Water vapour : Explain it's role in modifying the Earth's climate
Answers
Answer:
Water vapor is actually a greenhouse gas, which traps heat in the atmosphere and causes temperatures to rise. But unlike other greenhouse gases that can linger in the atmosphere for years, water vapor usually stays in the air for a few days before falling back to Earth as precipitation.
Answer:
Water vapour in the atmosphere determines the earth's climate conditions. It causes rain. It controls the rate of evaporation from the bodies of plants and animals and from water bodies like lakes and oceans.
Explanation:
What are the importance of water vapour to weather and climate?
I notice that another responder has jumped in with the fine old denialist trope that “Water vapor is THE dominant greenhouse gas…” (and therefore CO2 can’t matter much).
The first part of that is entirely true. What he ignores [deliberately?] is that water vapor’s mean residence time in the atmosphere is 8–10 days. So the feedback of the water cycle (evaporation, clouds, precipitation) is rapid and complete on time scales of hours, days, and weeks. Whatever the drastic local swings in humidity, there is no global change in the atmosphere’s mean water vapor content (and thus its warming effect) in any period shorter than glacial cycles.
CO2 has a much longer residence time. (I find the evidence for ~35 years most convincing; other estimates go to 100 years or longer, and even AGW skeptics can’t fudge it below 5 years.) Absorption of CO2 by plants can’t keep up with human emissions: that’s a fast, carbon-neutral cycle unless we make huge changes in land use worldwide. Solution of CO2 in the oceans can’t keep up: they take millennia to mix and sequester carbon in deep waters and carbonate sediments.s. So CO2 (and its warming effect) does accumulate over decades and centuries as water vapor does not.
Think of it as a “tortoise vs. hare” race in which the hare doesn’t just stop to rest — it keeps running back to the starting point and beginning again. It doesn’t matter how often or loudly you shout “But the hare is so much faster!”