Update on the CLOUD experiment at CERN

Rik Gheysens says: in Tips and Notes

The latest results of the CLOUD experiment in CERN are published: http://science.orf.at/stories/1717291/. It’s a German article with the following statements of Jasper Kirkby (head of the CLOUD experiment):

At the present time we can not say whether cosmic rays affect the climate. What we have investigated so far, is the production of condensation nuclei for cloud droplets, namely those arising from gases: The technical term is “gas-to-particle conversion”. They make up about half of condensation nuclei in the atmosphere. The remaining germs come from soot and dust.

Which gases are involved in this process?

We first looked at sulfuric acid and ammonia. The results of the first tests were: the cosmic rays enhance the formation of condensation nuclei from gases by a factor of ten. But that alone is not enough to significantly affect the formation of clouds. According to our previous experiments, there must be other gases or vapors that enhance this process. Presumably organic substances.

Which substances?

The results are currently under review in a journal. Unfortunately, I can not say more about it. Only this: The results are very interesting. During the year some results will be published.

Suppose you demonstrate that cosmic rays affect the formation of clouds actually at a greater extent. What would that mean?

I believe that these experiments are significant in two respects. Firstly, because they would show a new natural source of climate change. And secondly, because it would change the understanding of anthropogenic climate change. We are well informed about greenhouse gases. But we know too little about aerosols. Also airborne particles that pass through our industry in the atmosphere.

You have a cooling effect with certainty. But we have no idea how big this effect is. It might be small, but also very large. Maybe it is so large that it compensates for the effect of additional CO2 in the atmosphere. We do not know.