New paper supports Svensmark hypothesis

Nigel Calder reports on a paper by Dragić et al.. The paper considers the effects of Forbush decreases - when solar flares cause reductions in the number of galactic cosmic rays reaching the Earth. According to the Svensmark hypothesis, this should cause a reduction in cloudiness.

Dragić and his co-authors have looked at the diurnal temperature range - the difference between daytime maxima and nighttime minima after Forbush increases. If clouds are indeed reduced, then the diurnal temperature range should increase, ie colder nights and warmer days.

The results look good for Svensmark's ideas.

The results [are] hard (impossible?) to explain by any mechanism except an influence of cosmic rays on cloud formation.

(H/T Pharos in Unthreaded)

WSJ on Svensmark

Anne Jolis has written an very nice, level-headed review of Svensmark and the CLOUD experiment.

But a few physicists weren't worrying about Al Gore in the 1990s. They were theorizing about another possible factor in climate change: charged subatomic particles from outer space, or "cosmic rays," whose atmospheric levels appear to rise and fall with the weakness or strength of solar winds that deflect them from the earth. These shifts might significantly impact the type and quantity of clouds covering the earth, providing a clue to one of the least-understood but most important questions about climate. Heavenly bodies might be driving long-term weather trends.

The theory has now moved from the corners of climate skepticism to the center of the physical-science universe: CERN, also known as the European Organization for Nuclear Research. At the Franco-Swiss home of the world's most powerful particle accelerator, scientists have been shooting simulated cosmic rays into a cloud chamber to isolate and measure their contribution to cloud formation. CERN's researchers reported last month that in the conditions they've observed so far, these rays appear to be enhancing the formation rates of pre-cloud seeds by up to a factor of 10. Current climate models do not consider any impact of cosmic rays on clouds.

Henrik the Bright - Josh 115

El Reg on CLOUD

Andrew Orlowski has noticed a good quote in the CERN press release about CLOUD (emphasis added):

What has CLOUD discovered and why is it important for our understanding of climate? There are several important discoveries from CLOUD. Firstly, we have shown that the most likely nucleating vapours, sulphuric acid and ammonia, cannot account for nucleation that is observed in the lower atmosphere. The nucleation observed in the chamber occurs at only one‐tenth to one‐thousandth of the rate observed in the lower atmosphere. Based on the first results from CLOUD, it is clear that the treatment of aerosol formation in climate models will need to be substantially revised, since all models assume that nucleation is caused by these vapours and water alone. It is now urgent to identify the additional nucleating vapours, and whether their sources are mainly natural or from human activities.

I am slightly confused about this though - are we saying that the models include a factor for nucleation that is equal to the rate of nucleation currently observed, and which changes based on how we think sulphuric acid and ammonia levels in the atmosphere will change in future? Or are we saying that the level of nucleation in the models is 10--1000 times too small? I assume the former, but I had also believed that the models went back to first physical principles rather than using empirical measures.

Maybe somebody can put me right here?

Update on Aug 25, 2011 by Bishop Hill

David Whitehouse has more.

Read all about it!

Given that this looks as though it is going to be a hot climatological topic for a while, if you haven't read it already then you will want to get hold of a copy of Svensmark and Calder's The Chilling Stars.

CLOUD experiment links

Updated on Aug 24, 2011 by Bishop Hill

Updated on Aug 25, 2011 by Bishop Hill

Here's some links on the CLOUD experiment results.

New Scientist, hilariously has a piece entitled

Cloud-making: Another human effect on the climate.

I kid you not folks - these guys are away with the fairies.

Click to read more ...

CLOUD results published tomorrow

Nigel Calder writes:

Long-anticipated results of the CLOUD experiment at CERN in Geneva appear in tomorrow’s issue of the journal Nature (25 August). The Director General of CERN stirred controversy last month, by saying that the CLOUD team’s report should be politically correct about climate change (see my 17 July post below). The implication was that they should on no account endorse the Danish heresy – Henrik Svensmark’s hypothesis that most of the global warming of the 20th Century can be explained by the reduction in cosmic rays due to livelier solar activity, resulting in less low cloud cover and warmer surface temperatures.

