Why is water vapor not considered to be a greenhouse gas?

Answer 1

It is not possible to regulate water vapor as it mostly occurs naturally.

Water vapor is a greenhouse gas, in fact, it is the one that causes the most global warming (up to 70%). However, water vapor is hardly at all caused by human activity, so it is not possible to regulate it. The next most potent gases, carbon dioxide, methane and ozone can be altered by human activity.

Answer 2

Water vapour (H2O) is a greenhouse gas because it traps the sun's heat radiated out from the earth and prevents it escaping into space. This is similar to all the other greenhouse gases. Greenhouse gases all have three atoms or more. This gives them the ability to absorb the heat.

Answer 3

Water vapour is not considered to be one of the human-caused greenhouse gases contributing to global warming (through the enhanced greenhouse effect). But it IS a greenhouse gas contributing to the normal warming of the earth through the natural greenhouse effect. It does this through the earth's water cycle.

Answer 4

It is a greenhouse gas but since it is largely emitted naturally, there is little we can do about it.