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=elem">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=elem">computer models</a>, make different
  assumptions about how many <a
  href="/earth/climate/cli_greengas.html&edu=elem">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><a href="/earth/polar/cryosphere_permafrost1.html&edu=elem">Permafrost</a> is
ground that is below the freezing point of water (0°C or 32°F) for two
or more years. Permafrost is found at high latitudes like the
<a href="/earth/polar/polar_north.html&edu=elem">Arctic</a> and
<a href="/earth/polar/polar_south.html&edu=elem">Antarctic</a>.
It is also common at high altitudes - like mountainous areas wherever the
<a href="/earth/climate/cli_define.html&edu=elem">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&edu=elem">global
warming</a>.<p><small><em>Image courtesy of the    USGS</em></small></p><a href="/earth/climate/cli_define.html&edu=elem">Regional climate</a> is
the average weather pattern in a place over more than thirty years,
including the variations in
<a href="/earth/climate/cli_seasons.html&edu=elem">seasons</a>.
The climate of a region depends on many factors including sunlight,
altitude, topography, and proximity to oceans. Since the equatorial regions
receive more sunlight than the poles, climate varies with
<a href="/earth/climate/cli_latitude.html&edu=elem">latitude</a>.
This image shows how sea surface temperatures change at different latitudes.<p><small><em>Image courtesy of NOAA.  Public domain.</em></small></p>How did life evolve on <a href="/earth/earth.html&edu=elem">Earth</a> during the <a href="/earth/past/Archean.html&edu=elem">Archean</a>, when the <a href="/sun/sun.html&edu=elem">Sun</a> was about 25% weaker than today?  The Earth should have been <a href="/earth/polar/cryosphere_glacier1.html&edu=elem">glaciated</a>, if <a href="/earth/climate/earth_greenhouse.html&edu=elem">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=elem">isotopic</a> signatures of Earth's early atmosphere in <a href="/earth/geology/rocks_intro.html&edu=elem">rocks</a> from Northern Australia have ruled out high levels of <a href="/physical_science/chemistry/nitrogen_molecular.html&edu=elem">nitrogen</a> as a possible way to increase warming from <a href="/earth/Atmosphere/overview.html&edu=elem">atmospheric</a> <a href="/physical_science/chemistry/carbon_dioxide.html&edu=elem">carbon dioxide</a>.<p><small><em>Image courtesy of Manchester University</em></small></p>A <a href="http://iopscience.iop.org/1748-9326/8/2/024035/article">study</a> of over 40,000 written entries in Irish Annals and ice core measurements shows a strong correlation between <a href="http://www.windows2universe.org/earth/interior/eruptions.html">volcanic eruptions</a> and extreme cold weather in Ireland over a 1200 year period, from 431 to 1649.  During this time up to 48 volcanic eruptions were identified in Greenland ice core records through deposition of volcanic sulfate in annual layers of ice. Find out more about <a href="http://www.windows2universe.org/earth/climate/geosphere_volcanoes_influence_on_climate.html">volcanoes and climate</a>.<p><small><em>Image Courtesy of Marco Fulle</em></small></p><b><i>Looking for online resources to use in support of climate change education?</i></b>  Our <a href="/teacher_resources/climate.html&edu=elem">Climate Change Educator Resources page</a> provides links to online content, classroom activities, interactives, and videos as well as resources provided by other leading organizations and agencies on this topic.  Our <a href="/teacher_resources/climate_change_course.html&edu=elem">Climate Change Course Content page</a> provides links to online content for a range of climate change associated topics.<p><small><em>Image courtesy of   Mila Zinkova, Creative Commons Attribution ShareAlike license</em></small></p>

Windows to the Universe Community

News

Opportunities


Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA