pleaserecycle said:
Locknuts said:
pleaserecycle said:
The estimated 2°C rise occurs throughout 1000 years in the first paper.
The second paper briefly mentions in the introduction that a doubling of carbon dioxide would lead to an increase in the range of 1.3°C to 2.3°C, but the paper has nothing to do with those numbers. They were referencing another paper that produced those values. I'm not sure where the .51 value originates.
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Oh man sorry. I think it's meant to be .56 if the indirect effects of aerosols are taken out of the equation. That's what I got from the climate sensitivity section anyway:
"6. Empirical Climate Sensitivity [20] Using equations (14), (9), and (5), the range of the ocean uptake efficiency, from Table 2, and both the radiative forcing of increasing concentration of CO2 and reduced AOD, the empirical climate sensitivity is l ¼ 0:29 to 0:48 0:12 K=Wm2 ð15Þ where ±0.12 K/Wm2 (equation won't copy properly, sorry) represents our estimate of uncertainty due to approximations used and due to uncertainty in selected parameters (Table 1). If the aerosol indirect effect is neglected the climate sensitivity increases to 0.56 K/Wm2 "
This is where I need help, not with typos (lol) but with my limited understanding of what I'm reading. I'm keen to learn so please feel free to correct me.
This certainly is not representative of most of the stuff I've tried to read. But still a lot of stuff seems to have come out since around 2008 that points to less than 2C warming for a doubling of Co2.
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No problem. That value is the climate sensitivity, so it's the change in global surface temperature per radiative forcing. Usuaually if we want to get the change of temperature from that value, we need to multiply it by the radiative forcing to cancel out the W/m^2 units; however, this paper also includes the "effiency of ocean heat uptake" in their equation. I don't know enough about ocean heat uptake to comment on it, though.
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So the radiative forcing is the 1.5 to 4.5 figure that the IPCC claim? That makes it very hard to predict IMO. I'm surprised they haven't narrowed it down. But then again this is the Earth's climate we're talking about here...
Edit: Oops. The 1.5 - 4.5 is degrees C, and it's the climate sensivity after various feedbacks (cloud cover, water vapor etc) have been taken into account. There does seem to be a fair bit of dispute regarding the feedbacks though. I'm currently trying to figure out if they used an average of all peer reviewed papers or a specific set.
