Dr. Kirkby was immediately condemned by climate scientists for minimizing the role of human beings in global warming. Stories in the media disparaged Dr. Kirkby by citing scientists who feared oil-industry lobbyists would use his statements to discredit the greenhouse effect. And the funding approval for Dr. Kirkby's path-breaking experiment -- seemingly a sure thing when he first announced his proposal-- was put on ice.
Dr. Kirkby was stunned, and not just because the experiment he was about to run had support within his scientific institute, and was widely expected to have profound significance. Dr. Kirkby was also stunned because his institute is CERN, and science performed at CERN had never before seemed so vulnerable to whims of government funders.
CERN is no fringe laboratory pursuing crackpot theories at some remote backwater. CERN, based in Geneva, is the European Organization for Nuclear Research, a 50-yearold institution, originally founded by 12 countries and now counting 20 country-members. It services 6,500 particle physicists -- half of the world's total -- in 500 institutes and universities around the world. It is building the $2.4-billion Large Hadron Collider, the world's most powerful particle accelerator. And it is home to Jasper Kirkby's long-languished CLOUD project, among the most significant scientific experiments to be proposed in our time. Finally, almost a decade after Dr. Kirkby's proposal first saw the light of day, the funding is in place and the work has begun in earnest.
New atomsmasher research into cloud formation
By Andrew Orlowski •Posted in Science, 25th August 2011 10:42 GMT
CERN's 8,000 scientists may not be able to find the hypothetical Higgs boson, but they have made an important contribution to climate physics, prompting climate models to be revised.
The first results from the lab's CLOUD ("Cosmics Leaving OUtdoor Droplets") experiment published in Nature today confirm that cosmic rays spur the formation of clouds through ion-induced nucleation. Current thinking posits that half of the Earth's clouds are formed through nucleation. The paper is entitled Role of sulphuric acid, ammonia and galactic cosmic rays in atmospheric aerosol nucleation.
This has significant implications for climate science because water vapour and clouds play a large role in determining global temperatures. Tiny changes in overall cloud cover can result in relatively large temperature changes.
Unsurprisingly, it's a politically sensitive topic, as it provides support for a "heliocentric" rather than "anthropogenic" approach to climate change: the sun plays a large role in modulating the quantity of cosmic rays reaching the upper atmosphere of the Earth....
29 July 2011
Supporting information to press briefing on Nature publication, Kirkby et al.,
The background to the CERN CLOUD experiment.
CLOUD is tackling one of the most challenging and long‐standing problems in atmospheric science – to understand how new aerosol particles are formed in the atmosphere and the effect these particles have on climate. Increases in atmospheric aerosol particles cool the climate by reflecting more sunlight and by forming additional cloud drops, thereby making clouds brighter. increased amount of aerosol in the atmosphere caused by human activities is thought to have offset a large fraction of the warming caused by greenhouse gases. By current estimates, about half of all cloud drops are formed on aerosol particles that were “nucleated” (that is, produced from the clustering of trace atmospheric molecules rather than being emitted directly into the atmosphere, like sea spray particles). Nucleation is therefore likely to be important for climate. However, the physical mechanisms of nucleation are not understood, so global models have been based on theoretical calculations or have been adjusted to match observations. CLOUD aims to understand the nucleation process and therefore provide reliable aerosol physics to reduce the uncertainty in climate forcings and projections.
What exactly has CLOUD studied? CLOUD has studied the nucleation of new particles in a specially designed chamber under extremely well controlled conditions of temperature, humidity, ionisation and concentrations of nucleating vapours. We measured the creation of new particles caused by sulphuric acid and ammonia vapours, which have long been thought to account for nucleation in the real atmosphere. CLOUD also measured nucleation of new particles caused by ions that are generated in the air by cosmic rays. Carefully controlled laboratory experiments like CLOUD provide the best way of understanding whether cosmic rays could affect Earth’s clouds and climate, as has been proposed.
What is special about the CLOUD experiment? The CLOUD chamber has much lower concentrations of contaminants than all previous experiments, allowing us to measure the nucleation due to controlled amounts of selected trace gases without the complicating effect of undetected gases. CLOUD used state of the art instruments to measure very low concentrations of atmospheric vapours and, with a unique new instrument, has measured the chemistry and growth of newly formed charged molecular clusters from single molecules up to full particles. Another unique aspect is the capability to measure nucleation due to ionising natural cosmic rays, or due to enhanced ionisation provided by the CERN pion beam ‐ or with the effects of all ionisation completely suppressed.
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. Secondly, we have found that natural rates of atmospheric ionisation caused by cosmic rays can substantially enhance nucleation under the conditions we studied – by up to a factor of 10. Ion‐enhancement is particularly pronounced in the cool temperatures of the mid‐troposphere and above, where CLOUD has found that sulphuric acid and water vapour can nucleate without the need for additional vapours. This result leaves open the possibility that cosmic rays could also influence climate. However, it is premature to conclude that cosmic rays have a significant influence on climate until the additional nucleating vapours have been identified, their ion enhancement measured, and the ultimate effects on clouds have been confirmed.
Be seeing you.