Background on Climate Change
"if carbon dioxide continues to increase, [we find] no reason to doubt that climate changes will result and no reason to believe that these changes will be negligible."
Source: National Academy of Science, Carbon Dioxide and Climate (Charney Report), Washington, D.C., 1979, p. vii.
"global warming has reached a level such that we can ascribe with a high degree of confidence a cause and effect relationship between the greenhouse effect and the observed warming."
Source: U.S. Senate, Committee on Energy and Natural Resources", Greenhouse Effect and Global Climate Change, part 2" 100th Cong., 1st sess., 23 June 1988, p. 44.
The Greenhouse effect is "a general warming effect felt on Earth’s surface, produced by greenhouse gases. These gases allow incoming solar radiation to pass through the Earth's atmosphere, but trap heat by preventing some of the infrared radiation from the Earth’s surface from escaping to outer space. This process occurs naturally and has kept the Earth's temperature about 60 degrees Fahrenheit warmer than it would otherwise be. Current life on Earth could not be sustained without the natural greenhouse effect. However, the greenhouse effect is becoming stronger as a result of human activities, which is causing the warming we have observed over the past century."
Source: EPA Glossary
"An increase in the natural process of the greenhouse effect, brought about by human activities, whereby greenhouse gases such as carbon dioxide, methane, chlorofluorocarbons and nitrous oxide are being released into the atmosphere at a far greater rate than would occur through natural processes and thus their concentrations are increasing. Also called anthropogenic greenhouse effect or climate change."
Source: NOVA Science in the News - Glossary, Australian Academy of Science
historical atmospheric carbon dioxide change
"CO2 is produced by fossil fuel burning and other activities such as industrial production and tropical deforestation. Measurements of CO2 from the Mauna Loa observatory show that concentrations have increased from about 313 ppm in 1960 to about 389 ppm in 2010. The effect of combustion-produced carbon dioxide on the global climate, a special case of the greenhouse effect first described in 1896 by Svante Arrhenius, has also been called the Callendar effect. Because it is a greenhouse gas, elevated CO2 levels contribute to additional absorption and emission of thermal infrared in the atmosphere, which produce net warming. According to the latest Assessment Report from the Intergovernmental Panel on Climate Change, "most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations".
Source: Hileman B (2005-11-28). "Ice Core Record Extended". Chemical & Engineering News 83 (48): 7.
The diagram below shows the history of atmospheric carbon dioxide from 800,000 years before present
Source: NOAA, Carbon Tracker, 2011
Global Mean Temperature Changes
Over the past decades, a continuing increase in global mean temperatures was measured.
Source: NASA, Goddard Institute for Space Studies, 2011
Further General Information on Climate Change
There is plenty of background information available that can give further information on the phenomenon termed as climate change. Please find related information in our resource centre here.