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&edu=high&dev=1/earth/Atmosphere/moons/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&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">computer models</a>, make different assumptions about how many <a href="/earth/climate/cli_greengas.html&edu=high&dev=1/earth/Atmosphere/moons/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>Although we humans have never experienced fast <a href="/earth/climate/climate.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">global warming</a>, our planet has. And our planet keeps records of what happened. The oldest records that the <a href="/earth/earth.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">Earth</a> keeps are in its <a href="/earth/geology/sed_intro.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">rocks</a>. In this image, <a href="/headline_universe/olpa/methane_28may08.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">geologists Chris von der Borch and Dave Mrofka</a> collect sediment samples in South Australia. These rocks hold clues to help explain why climate changed abruptly 635 million years ago.<p><small><em> Courtesy of Martin Kennedy, UCR</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&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">nitrogen oxides</a>, <a href="/earth/Atmosphere/vocs.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">VOCs</a>, <a href="/physical_science/chemistry/carbon_monoxide.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">carbon monoxide</a>, <a href="/physical_science/chemistry/carbon_dioxide.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">carbon dioxide</a>, <a href="/physical_science/chemistry/sulfur_oxides.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">sulfur dioxide</a> and <a href="/earth/Atmosphere/particulates.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">particulates</a>. Some of these gases are <a href="/earth/climate/cli_greengas.html&edu=high&dev=1/earth/Atmosphere/moons/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&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">greenhouse effect</a>.<p><small><em>Image copyright UCAR</em></small></p>As temperatures rise and soil moisture decreases, plants are stressed, which can lead to <a href="/earth/climate/crops_withering.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">crop withering</a>. <a href="/teacher_resources/online_courses/health/events_health.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">Droughts</a> accompanied by increased temperatures can lead to famine, social and political disruptions. Scientists are helping with early identification of drought that might trigger food shortages. Watch the NBC Learn video - <a href="/earth/changing_planet/withering_crops_intro.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">Changing Planet: Withering Crops</a> to find out more.<p><small><em>Image taken by Tomas Castelazo, Creative Commons <a href=&quot;http://creativecommons.org/licenses/by/3.0/deed.en&quot;>Attribution 3.0 Unported</a> license.</em></small></p>Scientists are concerned that melting Arctic sea ice will increase the amount of fresh water in the <a href="/earth/polar/arctic_currents.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">Beaufort Gyre</a>, which could spill out into the Atlantic and cause major climate shifts in North America and Western Europe. Watch the <a href="/earth/changing_planet/freshwater_arctic.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">Changing Planet: Fresh Water in the Arctic video</a>.<p><small><em> Courtesy of Jack Cook, WHOI (<a href="http://www.whoi.edu">Woods Hole Oceanographic Institute</a>)</em></small></p>How did life evolve on <a href="/earth/earth.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">Earth</a> during the <a href="/earth/past/Archean.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">Archean</a>, when the <a href="/sun/sun.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">Sun</a> was about 25% weaker than today? The Earth should have been <a href="/earth/polar/cryosphere_glacier1.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">glaciated</a>, if <a href="/earth/climate/earth_greenhouse.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">greenhouse</a> gas concentration was the same as today. <a href="http://www.manchester.ac.uk/aboutus/news/display/?id=10798">Researchers</a> studying the <a href="/physical_science/physics/atom_particle/isotope.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">isotopic</a> signatures of Earth's early atmosphere in <a href="/earth/geology/rocks_intro.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">rocks</a> from Northern Australia have ruled out high levels of <a href="/physical_science/chemistry/nitrogen_molecular.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">nitrogen</a> as a possible way to increase warming from <a href="/earth/Atmosphere/overview.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">atmospheric</a> <a href="/physical_science/chemistry/carbon_dioxide.html&edu=high&dev=1/earth/Atmosphere/moons/cloudart_present.ppsx">carbon dioxide</a>.<p><small><em>Image courtesy of Manchester University</em></small></p>

Explore Climate and Global Change

What Is Climate?

Climate in your place on the globe is called regional climate. It is the average weather pattern ...Read more

What Controls the Climate System?

A factor that has an affect on climate is called a “forcing.” Some forcings, like volcanic ...Read more

Climates of the Past (Paleoclimates)

Climate change has affected the Earth throughout its 4.6 billion year history. The Earth has ...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

The world's surface air temperature increased an average of 0.6° Celsius (1.1°F) during the ...Read more

Climate Change in Polar Regions

The effects of climate change are not felt with the same intensity in all parts of the world. ...Read more

El Nino and Other Climate Events

Sometimes there is a disruption in Earth’s climate system that might last a few weeks or a ...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 quickly and human activities are mostly to blame.  By releasing ...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?

Magnetic polarity reversal
xMagnetic polarity reversal : A magnetic polarity reversal is a change of the earth's magnetic field to the opposite polarity. This has occurred at irregular intervals during geologic time.

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Research Highlights

Gulf Oil Spill: Mississippi River Hydrology May Help Reduce Oil Onshore

The Gulf of Mexico: what role will the Mississippi River play in oil washing ashore and into delta wetlands? One of the spill's greatest environmental threats is to Louisiana's wetlands, scientists believe....Read more


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