DaveScot on Global Warming

12 September 2007

There is overwhelming agreement in the scientific community that greenhouse gas emissions have a warming effect on the planet, and that most of the observed warming of the past 50 years has been due to this cause (see IPCC 2001, NAS, The Royal Society, pretty much every National Academy of Sciences, IPCC 2007, American Meteorological Society, American Geophysical Union, American Institute of Physics, American Astronomical Society, AAAS, etc.).
None of those organizations deny that there have been warming and cooling cycles in the past (see Milankovich Cycles). They have just found that the recent emissions of greenhouse gases (beginning around the Industrial Revolution) have contributed a warming effect that is now more significant than the previous solar cycles. Indeed, it has still been warming over the past 20 years despite the fact that solar influence has been going down (see Recent oppositely directed trends in solar climate forcings and the global mean surface air temperature).

Now, the perpetually dishonest DaveScot, over at Intelligent-Design activist William Dembski's weblog, has the following headline:
"Hundreds of Scientists Have Published Evidence Countering Man-Made Global Warming Fears".

So how does DaveScot back this up? By citing the following press release from the Hudson Institute, a conservative think-tank:

A new analysis of peer-reviewed literature reveals that more than 500 scientists have published evidence refuting at least one element of current man-made global warming scares.

Okay, let's see what they found.
More than 300 of the scientists found evidence that 1) a natural moderate 1,500-year climate cycle has produced more than a dozen global warmings similar to ours since the last Ice Age and/or that 2) our Modern Warming is linked strongly to variations in the sun’s irradiance. “This data and the list of scientists make a mockery of recent claims that a scientific consensus blames humans as the primary cause of global temperature increases since 1850,” said Hudson Institute Senior Fellow Dennis Avery.

Wow, there's a lot going on here. First off, nobody disputes that there have been warming cycles in the past. So that does nothing to advance your argument, and does absolutely nothing to contradict current scientific thought. Second, scientists have been saying for years that climate forcings from CO2 have been growing in significance since 1850 (CO2 stays in the atmosphere for 50-200 years, so its effect is cumulative), but have only become the primary forcing agent in the past 50 years.

As far as irradiance goes, take a look at this graph from the above-cited Royal Society paper:

Notice how solar irradiance (on the top) is going in the opposite direction from the temperature (on the bottom).

I won't bother going through the entire article, but this bit also grabbed my attention: "corals, trees, birds, mammals, and butterflies are adapting well to the routine reality of changing climate"

Just to pick the first one out, how can they say that corals are "adapting well"? They are now being classified as "critically endangered", and scientists predict that 50% will be gone by 2030. I'd sooner call this "adapting poorly" than "adapting well."

Oh, and one more thing. It turns out that the Hudson Institute is funded in part by Exxon-Mobil.

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