…and Then There’s Physics commented
There is a fundamental difference, though. WV is limited by the Classius Clapeyron relation. This really just depends on the temperature in the atmosphere. Of course, you’re right, that technically we could simply add WV until the atmosphere is saturated everywhere. This doesn’t appear to happen and I think the reason is that convection carries the WV vertically until it reachs an alititude where RH is close to 100%, then it condenses, forms clouds and precipitates. So, if the RH is approximately constant, then the amount of WV in the atmosphere will remain approximately constant. There is no fundamental reason why excess WV should be replaced after being precipitated.
CO2 is slightly different. We’re taking CO2 that has been buried for millions of years and releasing it into the atmosphere. This increases the amount of CO2 in the ocean/atmosphere/biosphere. The amount in the atmosphere is then set by the carbon cycle (Henry’s Law for the oceans). The only way to reduce this is for the CO2 to form calcium carbonate and precipiate to the ocean floor (I think), or to be buried as biological matter. This is a very slow process. Therefore, even though an individual CO2 molecule may only remain in the atmosphere for years, the time it will take for an increase atmospheric concentration to decrease is much much longer (centuries).
While I’ve not really looked at it this before, it seems WV is limited by the Classius Clapeyron relation with atm temp and Co2 is limited by Henry’s Law related to Ocean temps, right?
Rel humidity averaged ~70% in my data set, that sounds about like the right amount of WV left in the atm after night time cooling condenses out WV in excess of that amount.
And we know we emit more Co2 than what shows up in the atm concentration, and the images from that new satellite seems to show, well doesn’t seem to show any real human sources (that I noticed), that the big process looked distinctly not human.
Lastly, I don’t think the surface data show any sign of a loss of night time cooling.
Look, I may not know down to my bones like you do that Co2 has to cause warming, I know in my head it should, I know enough about EM fields to accept it, but I have enough lab experience, I like looking at stuff myself, and I’m well qualified in simulators and large amounts of data, this I can do competently, and in NCDC’s data there’s no sign of it. There is lots of other really large disturbances in the data, so sure you can write a model of how you think surface temps will (have?) evolved from Co2, and get a line that goes up, but tomorrow morning will be on average about the same temp as tomorrow to normal measurements, the average derivative of max temps is +/-0.0F, temp have gone up (and down), but night time cooling went up(down) with it.
This just shows why, which reminds me of your original comment
it’s not so much being underwhelmed by the paper itself (I agree with JCH, Graeme Stephens seems to be a very good researcher and this seems to be an impressive piece of work) as being underwhelmed by what some appear to be concluding. As I see it, the work has measured the albedo very accurately and has shown that there is a North-South symmetry. I don’t think that one can really make any strong conclusions with regards to cloud feedbacks as they are expected to be small anyway. There does appear to be an issue with climate models not capturing this symmetry and that this may have implications for the hydrological cycle (if they’re not getting the right distribution of clouds, they’re unlikely to properly represent changes in precipitation). So, this is certainly interesting, but I don’t really see how it implies anything all that significant with respect to how our climate will respond to changes in anthropogenic forcings.
I think there’s a lot in this paper that fits the data I have, and I see no reason CS is over ~1.1C, and from the surface data it seem it has to be lower still.
A couple of Nasa GCM review papers, at least one discusses large differences in the hydrological cycle (rain patterns).
http://icp.giss.nasa.gov/research/ppa/2001/mconk/
http://icp.giss.nasa.gov/research/ppa/2002/mcgraw/