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Young Voices for the Planet DVD in our online store includes 8 films where students speak out and take action on climate change.

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.

<a href="/earth/polar/cryosphere_permafrost1.html">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">Arctic</a> and
<a href="/earth/polar/polar_south.html">Antarctic</a>.
It is also common at high altitudes - like mountainous areas wherever the
<a href="/earth/climate/cli_define.html">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">global
warming</a>.<p><small><em>Image courtesy of the    USGS</em></small></p>Although we humans have never experienced fast <a href="/earth/climate/climate.html">global
warming</a>, our
planet has. And our planet keeps records of what happened. The oldest
records that the
<a href="/earth/earth.html">Earth</a> keeps
are in its
<a href="/earth/geology/sed_intro.html">rocks</a>.
In this image, <a href="/headline_universe/olpa/methane_28may08.html">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><a href="/earth/climate/cli_define.html">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">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">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>Coral animals build reefs in warm, tropical seawater. However, <a href="/earth/changing_planet/ocean_temperatures_intro.html">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">nitrogen
oxides</a>,
<a href="/earth/Atmosphere/vocs.html">VOCs</a>,
<a href="/physical_science/chemistry/carbon_monoxide.html">carbon monoxide</a>,
<a href="/physical_science/chemistry/carbon_dioxide.html">carbon dioxide</a>,
<a href="/physical_science/chemistry/sulfur_oxides.html">sulfur dioxide</a> and
<a href="/earth/Atmosphere/particulates.html">particulates</a>.
Some of these gases are <a href="/earth/climate/cli_greengas.html">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">greenhouse effect</a>.<p><small><em>Image copyright UCAR</em></small></p>How did life evolve on <a href="/earth/earth.html">Earth</a> during the <a href="/earth/past/Archean.html">Archean</a>, when the <a href="/sun/sun.html">Sun</a> was about 25% weaker than today?  The Earth should have been <a href="/earth/polar/cryosphere_glacier1.html">glaciated</a>, if <a href="/earth/climate/earth_greenhouse.html">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">isotopic</a> signatures of Earth's early atmosphere in <a href="/earth/geology/rocks_intro.html">rocks</a> from Northern Australia have ruled out high levels of <a href="/physical_science/chemistry/nitrogen_molecular.html">nitrogen</a> as a possible way to increase warming from <a href="/earth/Atmosphere/overview.html">atmospheric</a> <a href="/physical_science/chemistry/carbon_dioxide.html">carbon dioxide</a>.<p><small><em>Image courtesy of Manchester University</em></small></p>

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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