Willy-nilly the results speak for themselves, and it’s no wonder the Director General was fretful.

Read the whole thing.

Jostling for position

Michael Lemonick has an interesting article about the role of the sun in climate, inevitably discussing Svensmark's work. This has the feel of further jostling for position ahead of publication of the results of the CLOUD experiment.

[Svensmark's] idea is far from outlandish on a theoretical level, and lab experiments at the European Organization for Nuclear Research near Geneva have shown that this can actually happen. Moreover, Svensmark and several collaborators have claimed to see a correlation between the sunspot cycle and cloud cover — more clouds when the Sun is quiet, fewer when it’s acting up.

Update on Aug 3, 2011 by Bishop Hill

Lemonick has just posted a correction to the article - he had got the relationship between cosmic rays and climate back to front.

Gagging the sceptics

Nigel Calder is reporting the remarkable news that CERN is forbidding its scientists from "interpreting" the results of Svensmark's CLOUD experiment. In other words, if it's a success, one is not permitted to note that it makes a big dent in arguments for catastrophic global warming.

H/T Matthu

What we agree on

One of the interesting moments from the Cambridge conference was where Dr Eric Wolff of the British Antarctic Survey tried valiantly to find a measure of agreement between the two sides. I didn't get the details written down, but Dr Wolff has kindly recreated what he said at the time for me, for which many thanks are due.

In the table below, Dr Wolff's summary is in the left hand column and my comments are on the right. Blank implies broad agreement.

Click to read more ...

Huhne's damaging legacy

With serious allegations about Climate Change Secretary Chris Huhne's driving licence, the last thing our favourite politician needed was this:

Even if Chris Huhne does lose his job over allegedly persuading his ex-wife to take his penalty points for a speeding offence, he will have been in office long enough to leave a damaging legacy – last week’s Carbon Budget, which commits the UK to halving emissions of carbon dioxide by 2025.

Breezily insisting that this would set the country on a path towards ‘green growth’, Mr Huhne told the Commons that the cuts in emissions, which can be achieved only by a radical and hugely expensive reconstruction of the energy industry, would not only protect the climate, but ensure prosperity.

Others are less optimistic. According to Tata, the Indian multinational that owns the great steelworks at Newport and Port Talbot, Mr Huhne’s Budget is likely to drive much of British industry abroad – to countries including the United States, China, India, Japan and everywhere else in Europe, which have made no binding CO2 commitments, and where energy will thus remain much cheaper.

Read the whole thing (scroll down the page to find the top of the story). The article also looks at the Cambridge conference and Svensmark.

(H/T to lots of people for this one - and sorry I keep forgetting to hat-tip people. I've got one or two rather big things on at the moment. Getting snowed under.)

Oreskes and Dr Karl Part 2

Here is the second part of the BBC's show featuring Naomi Oreskes and Dr Karl.  This is extremely disreputable stuff - you will hear Naomi Oreskes say that the Medieval Warm Period was restricted to Europe (don't think so) and the current warming is greater in magnitude. You will also hear Oreskes engage in a particularly grubby smear of Henrik Svensmark and then, to add insult to injury, you will hear Dr Karl say that Svensmark's work was debunked a decade ago (in the week that it was experimentally confirmed!).

Even more remarkably, Dr Karl claims that the worst finding the CRU inquiries made was that scientists were not nice to each other - really!! Maybe he thinks a finding that "hide the decline" was "misleading" is just not serious at all. Amazing stuff. Do people in Australia find Dr Karl a credible source of information?

Oreskes & Karl Part 2

Matt Ridley on solar effects

Matt Ridley reviews evidence of solar effects on the climate.

Carbon dioxide certainly can affect climate, but so for sure can other things, and in explaining the ups and downs of past climate, before industrialisation, variations in the sun are looking better and better as an explanation. That does not mean the sun causes current climate change, but it certainly suggests that it is at least possible that forcings more powerful than carbon dioxide could be at work.