Global Warming Potential of water vapor?

Question

What is the Global Warming Potential of water vapor? Carbon dioxide has a GWP of 1. What about water?

Answer 1

Actually, it's pretty well accepted that water vapor is responsible for 98% of the normal greenhouse effect. Both water and carbon monoxide have vibrational absorptions in the mid-IR and water certainly has a strong rotational absorption in the far-IR. Don't worry, we need the greenhouse effect to keep us from freezing so this is neither new nor bad. It is worth pointing out that even if we double CO2 concentrations in the atmosphere, we certainly haven't doubled the greenhouse effect, we've only doubled that small 1.5% contribution from CO2. Climatologist Richard S. Lindzen offers a good primer on the scientific phenomenon we call the green house effect if you follow the source link and scroll down to "The Greenhouse Effect"

Answer 2

That is a good q. As the earth warms-more H20 in atmosphere = more water vapor, more potential for clouds/cloud cover. I've never seen a cloudy day hotter than a sunny day. Could that act as a negative feedback? Also, more water vapor, more precipitation.

Interesting that no ones seems to calculate the GWP of water vapor. It seems to be mostly ignored when evaluating the effects of carbon dioxide on GW. Information that I have looked at leads me to believe that the GWP of water vapor would be lower than CO2 but the overall effect of water vapor is so much higher because there is so much more of it in the atmosphere.

Answer 3

This is a good Q. As the earth warms-more H2O in atmosphere-more global warming-more ice melting-more acid rain CO2+H2O. Another good Q is: What was the planet like when Earth was all one temp and plants grew on the poles?

Answer 4

maximum flights are interior of sight and commute must be finished with severe speed trains, going 200 mph. there is not any environmental experience in any worldwide places infrastructure, maximum in lots of instances no longer even employer experience. i might first forbid any vehicle using extra then a million Gallon in line with 50 miles. I drove a snug vehicle interior the 80's with 56mpg, what happened to technologies?. next, i might provide up city sprawl and get human beings returned to stay, the place they artwork.