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
Hotter, Weirder: How Climate Has Changed EarthLast Updated on 2014-12-03 11:46:22
In the more than two decades since world leaders first got together to try to solve global warming, life on Earth has changed, not just the climate. It's gotten hotter, more polluted with heat-trapping gases, more crowded and just downright wilder.
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Maryland set to allow frackingLast Updated on 2014-11-29 17:14:24Maryland officials have laid out a plan to permit hydraulic fracturing for natural gas in the western part of the state.
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Climate deal: What the scientists sayLast Updated on 2014-11-29 16:53:18
A snapshot of what scientists are saying about climate change ahead of the next round of UN talks opening in Lima on Monday.WHERE ARE WE NOW?
Atmospheric levels of three greenhouse gases from burning coal, oil and gas are the highest in 800,000 years.
Read more at: http://phys.org/news/2014-11-climate-scientists.html
Ecosystems and Human Well-Being: Volume 1: Current State and Trends: Air Quality and ClimateLast Updated on 2014-11-17 12:15:25
This is Chapter 13 of the Millenium Ecosystem Assessment report Ecosystems and Human Well-Being: Volume 1: Current State and Trends
Coordinating Lead Authors: Jo House, Victor Brovkin
Lead Authors: Richard Betts, Bob Constanza, Maria Assunçao Silva Dias, Beth Holland, Corinne Le Quéré, Nophea Kim Phat, Ulf Riebesell, Mary Scholes
Contributing Authors: Almut Arneth, Damian Barratt, Ken Cassman, Torben Christensen, Sarah Cornell, Jon Foley, Laurens Ganzeveld, Thomas Hickler, Sander Houweling, Marko Scholze, Fortunat Joos, Karen Kohfeld, Manfredi Manizza, Denis Ojima, I. Colin Prentice, Crystal Schaaf, Ben Smith, Ina Tegen, Kirsten Thonicke, Nicola Warwick
Review Editors: Pavel Kabat, Shuzo Nishioka
Ecosystems, both natural and managed, exert a strong influence on climate and air quality. Ecosystems are both sources and sinks of greenhouse gases,... More »
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