Brace for a prolonged cooling folks! Earlier projections were a Dalton Minimum type of cooling -- about 40 years in the 1800s. With the current behavior of the Sun, it looks like a Maundeer Minimum type of cooling -- about 70 yrs in mid-1600 to early 1700 -- might happen.
As a background, see these solar cycles (SC). The flat area starting from 1650 was the Maundeer Minimum where sunspot numbers (SSN) were very very low, almost zero at times. The next low SSNs in the 1800s was the Dalton Minimum.
This is NASA's prediction for the current SC 24 as of March 2009 or nearly two years ago. Peak SSN would be 100 - 110 range. Its March 2008 projection then was a higher SSN peak of 130-140 range.
And here is the actual SSN as of this month. Consequently, NASA (in particular, Dr. David Hathaway) revised downwards its prediction of peak SSN to only 59, to happen sometime in June/July 2013. And that's almost the same level shown during the Maundeer Minimum.
After that solar maximum about 2 1/2 years from now, SSN will fall even lower as a new solar minimum will commence in the transition from SC 24 to SC 25.
That posting in WUWT, expectedly, has attracted many comments. As I write this, there were about 76 comments already. Here are two comments that I like:
(1) John Blake says:
January 18, 2011 at 3:10 pm
For NASA’s information, the Maunder Minimum is conventionally dated over seventy years, from 1645 – 1715, when wolves froze to death in Rhineland forests and wine frosted over in Louis XIV’s goblet in his palace of Versailles. The subsequent Dalton Minimum persisted over forty years from c. 1790 – 1830, marking the final cold-snap of Earth’s 500-year Little Ice Age (LIA) before the precipitate rebound that began c. 1890 – 1939 (fifty years), alternating warming with cooling phases in 1940 – 1979 (forty years), 1980 – 2009 (thirty years), now 2010 – 2029 (twenty years).
On this basis, after about 2030 the global thermostat –apparently there is such a thing– will shake itself to pieces, simultaneously attempting to switch both On and Off. As cyclic wavelengths diminish, so weather-events’ amplitudes and frequencies will increase in proportion. Though chaotic, non-linear, complex dynamic systems are inherently unpredictable in detail (Edward Lorenz, 1960 – ’64), cyclical phenomena in context of long-term secular trends are well-defined.
Yes, global temperatures have been increasing since the LIA petered out from c. 1890; indeed, the thirty-year period 1980 – 2009 represented a cyclical warm-phase. But this involved no anthropogenic CO2 nor any other “forcing mechanism,” and populations now face an end to Earth’s “long summer,” our current 12,250-year Holocene Interglacial Epoch long overdue for a resurgence of median 102,000-year Pleistocene Ice Time.
Green Gangsters such as Briffa, Hansen, Jones, Mann, Trenberth et al. join Luddite sociopaths like Paul Ehrlich, John Holdren, latterly Keith Farnish, in abominating post-Enlightenment industrial/technological civilization and all its works. Over the next several generations, their brutal handiwork will likely result in mega-deaths.
(2) Geoff Sharp says:
January 18, 2011 at 4:48 pm
SC24 has been flat for 12months, it is possible that we have seen the peak of activity already judging by the refusal to get into the normal ramp up, cycle max whenever that happens could be just like today. Its still early days but the revised NASA predictions lead one to think SC24 is a goner.
There are some interesting aspects observed so far. There was a regime shift around June last year where the type of sunspot changed. Large unipolar groups have dominated, these groups by nature have far less F10.7 and EUV output although magnetically they are very strong. The current F10.7 readings are too low considering the current spot activity. We have also witnessed a overall rise in magnetic strength and sunspot darkness over the past 12 months as we head towards solar max, sunspot 1148 yesterday continues this trend which flies in the face of L&P (although Leif will tell you differently)
The SC5/SC24 comparison graph is the one to watch with SC24 looking like it might be weaker than SC5.