Wired Blog Network – July 3, 2007
Excellent blog article and semi-civilized comments on cosmic rays and climate change. As you may know, many people think that cosmic rays are the root of the current trend in global warming. I think the jury is still out on this subject, the arguments for and against all seem a little vague to me.
This blog entry concerns a paper that has just been released called “Cosmic Rays and Global Warming” that will be presented at the 30th International Cosmic Ray Conference, held in Merida Mexico from July 3 – July 11, 2007 (sounds like a happening event – how do I get an invitation). The paper refutes many of the theories about the creation of clouds by cosmic rays and proposes that the effect does not occur.
Once again, I cannot lay claim that this paper has it right or wrong. I do think it is EXACTLY the effort that we need – complete discussion of the competing theories. Regardless of what former Vice President Gore claims, the science is not irrefutable and we need to have complete and open dialog on all of the possible scenarios. I commend the conference for having this discussion and, regardless of my above attempt at humor, I am sure that it will be a very good event for those that are involved in that subject.
There are still those who reject the evidence that humans have an impact on global temperatures, and instead maintain that natural processes are at the root.
One of these natural causes, they say, could be from cosmic rays.
When the cosmic rays interact with the Earth’s atmosphere, especially the low level clouds, they create ions of varying strength and charge. These ions would then contribute to the formation of dense clouds, blocking the Sun’s rays and reducing the effect of heating.
According to Sloan and Wolfendale, the 2000 paper highlighting the connection between cosmic rays and low-level clouds completely avoids clouds at other altitudes. This is surprising because cosmic ray ionization should increase with altitude. Cosmic rays should be intercepted earlier by the atmosphere and turned into clouds, not down at the lowest altitudes. If cosmic rays were to blame, you would expect the exact opposite, with more high-altitude clouds.
The researchers estimated the density of cloud droplets that could be produced by cosmic rays at the lowest altitudes. They found that the rate of ion production was too low generate the number of water droplets required to create clouds.
Ionized particles are channeled towards the Earth’s poles, which is why we see the beautiful auroras at the highest latitudes. If cosmic rays were causing additional cloud cover, you would expect the greatest variations around the poles. This isn’t the case; in fact, the opposite is true.
On April 26th, 1986 the reactor [in Chernobyl] released a huge cloud of radioactive particles into the atmosphere. If radiation increases cloud cover, there should have been clouds surrounding the facility for weeks. There was no evidence of unusual cloud coverage surrounding the facility after the disaster.
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Filed under: Weather science