Could a longterm decline in neutron rates explain much of global warming?

Question

A neutron monitor at the south pole recorded an 8% decline in neutron rates from 1965 to 1997. This longterm trend can only be explained by longterm changes in the Suns magnetic field and is also supported by spacecraft and atmospheric balloons.

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 112, A12102, doi:10.1029/2006JA011894, 200

Long-term decline of South Pole neutron rates

J. W. Bieber,1 J. Clem,1 D. Desilets,2 P. Evenson,1 D. Lal,3 C. Lopate,4 and R. Pyle1

Received 2 June 2006; revised 8 June 2007; accepted 24 August 2007; published 27 December 2007.

"In summary, we have not been able to identify any

instrumental or environmental effect that could cause the

long-term decrease in the South Pole neutron rate. Unless

some such cause emerges in the future, it would appear the

origin of the decrease must be a change in the Sun or solar

wind, with an attendant change in the strength of solar

modulation of cosmic rays"

http://neutronm.bartol.udel.edu/reprints/2007bieber.pdf

Answer 1

One would hope that in view of public interest the authors of this work would have mentioned any of their expectations around global warming. However, unless the case were compelling, they may have published without such speculation to avoid rejection by reviewing peers on basis of inadequate proof... effectively nullifying the observations that are more evident.

It is not a scientist's role to add a lot of lightly demonstrated speculation to a paper describing observations. It is appropriate to identify things that are not in evidence. But we can not jump from absence of a comment about global warming that the author felt there was a connection.

Answer 2

There's so much we don't understand about who the climate works, and all the factors that contribute to changes in the climate.

To dismiss scientific findings out of hand because they don't match your prejudged premise causes harm to science and the pursuit of knowledge.

Answer 3

Maybe. But there doesn't seem to be a strong physical basis for thinking so. And even if there were, you still have to be able to explain why the underlying physics behind AGW theory are wrong. You can't just ignore the massive amounts of greenhouse gases we've put into the atmosphere, after all.

I think any explaination of the current warming *has* to include humanity's influence on the climate, as well as natural factors.

Answer 4

No,decreasing neutron rates suggest decreasing solar activity which would produced cooling. I have to question the usefulness of neutron rates as a factor in the global warming debate.

Answer 5

After reading the paper I would say it's possible but highly improbable.  It's possible if for some reason low-energy GCRs are exceptionally good at seeding clouds, which doesn't strike me as very plausible.

Then there are the other problems with the GCR theory.

"In addition, there is no evidence of any long-term trend in the low cloud cover, and the GCR-hypothesis has a problem with explaining the trend in the diurnal cycle, enhanced warming in the Arctic and a cooling in the stratosphere."

On top of that, "the physical link between any ultra-small particles and much larger the cloud condensation nuclei is still lacking, even after the experiment performed in Copenhagen. Thus, the hypothesis is still speculative."

And then you have to explain how this forcing could be significantly stronger than the anthropogenic greenhouse gas forcing.

It's simply not a plausible theory, but the South Pole neutron monitoring prevents it from being altogether disproven.  I'll grant you that much.

Answer 6

No.  There's no mechanism for neutron flux to cause warming.

EDIT - Also from your citation: "Cosmic rays have been hypothesized to affect formation of clouds through possible effects on production of cloud condensation nuclei. Observational evidence for such a relationship is, at best, inconclusive."

People trying to draw this link have been caught messing with the data:

"Pattern of Strange Errors Plagues Solar Activity and Terrestrial Climate Data", Damon and Laut, Eos,Vol. 85, No. 39, 28 September 2004

Not to mention not enough data to show even an incidental correlation.

CO2 has a simple, clear physical mechanism that causes warming.  The numbers work.  There are many reasons and a huge amount of data that causes the vast majority of scientists to agree that man made greenhouse gases are the majority of the problem.