A thermometer for the planet

Steve Milloy, of the Junk Science Home Page, has assembled a global temperature survey.

Why is this needed?

One of the questions most frequently received here at JunkScience.com is “What is the current global mean temperature?” Certainly a reasonable question given the attention currently paid to Anthropogenic Global Warming (AGW) and one for which you could reasonably expect a good answer. Unfortunately, expectation and reality are far removed.

The average temperature of the globe is very hard to measure. It's even harder to measure meaningfully.

Even side-stepping the fact that the average temperature of the globe measures in the thousands of degrees (integrating over the entire volume, including the molten mantle and the core), how do you pick a representative sample of the fluids in the biosphere? That's what we really want – the average temperature of the air mass in the biosphere, and the average temperature of the water.

Milloy is looking at the air temperature.

There is an extensive discussion of the methodology used, and the problems that are simply not reducible. For example, there are few, if any, sea-based temperature reports available, so the vast bulk of the data set is land-based. As a result, the reported average temperature peaks at about noon over the largest land mass on the planet. The northern hemisphere is over-represented, so I expect there'll be a seasonal trend in the data as well. The arctic regions are also under-represented. These would be of great interest, since the computer models predict a greater temperature increase at the poles as the world warms.

The number being reported is a straight average of the sampling stations used. So far, no attempt is being made to weight stations in any way – that I know of.

Nevertheless, it's nifty. Check it out.