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I had just assumed it was logarithmic due to my high school understanding of the greenhouse effect. To save people googling, it appears that I was right [0], h

I had just assumed it was logarithmic due to my high school understanding of the greenhouse effect. To save people googling, it appears that I was right [0], however this is not try for all greenhouse gasses. For instance, methan grows as sqrt(x), and CFCs are linear. Admittedly, the linked expressions are empirical, so only represent an approximation for the range of values that we have observed. There are also dynamic effects (such as increased water vapor, or a runaway release of trapped methane) that are not being moddeled by estimates of thermal forcing. [0] http://www.esrl.noaa.gov/gmd/aggi/aggi.html http://www.esrl.noaa.gov/gmd/aggi/aggi.html

kapitza 10y ago
The thermal forcing is just the input to the model. What we'd really like to know is the climate sensitivity -- how does a given forcing affect Earth's temperature? All questions about the legitimacy of climate science are questions about whether simulations of the earth's atmosphere ("general circulation models") can be validated or have predictive power, at least with realistic computing resources. However, the big-O question is an interesting reflection on the ratio between how much scientific communication effort goes into influencing the public, versus educating the public. There is also not much funding available for studying positive impacts of global warming. Scientists have known about the Arrhenius effect for over a century, and in pre-WWII texts the treatment is generally "isn't it cool that burning fossil fuels not only gives us power and light, but is good for agriculture and might prevent the next ice age?" The past is a foreign country, and in that country it was generally assumed that warm periods were good for humans and cold ones were bad. (Mostly because ag yields.) They didn't even really think about it -- and nor do we think much about it, either. Plus ca change...

kapitza 10y ago

The thermal forcing is just the input to the model. What we'd really like to know is the climate sensitivity -- how does a given forcing affect Earth's temperature? All questions about the legitimacy of climate science are questions about whether simulations of the earth's atmosphere ("general circulation models") can be validated or have predictive power, at least with realistic computing resources. However, the big-O question is an interesting reflection on the ratio between how much scientific communication effort goes into influencing the public, versus educating the public. There is also not much funding available for studying positive impacts of global warming. Scientists have known about the Arrhenius effect for over a century, and in pre-WWII texts the treatment is generally "isn't it cool that burning fossil fuels not only gives us power and light, but is good for agriculture and might prevent the next ice age?" The past is a foreign country, and in that country it was generally assumed that warm periods were good for humans and cold ones were bad. (Mostly because ag yields.) They didn't even really think about it -- and nor do we think much about it, either. Plus ca change...