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Science, Evolution, and Creationism, by the National Academies, focuses on teaching evolution in today's classrooms. Check out the other publications in our online store.

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">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">computer models</a>, make different
  assumptions about how many <a
  href="/earth/climate/cli_greengas.html&edu=high">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&edu=high">sea ice</a>, <a
  href="/earth/polar/polar_bears_jan07.html&edu=high">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&edu=high">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&edu=high">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>Scientists at the University of Michigan have found that <a href="/earth/polar/cryosphere_permafrost1.html&edu=high">permafrost</a> in the <a href="/earth/polar/polar_north.html&edu=high">Arctic</a> is extremely sensitive to sunlight.  Exposure to sunlight releases carbon gases trapped in the permafrost, including <a href="/earth/climate/earth_greenhouse.html&edu=high">climate-warming</a> <a href="/physical_science/chemistry/carbon_dioxide.html&edu=high">carbon dioxide</a>, to the <a href="/earth/Atmosphere/overview.html&edu=high">atmosphere</a> much faster than previously thought.<p><small><em>George Kling, The University of Michigan</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>Greenland's <a href="http://www.windows2universe.org/earth/polar/cryosphere_glacier1.html">ice sheet</a> saw a record <a href="http://www.windows2universe.org/headline_universe/olpa/greenland_10dec07.html">melt</a> in July 2012.  Scientists studying this event have found that this melting event was triggered by an influx of unusually warm air and amplified by the presence of a blanket of thin low-level <a href="http://www.windows2universe.org/earth/Atmosphere/cloud.html">clouds</a> which pushed temperatures up above freezing.  For more information see the <a href="http://www.news.wisc.edu/21638">press release</a> from the University of Wisconsin Madison.<p><small><em>Image courtesy of University of Wisconsin-Madison</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">crop withering</a>. <a href="/teacher_resources/online_courses/health/events_health.html&edu=high">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">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>

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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