Start at around 28mins....ENJOY.....
So, I noticed the graph of climate change and magnetic field strength...Suzuki noted that there have been times where abrupt changes in the field strength correlated to climate change. But if you look at the two time series, it's obvious that the correlation is very weak. There are times when the two series are moving in opposite direction, there are times when they moving together, and overall the two series move in completely different directions as both series progress. Weak correlations are even less interesting than strong correlations.
I grabbed a screen shot:
Suzuki also noted that this theory has no corroborating evidence. If abrupt changes can cause climate change, then shouldn't gradual changes also cause climate change? So, why is the correlation so poor? What's the causal mechanism? They mention clouds as a possible candidate. Does it square with observations such as winters warming faster than summers?
And then it links back to Svensmark and cosmic rays. Others have looked at Svensmark work, which has been noted by many to suffer from problems, such as no explanation of cosmic rays increasing cloud condensating nuclei in the presence of abundant cloud condensating nuclei, nor has this been quantified with a radiative feedback. Other shave looked at this, and the results are mixed. The sign of the radiative forcing is uncertain, whether it is warming or cooling, and others have found the
magnitude is very, very small, too small for the cosmic rays to explain the changes in cloud properties.
It's not for a lack of looking, it just doesn't seem very convincing, especially when Svensmark's analysis rests on using a single
database with known problems (ISCCP).
Here's a few other looks:
http://www.europhysicsnews.org/inde...url=/articles/epn/pdf/2010/01/epn20101p27.pdf
They conclude that cosmic rays may be responsible for a small portion of observed warming.
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Looking at altitude and latitude, they find no response in global cloud cover to
Forbush decreases.
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And this study examined the structure of the correlations reported by Svensmark and others, and finds:
Most features of this connection viz. an altitude dependence of the absolute values of CC and CR intensity, no evidence for the correlation between the ionization of the atmosphere and cloudiness, the absence of correlations in short-term low cloud cover (LCC) and CR variations indicate that there is no direct causal connection between LCC and CR in spite of the evident long-term correlation between them.
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This study tests the causal link, and they find:
A decrease in the globally averaged low level cloud cover, deduced from the ISCCP infrared data, as the cosmic ray intensity decreased during the solar cycle 22 was observed by two groups. The groups went on to hypothesize that the decrease in ionization due to cosmic rays causes the decrease in cloud cover, thereby explaining a large part of the currently observed global warming. We have examined this hypothesis to look for evidence to corroborate it. None has been found and so our conclusions are to doubt it. From the absence of corroborative evidence, we estimate that less than 23%, at the 95% confidence level, of the 11 year cycle change in the globally averaged cloud cover observed in solar cycle 22 is due to the change in the rate of ionization from the solar modulation of cosmic rays.
That's just a taste of what is out there. Of course there are a few authors like Svensmark who continue to look at it, but it appears that they are fixated on their pet theory, despite the abundance of problems that many others have noted.
Filed under interesting.