Cosmic rays, solar activity, and temperature change

One of my New Year’s resolutions was to stop posting comments to Australian politician Craig Kelly’s Facebook page. He’s a climate change denier and posts a lot of very selective stuff on climate, coal, socialism, crime, etc and his followers get sucked right in. The other day, I tried to post the following in response to an article he posted by some Russian scientists who had written a paper, ‘Cosmic rays, solar activity, and changes in the earth’s climate’, trying to link cosmic rays and solar activity to global temperatures. By the time I finished writing it, there was a message to say I might not be authorised to post comments here and I noticed my other posts had gone. I guess he’s done me a favour. Here’s what I hadn’t intended to post …

“Cosmic ray fluxes have been monitored since about 1950 and no significant trend is apparent. Similarly, there have been no significant trends in solar activity since at least the 1970s (it has probably gone down a fraction) except of course the 11-12 year cycles.

The authors seem to be forecasting that cosmic ray fluxes will increase, leading to greater cloud formation which will mean cooler temperatures. Their work seems to use the same principle as that of Henrik Svensmark of Denmark who has been going on about the effect of cosmic rays on cloud formation and global temperatures for a couple of decades. He says cosmic rays have decreased over the last 100 years, leading to less cloud formation and therefore higher temperatures, rather than the higher levels of CO2 causing the higher temperatures. Many studies have been done to try and replicate his work but they find little or no correlation between cosmic rays and cloud cover.

For his theory to be correct, there has to be a long term increase in the solar magnetic field. But this and other measures of solar activity haven’t increased. There is good satellite data back to the 1970s. When you look at the sun’s energy output as measured by watts per square metre, it has fluctuated between about 1366 and 1367 in short term cycles of about 11 years, and a slight decline if anything in the long term. It’s different if you’re looking at a scale of many thousands or millions of years.

Also, there needs to be a long term negative trend in cosmic ray flux and there isn’t; there’s no significant trend. Also, there needs to be a link between cosmic rays and cloud formation but various studies have found no significant link. And there also has to be a long term negative trend in low level cloud cover, and that hasn’t been the case either.

Good luck to the Russian scientists with their cooling forecast. They might need it.”