| The IPCC models do account for both water vapor and solar irradiation. Water vapor is the dominant greenhouse gas. It is roughly correct to say that it accounts for 90% of the greenhouse effect (the lowering of infrared flux from the earth to space). However, it's not correct to say that 90% of the earth's warming is due to water vapor, if what one means by warming is change in average temperature over time. The amount of water vapor has apparently not changed very much. Here's some figures tabulated from the standard models, from the fourth IPCC working group is found here: http://ipcc-wg1.ucar.edu/wg1/docs/WG1AR4_SPM_PlenaryApproved... And a nice graph can be found here: http://en.wikipedia.org/wiki/Image:Radiative-forcings.svg These figures are estimates of anthropogenic forcing, in other words, how the components of the heat flux of the world changed due to the ecological changes. There are quite a few things here which can be measured quite accurately: cloud albedo being one, stratospheric water vapor content being another. These were estimates made in 2005. According to them, additional stratospheric water vapor accounts for less than a twentieth of a watt per square meter, and variation in solar activity less than a tenth. Anthroprogenic carbon dioxide accounts for around 1.7 watts per square meter, averaged over the year, over the earth. Solar activity is a large component, but recent estimates point at it accounting for only '18 and 36% of warming from 1950 to 1999' http://climate.envsci.rutgers.edu/pdf/StottEtAl.pdf As for the claims that measurements of global warming are taken around developing areas, I think that claim is most fraudulent. First of all, one can measure the surface heat quite accurately by satellite by looking at the ratio of radiation in different 'infrared windows'. This allows you to calculate, via the Stefan-Boltzmann radiation law, the temperature at a surface. Second of all, and perhaps more obviously, nearly all glaciers and icecaps are melting or receding, and these are not exactly developing areas! Melting ice-caps are measurements too! |
