Haven't we just had some new research that shows just how puny the solar variance is compared to the GHG forced warming? At least you guys have pinned your colours to the mast and given us a set (another set) time period for us to start witnessing the impacts of this 'cool down'. Seeing as we await the next El Nino, after having the 'warmest Nina' on record, this should be interesting as even a moderate Nino (like last time which drove global temps up to record levels) will spike the global temps beyond 98's efforts. Let's just hope the shelf sea permafrosts are not as unstable as they appear to be!!!
During a meeting of the Solar Physics Division of the American Astronomical Society, solar physicists have just announced a prediction that the Sun might enter an extended period of low activity (a â€˜grand minimumâ€™) similar to the Maunder Minimum in the 17th century. In this post I will explore the background of this announcement and discuss implications for Earthâ€™s climate. .... It remains to be seen whether this prognosis turns out to be true (there have been some doubts expressed), but since grand minima of solar activity did occur in the past, it is certainly interesting to explore what effects such a minimum might have on 21st century climate if it did occur. This is precisely the question Stefan Rahmstorf and I investigated in a study published last year (see also our press release. (Earlier estimates for the size of this effect can be found here and here.) In our study we find that a new Maunder Minimum would lead to a cooling of 0.3Â°C in the year 2100 at most â€“ relative to an expected (Modeled) anthropogenic warming of around 4Â°C. (The amount of warming in the 21st century depends on assumptions about future emissions, of course)
A Little Ice Age (Maunder Minimum) is not required. A Dalton Minimum will do -- see the current preview death toll in the Ukraine and Alaska. We should not zig when we should zag. That would be a real "no regrets" policy.
I suggest that this situation obviates application of "Post Normal Science" (PNS). PNS tenets include: Uncertainty (facts uncertain), Dangers (stakes high), Harmful climate change (possibly real), Urgent (decisions urgent), Problem will not go away, Values in dispute and Policy Implications.
The Precautionary Principle cuts both ways, and requires that we stop the assault on fossil fuels. If they are in short supply when we need them, people will freeze.
"... proclaim liberty throughout the land to all its inhabitants ..." -- Leviticus 25:10
Near-Earth variations in the solar wind, measured by the geomagnetic aa index since 1868, are closely correlated with global temperature (r = 0.96; P < 10-7). Geomagnetic activity leads temperature by 4 to 8 years. Allowing for this temperature lag, an outstanding aa peak around 1990 could explain the high global temperature in 1998. After 1990 the geomagnetic aa data show a steep decline comparable to the decrease between 1955 and 1967, followed by falling temperatures from 1961 through 1973 in spite of growing anthropogenic CO2 emissions. This points to decreasing global temperature during the next 10 years.
For hundreds of years, humans have observed that the Sun has displayed activity where the number of sunspots increases and then decreases at approximately 11- year intervals. Sunspots are dark regions on the solar disk with magnetic field strengths greater than 1500 gauss (see Figure 1), and the 11- year sunspot cycle is actually a 22- year cycle in the solar magnetic fi eld, with sunspots showing the same hemispheric magnetic polarity on alternate 11- year cycles. The last solar maximum occurred in 2001, and the magnetically active sunspots at that time produced powerful flares causing large geomagnetic disturbances and disrupting some space- based technology. But something is unusual about the current sunspot cycle. The current solar minimum has been unusually long, and with more than 670 days without sunspots through June 2009, the number of spotless days has not been equaled since 1933 (see users.telenet.be/j.janssens/Spotless/Spotless.html). The solar wind is reported to be in a uniquely low energy state since space measurements began nearly 40 years ago [Fisk and Zhao, 2009]. Why is a lack of sunspot activity interesting? During the period from 1645 to 1715, the Sun entered a period of low activity now known as the Maunder Minimum, when through several 11- year periods the Sun displayed few if any sunspots. Models of the Sunâ€™s irradiance suggest that the solar energy input to the Earth decreased during that time and that this change in solar activity could explain the low temperatures recorded in Europe during the Little Ice Age [Lean et al., 1992].
"Quantifying the Solar Cycle 24 Temperature Decline"
"The green corona emissions point to Solar Cycle 24 being 17 years long, and thus 4.5 years longer than Solar Cycle 23. Using the relationship found by Solheim and his co-authors, that means that the 0.63°C decline for the Northern Hemisphere over Solar Cycle 24 will be followed by a further 0.95°C over Solar Cycle 25. That is graphically indicated thusly, using Figure 19 from the Solheim et al paper:"
Thats a big call from DA...i think he is right with respects to a cooling trend no doubt. But those temps would be a drop that would need to be one of the fastest plunges for who know how long?
And Solar cycle 25 is predicted to be a lot less with respect to those in the maunder minimum, so his calculations are probably quite solid. I guess its another wait and see game, but the trend is getting clearer since 98, once the AMO goes cold at the same time as this is occuring who knows what will happen.
I do not put much emphasis on long term solar cycle forecasts but if 24 & 25 are anywhere near as low as some are predicting and the AMO changes to a negative phase somewhere around 2017-2023 things could get very interesting if not down right scary in a hurry.
On the other hand if we do experience a "landschiedt minimum" and the AMO does change to a negative cycle and temps do not drop there may be something to AGW.