If both lower CO2 sensitivity and net positive up to 3 degrees of warming were correct then global warming is not net bad until 2080 to 2180
by noreply@blogger.com (brian wang) from NextBigFuture.com on (#2GD9Z)
There is a lot of research that the world's climate is less sensitive to CO2 than the main current models of climate change.
Without any feedbacks, a doubling of CO2 (which amounts to a forcing of 3.7 W/m2) would result in 1 C global warming, which is easy to calculate and is undisputed. The remaining uncertainty is due entirely to feedbacks in the system, namely, the water vapor feedback, the ice-albedo feedback, the cloud feedback, and the lapse rate feedback.
A committee on anthropogenic global warming convened in 1979 by the National Academy of Sciences and chaired by Jule Charney estimated climate sensitivity to be 3 C, plus or minus 1.5 C. Only two sets of models were available; one, due to Syukuro Manabe, exhibited a climate sensitivity of 2 C, the other, due to James E. Hansen, exhibited a climate sensitivity of 4 C. "According to Manabe, Charney chose 0.5 C as a not-unreasonable margin of error, subtracted it from Manabe's number, and added it to Hansen's.
Various empirical models and inverse models suggest doubling CO2 gives a 1.3 to 1.4 degree warming.
This means at least maybe three doublings compared to 4 degree sensitivity warming. This means eight times as much CO2 could be emitted.
There is also research that the net benefits (good effects less bad effects) are positive up to 2 to 3 degrees of warming.
Here is a links to positive versus negative effects with links to research papers.
If both the lower sensitivity and the net positive effects up to 3 degrees of warming were correct then it would be a net positive up until about 2080 to 2180.
Read more
Without any feedbacks, a doubling of CO2 (which amounts to a forcing of 3.7 W/m2) would result in 1 C global warming, which is easy to calculate and is undisputed. The remaining uncertainty is due entirely to feedbacks in the system, namely, the water vapor feedback, the ice-albedo feedback, the cloud feedback, and the lapse rate feedback.
A committee on anthropogenic global warming convened in 1979 by the National Academy of Sciences and chaired by Jule Charney estimated climate sensitivity to be 3 C, plus or minus 1.5 C. Only two sets of models were available; one, due to Syukuro Manabe, exhibited a climate sensitivity of 2 C, the other, due to James E. Hansen, exhibited a climate sensitivity of 4 C. "According to Manabe, Charney chose 0.5 C as a not-unreasonable margin of error, subtracted it from Manabe's number, and added it to Hansen's.
Various empirical models and inverse models suggest doubling CO2 gives a 1.3 to 1.4 degree warming.
This means at least maybe three doublings compared to 4 degree sensitivity warming. This means eight times as much CO2 could be emitted.
There is also research that the net benefits (good effects less bad effects) are positive up to 2 to 3 degrees of warming.
Here is a links to positive versus negative effects with links to research papers.
If both the lower sensitivity and the net positive effects up to 3 degrees of warming were correct then it would be a net positive up until about 2080 to 2180.
Read more