【多选题】About the role of water vapor, which states are right?
A.
The average residence time of a water molecule in the atmosphere is much shorter than CH4 and CO2.
B.
The vapor concentration in the atmosphere increases as the temperature increasing. Because water vapor is a greenhouse gas, this results in further warming and so is a "positive feedback" that amplifies the original warming.
C.
Water vapor has mainly contributed to the global warming.
D.
Water vapor concentrations fluctuate regionally, but human activity does not significantly affect water vapor concentrations except at local scales, such as near irrigated fields.