The Sun drives climate, not CO2

In a recent blog I referred to Fritz Vahrenholt’s book “The Neglected Sun”.  I’ve been aware of this book for some time, and I’ve met the author a couple of times in Brussels.  It was first published in the original German as “Die Kalte Sonne” (The Cold Sun), but its English title emphasises its key premise: that the IPCC, in attributing climate change primarily to CO₂, has ignored the Sun, which Vahrenholt argues has both a larger and a better-proven impact on climate.

Vahrenholt is remarkable, not so much for the book, as for his previous career, and his intellectual journey.  He started out as a socialist politician and passionate environmentalist.  Having studied Chemistry in Münster, he started his professional career at the federal environmental protection agency in Berlin, and the Ministry for Environment of Hesse. From 1984 till 1990 he had a leading role in environmental affairs in Hamburg, and became Senator for the Environment in Hamburg from 1991 to 1997.  A man of impeccable green credentials.

In 1998 he entered the energy industry, and until 2001 was on the Board of Deutsche Shell AG, a Shell subsidiary. In 2001 he moved to post of CEO of the wind turbine company REpower Systems AG and remained there until 2007. From February 2008 he was CEO of electric power company RWE’s renewables subsidiary RWE Innogy, a post he stepped down from in mid-2012.  Professor Doctor Vahrenholt has a doctorate in Chemistry. In 1999 he was made an Honorary Professor of Chemistry at the University of Hamburg.

So far, so successful – but perhaps not astonishing.  The remarkable thing is that during his time with Innogy, running a wind farm business, he became concerned and disillusioned to find that the business performed well below expectations, and started looking for the reasons.  He also started to look more closely at the whole theory of climate change, and became convinced that the IPCC position – that CO₂ is the primary driver of climate – was simply mistaken.

His book assembles an overwhelming case that climate correlates rather poorly with atmospheric CO₂, whereas it correlates extremely well with solar activity and astronomical cycles.  The IPCC quotes the fact that solar irradiance is fairly constant, and concludes that the sun therefore cannot be a major factor.  But it largely ignores the fact that the solar magnetic field varies significantly and cyclically, and it largely ignores the work of scientists like Svensmark, who have demonstrated the link between solar magnetism and terrestrial climate.

The solar magnetic field tends to shield the earth from the cosmic ray flux arriving from space.  A weaker magnetic field allows more cosmic rays to reach the earth, which leads to more cloud formation, higher albedo and therefore lower temperatures.  It is well established that the extreme cold periods of the little Ice Age, like to Maunder,  Dalton and Sporer minima, were associated with very low levels of sunspots and a low solar magnetic field.

There are also major variations in ocean current activity, notably the Pacific Decadal Oscillation (PDO), which appear to be associated with solar cycles and with climate patterns.  This too is not fully recognised by the IPCC.

The current climate scare is driven by the relative rapid rise in mean global temperatures between 1977 and 2000.  When I once challenged the European Commission on their climate obsession, arguing that the changes we have seen were normal and cyclical, they insisted that the recent rise in temperature was so rapid that it must be man-made (how’s that for a non-sequitur?).  But of course half a degree in thirty years is trivial compared to say the Younger Dryas 12,000 years ago, when we saw changes of several degrees in an even shorter period – changes which were clearly not man-made.

But we don’t need to go back 12,000 years.  In the last 150 years we have seen a steady cyclical recovery from the Little Ice Age, apparently leading to a new 21^st Century Optimum (and the word “optimum” is appropriate – warmer temperatures are generally good news).  Superimposed on that we see a sixty-year cycle of thirty (approx) years warming, thirty years cooling.  Such enhanced warmings took place not just in 1977/200, but in 1910/40, and 1860/80.  The rates of warming in all three periods were very similar.  There is nothing exceptional about 1977/2000.  These cycles closely match changes in the PDO.

And in each case they were followed by thirty years or so of static or declining temperatures – leading, as we know, to the Great Global Cooling scare of 1975.  Here at last we have the explanation for the current temperature stasis, which the IPCC is at a loss to explain.  We can expect this stasis or cooling to continue to 2030 or so.  But there’s another factor: astronomers are warning that solar activity seems to be headed for a very quiet period, comparable to those minima in the Little Ice Age.  It could get very cold indeed.  Add to that the fact that we’re 12,000 years into an Interglacial, and that interglacials typically last around 12,000 years, and maybe we should worry not about Global Warming, but about the next glaciation.  That really will be a climate disaster.

Vahrenholt’s book is packed with hundreds of references to peer-reviewed science (it’s almost comical the way that some green apologists seem to assume that no peer-reviewed science supports the sceptics’ case), so it is not only a well-argued thesis, but a valuable reference source as well.  I’ve been reading The Neglected Sun on my shiny new Kindle that I got for Christmas.  I’d urge you to read it too, but in this case I suspect that the hard copy might be a better deal, as the coloured graphs come out black-and-white on the Kindle Paperwhite.  But before any Warmists out there write to me to tell me that UKIP doesn’t understand the science, please just read Vahrenholt’s book.