC</em></small></p>Many forms of air pollution are human-made. Industrial plants, power plants and vehicles with internal combustion engines produce <a href="/earth/climate/nitrogen_airpollution.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">nitrogen oxides</a>, <a href="/earth/Atmosphere/vocs.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">VOCs</a>, <a href="/physical_science/chemistry/carbon_monoxide.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">carbon monoxide</a>, <a href="/physical_science/chemistry/carbon_dioxide.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">carbon dioxide</a>, <a href="/physical_science/chemistry/sulfur_oxides.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">sulfur dioxide</a> and <a href="/earth/Atmosphere/particulates.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">particulates</a>. Some of these gases are <a href="/earth/climate/cli_greengas.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">greenhouse gases</a>, meaning that they retain heat in the Earth's atmosphere, due to the Earth's <a href="/earth/climate/earth_greenhouse.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">greenhouse effect</a>.<p><small><em>Image copyright UCAR</em></small></p><b><i>Looking for online resources about climate and climate change for your classroom?</i></b> Windows to the Universe is a free interlinked learning ecosystem to a wealth of resources on our site and elsewhere that support you on these topics, including <a href="/teacher_resources/climate_change_course.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">course readings</a>, <a href="/php/teacher_resources/activity.php#6">classroom activities and presentations</a>, and online interactives. Our <a href="/teacher_resources/climate.html&dev=1/earth/Atmosphere/moons/h/neptune/cloudart_present.ppsx">Climate Change Education Resources page</a> provides links to content you can use right away in the classroom!<p><small><em> Ute Kaden/PolarTREC</em></small></p>

Explore Climate and Global Change

What Is Climate?

The climate where you live is called regional climate. It is the average weather in a place ...Read more

What Controls the Climate System?

Some of the factors that have an affect on climate, like volcanic eruptions and changes in ...Read more

Climates of the Past (Paleoclimates)

Earth's climate has been changing for billions of years. It warmed and cooled many times long ...Read more

Our Changing Planet

Our planet is changing rapidly. Check out videos and lesson plans for key climate change indicators ...Read more

Effects of Climate Change Today

Over 100 years ago, people worldwide began burning more coal and oil for homes, factories, ...Read more

Climate Change in Polar Regions

The effects of climate change are not the same in all parts of the world. While Earth’s average ...Read more

El Nino and Other Climate Events

Sometimes there is a change in the way air moves through parts of the atmosphere. And there ...Read more

The Role of Clouds in Climate

Clouds are an important part of Earth's weather and climate. Scientists use computer models ...Read more

Energy Choices and Climate Change

The choices we make about the sources of the energy we use and the amount of energy we use affect ...Read more

The Intergovernmental Panel on Climate Change

The IPCC is a group of hundreds of experts from more than 100 countries ...Read more

Tackling the Global Warming Challenge

Earth’s climate is warming and we humans are mostly to blame.  By releasing greenhouse gases ...Read more

More about Climate and Global Change

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Did you know?

Did you know that a significant portion of sea level rise is due to the expansion of sea water due to increasing temperature?

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Earth and Space Science Concept of the Day

Do you know what this word or phrase means?

Alluvium
xAlluvium : Alluvium is loose gravel, sand, silt, or clay deposited by streams.

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Research Highlights

Deadly Tonga Earthquake Revealed as Three Big Quakes

Geologists have learned that a magnitude-8.1 earthquake and tsunami that killed 192 people on September 29, 2009 in Samoa, American Samoa and Tonga was in fact a triple-whammy. The 8.1 "great earthquake"...Read more


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