Runaway greenhouse effect
From Conservapedia
A runaway greenhouse effect has been predicted by some climate scientists, in which slight increases in trace gases in the Earth's atmosphere would lead to higher air temperatures. These higher temperatures would in turn cause "greenhouse gases" such as carbon dioxide to have higher concentrations, which in turn would accelerate the warming trend. Alarming increases of 3 to 15 degrees Fahrenheit have been predicted.
Outside of the political sphere, few academics give any credence to this theory.
MIT professor Richard Lindzen wrote:
- It is still of interest to ask what we would expect a doubling of carbon dioxide to do. A large number of calculations show that if this is all that happened, we might expect a warming of from .5 to 1.2 degrees centigrade. The general consensus is that such warming would present few, if any, problems. ... current models depend heavily on undemonstrated positive feedback factors to predict high levels of warming.[1]
Another professor wrote:
- Computer models suggest that a doubling of the concentration of the main greenhouse gas, carbon dioxide, may raise the average global temperature between 1 and 3° Celsius. However, the numeric equations of computer models do not accurately simulate the effects of a number of possible negative feedbacks. For example, many of the models cannot properly simulate the negative effects that increased cloud cover would have on the radiation balance of a warmer Earth. Increasing the Earth's temperature would cause the oceans to evaporate greater amounts of water, causing the atmosphere to become cloudier. These extra clouds would then reflect a greater proportion of the Sun's energy back to space reducing the amount of solar radiation absorbed by the atmosphere and the Earth's surface. With less solar energy being absorbed at the surface, the effects of an enhanced greenhouse effect may be counteracted.[2]
Some scientists have tried to use Venus as an example of a planet where a runaway greenhouse effect has already occurred. However, Venus has many differences with Earth, including a lack of plate tectonics which make the comparison faulty.
See also
- Sea surface temperature (SST) - anomalies throughout the global climate system
