[cogitator]

I would ask the question how much of that 0.36 F figure takes into account the "heat island" effect from the massive metropolitan areas represented by the likes of major cities such as LA, Houston, Chicago, NY, Tokyo, the Dallas-Ft.Worth area, etc.?

Certainly a regional effect; not much of a global effect.

The Surface Temperature Record and the Urban Heat Island

Pithy excerpt:

"... there is little difference between the long-term (1880 to 1998) rural (0.70°C/century) and full set of station temperature trends (actually less at 0.65°C/century)."

If the effect of cities was substantial, the full set including city stations would be expected to be pulled upward by urban heat islands and be higher than the trend in the rural station set.

[DustyMoment]

Certainly a regional effect; not much of a global effect.

I concur, I didn't mean to imply that the heat island effect of the large metropolitan areas were, in and of themselves, affecting global temps. However, at a macroscopic level, there should be some cumulative affect, especially when the heat island effect is measured against the regional temps of the LA basin, for example. I do have a hard time reconciling the fact that with all of the discussion about GW, the heat island effect has negligible impact. That doesn't mean that i believe it has a huge affect, but it has to have some.