Cool it! Er, don't!

Last July, two scientists published a study claiming that cosmic rays were responsible for 66% of the atmosphere's temperature variation over the last century. The remaining handful of global warming skeptics latched on to this as yet another excuse to claim that a human factor in climate change was "unproven" and thus no preventative action need be or even should be taken.

And just like all the other excuses, this one has gone down in flames.

The principal cause of recent climate change is not cosmic rays but human activities, a group of scientists says [reports the BBC on January 23].

They say an article last year linking cosmic rays and changes in temperature was "scientifically ill-founded". ...

In Eos, the journal of the American Geophysical Union, the 11 Earth and space scientists insist that greenhouse gases remain the chief climate suspect.

There simply is no getting around the fact that human activities are having a real effect on the climate - and not an overall good one. Even after you allow for all the other explanations (natural variations, changes in the Sun, and so on) you're still left with a major portion of the general warming trend detected over the last 100 - particularly the last 50 - years which can only be attributed to us. And the only answer, the only way to avoid or at least mitigate the coming disaster, is to do less of what we, particularly those of us in the US, do: waste energy and produce greenhouse gases.

For their part, Jan Veizer, one of the two scientists who produced the cosmic ray claim, says "It's a long story, and the whole issue is politically driven." Which is what the naysayers always claim where their data is shot down.