What two gases act as a blanket in the atmosphere and prevent the escape of heat to outer space?
1 Answer
Carbon dioxide and water vapor.
Explanation:
The two most important gases for the greenhouse effect, which is what you are referring to, are water vapor and carbon dioxide.
Gases, such as methane, have a very strong "blanketing" effect but the actual amount of it in the air is very very small (less than 0.0002 %). There is more 200 times as much carbon dioxide in the atmosphere then there is methane. Water vapor content in the atmosphere can be as high as 5%...but it averages about 0.25% of the atmosphere. Of the greenhouse gases, water vapor is by far the largest amount.
The reason people often ignore water vapor as a greenhouse gas is that the amount is not constant around the Earth, and liquid water works in the opposite way. Liquid water (clouds) prevent sunlight from getting to the Earth in the first place.
