Films/DVD Asylum

Posted by Duilawyer (A) on March 03, 2007 at 17:20:31

In Reply to: And now, that silly erstwhile editor of New Scientist, in the Times of London posted by clarkjohnsen on March 3, 2007 at 12:58:05:

There are many things that could be said about the article, but it makes one important point. Calder says that the sun has become increasingly active over the 20th century, but the activity has levelled off, and that this corresponds with a levelling off of global warming noted since 1999.

He also points to a paper by Henrik Svensmark, published in the proceedings of the Royal Society, demonstrating the role of cosmic rays in the formation of rain clouds. Calder’s summary of the issue is:

[Svensmark] saw from compilations of weather satellite data that cloudiness varies according to how many atomic particles are coming in from exploded stars. More cosmic rays, more clouds. The sun’s magnetic field bats away many of the cosmic rays, and its intensification during the 20th century meant fewer cosmic rays, fewer clouds, and a warmer world.
The problem with Calder’s thesis does not lie in Svensmark’s work, but in the fact that he has selected perfectly good science to bolster a claim that is not supported by the evidence.

The Climax station in Colorado has been measuring cosmic rays reaching the earth since 1953 (before the rapid warming of the last three decades or so). I have created a graph from the Climax Station data, and included it here. Click on the thumbnail to see the full sized version.

Notice that whilst there is a (well known) ten year cycle to these data, there is emphatically not any trend here. It is not the case that the sun’s magnetic field has been intensifying (until 1999) and thus batting away more cosmic rays. These data show that, whilst Svensmark’s thesis is excellent science, and furthers our understanding of cloud formation, it says absolutely nothing about the climate change we have been experiencing over recent decades.

Nigel Calder does us a disservice, by confusing the data in this way. (Indeed, the levelling off since 1999 he mentions is also wrong I think. I will see if I can get hold of some data).

Realscience.org I think, I will psot the link if anyone wants it. OR USE THE GOOGLE!!!