In short, you have no refutation to offer.
I don't know that I can refute a
Torygraph article to your satisfaction, but I'll give it a shot.
"Henrik Svensmark, a weather scientist at the Danish National Space Centre who led the team behind the research, believes that the planet is experiencing a natural period of low cloud cover due to fewer cosmic rays entering the atmosphere.
This, he says, is responsible for much of the global warming we are experiencing. "
Cosmic rays are directly measured, and have been since the 50's. There's no observed decrease (or increase) in cosmic rays. In light of that, Svensmark's staetment is a little surprising.
"
Mr Svensmark last week published the first experimental evidence from five years' research on the influence that cosmic rays have on cloud production in the Proceedings of the Royal Society Journal A: Mathematical, Physical and Engineering Sciences. This week he will also publish a fuller account of his work in a book entitled The Chilling Stars: A New Theory of Climate Change."
As I recall, this was something along the lines of how to use a cloud-chamber. It's hard to see how he could have performed an experiment on any larger scale - in the real atmosphere, for instance - so its relevance remains questionable in the real world.
"
A team of more than 60 scientists from around the world are preparing to conduct a large-scale experiment using a particle accelerator in Geneva, Switzerland, to replicate the effect of cosmic rays hitting the atmosphere.
They hope this will prove whether this deep space radiation is responsible for changing cloud cover. If so, it could force climate scientists to re-evaluate their ideas about how global warming occurs."
The words and wisdom of a
Torygraph science corresponent. The scientists involved are not "hoping" to "prove" anything. They're going to conduct another lab-experiment and see what comes up.
Svensmark's argument seems (from what I've seen) to be about cosmic rays creating nucleation sites, not about whether those nucleation sites actually lead to more clouds. That's only going to happen if the atmosphere isn't already saturated with nucleation sites, taking into consideration temperature and relative humidity. Which is to say, it will only influence near-saturated air.
' Giles Harrison, a cloud specialist at Reading University said that he had carried out research on cosmic rays and their effect on clouds, but believed the impact on climate is much smaller than Mr Svensmark claims.
Mr Harrison said: "I have been looking at cloud data going back 50 years over the UK and found there was a small relationship with cosmic rays. It looks like it creates some additional variability in a natural climate system but this is small." '
A
small relationship, and no mention of a
trend in that quote. "Variablility" works both ways, and doesn't necessarily involve a trend.
Svensmark's hypothesis involves several assumptions. That there's been a reduction in cosmic rays - which there hasn't during the current warming period. That there's been a decrease in global cloud-cover - which I've yet to see any evidence for.
AAnd a third assumption is that cloud-cover has an overall cooling effect, but opinion's still divided on that. It has a cooling effect by increasing albedo, but that only operates during day-time; it has a warming effect day and night. The cosmic rays are coming in day and night as well, of course.
Night-time (and winter) warming has been more rapid than day-time and summer warming, which would be an odd result were increased insolation behind the warming.
As an alternative explanation for the current warming period Svensmark's hypothesis is shaky at best.
