Water vapor is also the most important greenhouse gas in the atmosphere. Heat radiated from Earth's surface is absorbed by water vapor molecules in the lower atmosphere. The water vapor molecules, in turn, radiate heat in all directions. Some of the heat returns to the Earth's surface.
Water vapor, CO2, methane and N2O are greenhouse gases because they are able to absorb most of the Earth's emitted longwave infrared radiation, which heats the atmosphere. Other atmospheric gases (such as N2 and O2) do not interact with longwave radiation, and therefore have no consequence for the greenhouse effect.
Greenhouse gases are gases that absorb and emit infrared radiation trapping heat in the atmosphere making it warmer than it should be. The ozone layer is depleted hence cannot absorb the infrared rays. Examples are methane, Carbon dioxide.
Why is water so important for controlling Earth's climate? Water vapor is one of the greenhouse gases that help trap heat. The water in oceans and lakes stores the energy radiated by the sun and releases it slowly. Water can absorb and store a lot of energy while only warming up by a few degrees.
Which gas then is to blame for global warming and should be controlled? Water vapor accounts for 60-70% of the greenhouse effect while CO2 accounts for 25% —a notable difference when numbers alone are compared.
It totally disregards the long-known fact that about 95% of all 'greenhouse' gases is WATER VAPOR!
The bottom three pie graphs show the breakdown for each of three greenhouse gases in comparison to the total. Seventy two percent (72%) of the total greenhouse gases emitted was carbon dioxide, 18% methane and 9% nitrous oxide.
The Short Answer: Carbon is in carbon dioxide, which is a greenhouse gas that works to trap heat close to Earth. It helps Earth hold the energy it receives from the Sun so it doesn't all escape back into space. If it weren't for carbon dioxide, Earth's ocean would be frozen solid.
Earth's greenhouse gases trap heat in the atmosphere and warm the planet. The main gases responsible for the greenhouse effect include carbon dioxide, methane, nitrous oxide, and water vapor (which all occur naturally), and fluorinated gases (which are synthetic).
Water vapor appears to cause the most important positive feedback. As the earth warms, the rate of evaporation and the amount of water vapor in the air both increase. Because water vapor is a greenhouse gas, this leads to further warming.
Explanation: Carbon-dioxide , methane and water vapor are green house gases , these gases absorb a large proportion of sunlight been reflected by the surface of the Earth . These absorption of sunlight leads to gradual increase in the annual temperature of the Earth . This phenomenon is known as greenhouse effect .
If there will be no water vapour then the crucial process of formation of clouds and then precipitation or rainfall will not occur. If there would be no water droplets or vapors in the air then the rain will become a faraway thing. Hence there would be no lakes, seas, or any pond on earth.