Tag: air and winds

The major greenhouse gases are water vapour, which causes about 3670% of the greenhouse effect; carbon dioxide (CO$ _2$), which causes 926%; methane (CH$ _4$), which causes 49%; and ozone (O$ _3$), which causes 37%. Water vapour is the most abundant greenhouse gas, it acts as a feedback to the climate. Water vapour increases as the earth's atmosphere warms, making these the most important feedback mechanisms to the greenhouse effect. Carbon dioxide is released through natural processes such as respiration and volcano eruptions and through human activities such as deforestation, land use changes, and burning fossil fuels. This is the most important long-lived cause of climate change.

The atmosphere is a gaseous envelope surrounding the earth. It is mostly composed of nitrogen, oxygen, argon, carbon dioxide and some other gasses in trace amounts. The atmosphere is held in place by gravity of the earth.    Thus the correct answer is option D.

Anemometer is the instrument used to measure wind velocity. Hydrometer measures specific gravity (or relative density) of liquids. Barometer is used to measure atmospheric pressure. Lactometer measures cream content of milk.