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Climate Change Effect Increasingly Visible and Measurable, Broad Studies Review Concludes

March 08, 2010

New research by Britain’s Met Office reviewed more than 100 recent studies on Climate Change.  The review concludes that is is an “increasingly remote possibility” that human activity is not the main cause of observed climate change.

This is not exactly new news. But it does offer additional recent independent studies consistent with the overwhelming already existent scientific consensus (not to be confused with the very different, and non existent “public consensus” on the issue).

Many skeptics, often without support, assert that any changes we have observed are simply due to “natural cycles” or variation. Even more egregiously, it is often asserted that the bulk, if not all, of observed changes, are due to specific factors, such as volcanic eruption; or, worse, increased solar radiation.

As Peter Stock of the Met Office, who led the review, puts it:

There hasn’t been an increase in solar output for the last 50 years and solar output would not have caused cooling of the higher atmosphere and the warming of the lower atmosphere that we have seen.

Judith Lean led a seminal study in 1998 “Reconstruction of solar irradiance since 1610: Implications for climate change,” that concluded that less than a third of the observed warming since 1970 could be attributed to solar forcing.

Since that time, solar forcing has only decreased. As NASA points out, the earth has actually been in a solar minimum recently (which, all else being equal, would tend to have a slight cooling effect).   And the longer term trend since 1978 has been for a slight cooling effect from solar activity.

Moreover, a new study last month, published in GeoPhysical Research Letters, suggests that even if predictions for an extended period of solar minimum turn out to be correct, it would have only a minimal impact upon climate in comparison to the current anthropogenic atmospheric forcing,so there’s no potential temporary respite from “sun assistance.”

And, as NASA also points out, 2000-2009 was still the warmest decade ever recorded, with 2009 being tied for the second warmest year ever recorded.

However, it should be pointed out that whether it one year or another was the warmest, of seventh warmest, is fairly insignificant.  (This has not stopped disinformants like the Washington Post’s George Will from claiming otherwise.)  What is important to note however, is the longer term trend. As NASA/GISS climatologist Gavin Schmidt notes: “The difference between the second and sixth warmest years is trivial because the known uncertainty in the temperature measurement is larger than some of the differences between the warmest years.”

It is worth noting however, that as solar activity alone would have if anything causes a slight decrease in temperatures over the last three of so decades, temperatures increased, with each suceeeding decade (1980-1989, 1990-1999, 2000-2000,) warmer than the one before it.  Yet so called climate change “skeptics” (exhibiting a position which if anything appears skeptical that the basic long term rules of physics apply to atmospheric increases in heat trapping gases when we are the cause) repeatedly assert that observed climate change is due to changes in solar radiation.

The only thing supported by the recent evidence, would be the precise opposite.