On earth, two elements, nitrogen () and oxygen (), make up almost 99% of the volume of clean, dry air. Most of the remaining 1% is accounted for by the inert gaseous element, argon (Ar). Argon and the tiny percentage of remaining gases are referred to as trace gases.
Certain trace atmospheric gases help to heat up our planet because they appear transparent to incoming visible (shortwave) light but act as a barrier to outgoing infrared (longwave) radiation. These special trace gases are often referred to as "greenhouse gases" because a scientist in the early 19th century suggested that they function much like the glass plates found on a greenhouse used for growing plants.
The earth's atmosphere is composed of gases (for example, and ) of just the right types and in just the right amounts to warm the earth to temperatures suitable for life. The effect of the atmosphere to trap heat is the true "greenhouse effect."
We can evaluate the effect of greenhouse gases by comparing Earth with its nearest planetary neighbors, Venus and Mars. These planets either have too much greenhouse effect or too little to be able to sustain life as we know it. The differences between the three planets have been termed the "Goldilocks Principle" (Venus is too hot, Mars is too cold, but Earth is just right). http://www.ucar.edu/learn/1_1_2_1t.htm
In this lesson, students learn how atmospheric composition and circulation impact the generation of storms. Students examine the primary and variable gases that...
Module: Amazon Rain Forest and Climate Change - UCAR COMETLast Updated on 2015-09-09 12:20:40
This module was developed by COMET - UCAR, Publish Date: 2009-12-22
English (text version), Portuguese (multimedia version)
Skill Level: Upper High School and Undergraduate
Completion Time: 1.50 - 2.00 hours
Includes Audio: no
Required Plugins: Flash
Requires sign in
Topics: Climate, Environment and Society
This module discusses global climate change that is occurring largely because of greenhouse gases emitted by human activities, and in particular the impact that tropical deforestation plays in the climate system. It also covers signs of climate change, the current thinking on future changes, and international agreements that are attempting to minimize the effects of climate change. The United Nations Collaborative Programme on Reducing Emissions from Deforestation and Forest Degradation in Developing Countries (UN-REDD Programme) is also discussed.
1. List factors... More »
Video: What We Known For Sure - Climate CentralLast Updated on 2015-09-09 12:08:02
2 min 20 sec
Today, about one in four molecules of carbon dioxide in the atmosphere come from human activity, mainly burning fossil fuels. We also know that carbon dioxide, or CO2, is a "greenhouse gas" — it traps extra energy from the sun and warms the earth. Carbon dioxide levels in the air have been increasing every year, and usually faster each year, as we burn more and more coal, oil and gas. These are scientific facts beyond any dispute. But before Charles David Keeling started daily measurements of atmospheric CO2 in 1958, from near the top of Mauna Loa volcano on Hawaii's Big Island, no one knew for sure about this growth.
Keeling's measurements showed not only an increase in carbon dioxide, but also a human fingerprint. The instrument he used — a spectrometer — is able to chemically tell apart the kind of carbon found in... More »
Speed Science Fact Sheets: Climate and Climate Change - CSCAPLast Updated on 2015-07-07 11:36:30
The Speed Science Fact Sheets and presentation videos are approved for use in educational, research and extension settings. The fact sheets were developed and presented as "Speed Science" by the Climate and Corn-based Cropping Systems CAP (CSCAP).
The CSCAP is a transdisciplinary partnership among 11 institutions creating new science and educational opportunities. It seeks to increase resilience and adaptability of Midwest agriculture to more volatile weather patterns by identifying farmer practices and policies that increase sustainability while meeting crop demand.
Printable flyer >> About CSCAP Project
To promote the long-term sustainability and productivity of U.S. corn-based cropping systems against recent climate trends and future uncertainty.
Develop standardized methodologies and perform baseline monitoring of carbon,... More »
State of the Climate in 2011Last Updated on 2015-05-09 14:34:12Worldwide, 2011 was the coolest year on record since 2008, yet temperatures remained above the 30 year average, according to the 2011 State of the Climate report released online by the National Oceanic and Atmospheric Administration (NOAA).
Back-to-back La Niñas cooled globe and
influenced extreme weather in 2011
The lead character of the 2011 climate story was a double dip La Niña, which chilled the Pacific at the start and end of the year. Many of the 2011 seasonal climate patterns around the world were consistent with common side effects of La Niña. More information.
Worldwide, 2011 was the coolest year on record since 2008, yet temperatures remained above the 30 year average, according to the 2011 State of the Climate report released online today by NOAA. The peer-reviewed report, issued in coordination with the American Meteorological Society (AMS), was... More »
No, climate models aren’t exaggerating global warmingLast Updated on 2015-02-06 11:01:05Weather and climate agencies around the world have been almost unanimous in declaring 2014 the hottest year on record — something that has promoted considerable chagrin among climate change doubters. That’s because these “skeptics” have long sought to cast doubt on man-made global warming by pointing to an alleged global warming “pause” or “slowdown” — going on to suggest that the computerized climate models that scientists use to project future temperatures are flawed, and overestimate carbon dioxide’s warming effect.
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