The cosmic climate mystery is solved!

Scientists have known for a long time that solar activity correlates well with climatic conditions on Earth. This should surprise no one since our home star is an enormous source of energy, only a tiny fraction of which is intercepted by the Earth. Yet that is enough to raise the temperature of our planet from near absolute zero to the relatively comfortable 15^o C we enjoy today. The fact that, in 2004, Prof. Dr. Sami K. Solanki, now of the Max Planck Institute for Solar System Research, et al, foundthat the Sun had been more active during the previous 70 years than it had been in more than 8,000 years, should obviously have some bearing on the warming of the late 1990s.Dr. Henrik Svensmark,physicist and professor in the Division of Solar System Physics at the Danish National Space Institute in Copenhagen stated:

The impact of solar activity on climate is much larger than the official consensus suggests. This is therefore an important scientific question that needs to be addressed by the scientific community.

The problem was, the direct impact of changes in solar insolation, the solar radiation that reaches the Earth's surface, was too small to account for warming observed since the start of the Industrial Revolution. For example, the Total Solar Irradiance, the amount of solar energy reaching the top of Earth's atmosphere, only varies by about 0.1% over the course of the familiar 11-year sunspot cycle. While the variations can be greater for longer cycles, for example the 200-year solar cycle, they are still insufficient to account for the observed warming, at least via direct solar insolation changes. This is why the United Nations dismisses the Sun as a candidate for the major cause of warming over the past few centuries. After all, we have no control of the Sun, of course, so the IPCC pays no attention to sunspots, an important gauge of solar activity. Instead they point to humanity's carbon dioxide (CO₂) emissions as the primary driver.

However, as I discussed in "Climate 'detective story' upends politically correct science," my previous article in this series, geologists have found that CO₂ and temperature do not show any consistent correlation over geologic time. As seen in the graph I included last week, below, at times, CO₂ levels were remarkably high, and temperatures were moderate or even low. At other times, CO₂ was low, and temperatures were high. And sometimes they were both high or low at the same time.

As explained in the caption to this important image, the changes in (see part one of this series), a proxy for temperature variations, were determined by Dr.Jan Veizer, the Distinguished University Professor (emeritus) of Earth Sciences at the University of Ottawa and Institute for Geology, Mineralogy and Geophysics of Bochum Ruhr University in Germany. Veizer was surprisedto note that the Earth warmed and cooled periodically, switching back and forth between ice house and hot house, following an approximately sinusoidal pattern with a periodicity of about 140 million years throughout the Phanerozoic, the geologic eon that covers the time period from about 600 million years ago to the present.

In the documentary, The Cloud Mystery, Dr. Veizer, said:

I suspected that the reason for this rough periodicity was something to do with the sky. But I was searching for it and couldn't find anything. So, essentially, I gave up. I didn't have an explanation.

But then one evening, Professor Veizer received an e-mail from Professor Nir Shaviv of the Hebrew University of Jerusalem in which Shaviv said that he might have an explanation for the periodic temperature changes Veizer had observed over the Phanerozoic. Shaviv explained that he had been working with galactic cosmic ray (GCR) flux, or variation, over the same time interval and that that variability has a periodicity similar to that which Veizer had found in temperature. GCRs are high energy particles that originate in supernovas in deep space, eventually flooding into our solar system. Shaviv was able to determine GCR flux by analyzing iron meteorites that originally broke off of asteroids millions of years ago and so became exposed to GCRs and then recorded evidence of GCR flux over vast time periods.

Laying Veizer's Phanerozoic temperature curve over Shaviv's GCR curve revealed the following, as published in the 2003 paper, Celestial Driver of Phanerozoic Climateby Shaviv and Veizer: