Gavin Schmidt wrote this, as part of a response to Michael Crichton's "State of Fear", far better than I could have done and it's quicker to post what he said than write it myself:
"The first set of comments relate to the attribution of the recent warming trend to increasing CO2. One character suggests that “if CO2 didn’t cause the global cooling between 1940 and 1970, how can you be sure it is responsible for the recent warming?” (paraphrased from p86) . Northern Hemisphere mean temperatures do appear to have cooled over that period, and that contrasts with a continuing increase in CO2, which if all else had been equal, should have led to warming. But were all things equal? Actually no. In the real world, there is both internal variability and other factors that affect climate (i.e. other than CO2). Some of those other forcings (sulphate and nitrate aerosols, land use changes, solar irradiance, volcanic aerosols, for instance) can cause cooling. Matching up the real world with what we might expect to have happened depends on including ALL of the forcings (as best as we can). Even then any discrepancy might be due to internal variability (related principally to the ocean on multi-decadal time scales). Our current ‘best guess’ is that the global mean changes in temperature (including the 1940-1970 cooling) are actually quite closely related to the forcings. Regional patterns of change appear to be linked more closely to internal variability (particularly the 1930’s warming in the North Atlantic). However, in no case has anyone managed to show that the recent warming can be matched without the increases in CO2 (and other GHGs like CH4)."
With respect to the bolded emphasis on solar irradiance, refer to the solar cycle length vs. temperature plot that I posted earlier.
As for your other links, I already responded briefly, because I certainly don't have unlimited time to address all the errors that I saw when I examined them. (And I'm only an amateur.) If you were willing to let me deal with one link a week after the holidays, I might be able to.