Global "Warning"

[srmom]

Just because a planet is closer to the sun does not necessarily make it warmer

Actually, this is incorrect, according to astrophysicists, Mercury (the closest planet to the sun) and Venus (2nd closest) are the hottest planets and it is because of their proximity to the sun.

Venus is thought to be the hottest planet, and one theory espoused by many scientists is that Venus, being closer to the sun, was subjected to a so-called runaway greenhouse effect, which caused any oceans to evaporate into the atmosphere.

Many scientists hold that:

only small changes in the atmospheric levels of water, in the form of vapour and ice crystals can contribute to significant changes to the temperature of the earth's surface, which far outweighs the effects of carbon dioxide and other gases released by human activities. Just a rise of 1% of water vapour could raise the global average temperature of Earth's surface more then 4 degrees Celsius.

The role of water vapour in controlling our planet's temperature was hinted at almost 150 years ago by Irish scientist John Tyndall. Tyndall, who also provided an explanation as to why the sky is blue, explained the problem: "The strongest radiant heat absorber, is the most important gas controlling Earth's temperature. Without water vapour, he wrote, the Earth's surface would be 'held fast in the iron grip of frost'." Thin clouds at high altitude allow sunlight to reach the earth's surface, but reflect back radiated heat, acting as an insulating greenhouse layer.

Water vapour levels are even less within our control than CO2 levels. According to Andrew E. Dessler of the Texas A & M University writing in 'The Science and Politics of Global Climate Change', "Human activities do not control all greenhouse gases, however. The most powerful greenhouse gas in the atmosphere is water vapour, he says, "Human activities have little direct control over its atmospheric abundance, which is controlled instead by the worldwide balance between evaporation from the oceans and precipitation."