Wednesday, March 4th 2009, 2:25 PM EST
Kyle Swanson and Isaac Held make some odd comments in the Discovery News article (CCNet 3/3/09), which questions where global warming went.
Apparently, the 'radiative forcing' of CO2 will stay in an unknown hiding place for 30 years and then jump out on us! This sounds like an excuse for buying more time for the failing hypothesis which attempts to implicate CO2 as THE driver of climate. They also seem to claim that natural variability largely manifests itself as cooling rather than warming.
Swanson was, of course, a co-author on the 2007 Tsonis et al GRL paper 'A new dynamical mechanism for major climate shifts' in which the authors claimed to be able to explain all the global temperature tendency changes and El Nino variability in the 20th century, without CO2. They go on to say that major climate shifts have occurred or will occur around 1913, 1942, 1978, 2033, and 2072 and they also predicted a 0.2 Celsius cooling between 2005 and 2020 which should be followed by a 0.3 Celsius warming until 2045 or so - then cooling for the rest of the 21st century. The authors also state that, "The standard explanation for the post 1970s warming is that the radiative effect of greenhouse gases overcame shortwave reflection effects due to aerosols [Mann and Emanuel, 2006].
However, comparison of the 2035 event in the 21st century simulation and the 1910s event in the observations with this event, suggests an alternative hypothesis, namely that the climate shifted after the 1970s event to a different state of a warmer climate, which may be superimposed on an anthropogenic warming trend." A new paper from Wang, Swanson and Tsonis, 'The pacemaker of major climate shifts' suggests the North Atlantic Oscillation (NAO) as the 'pacemaker.' The latest paper from Swanson and Tsonis, accepted for publication on 24th February, asks the question 'Has the climate recently shifted?' Their answer is yes it probably has. In 2001/02 climate shifted away from the consistent warming trend for the period 1976/77 to 2001/02. This is set against a background of global CO2 emissions increasing at a rate of 3.5% per year since 2000.
Meanwhile, Nir Shaviv's latest paper finds more evidence of an unknown solar amplification mechanism, where the radiative forcing associated with small changes in Total Solar Irradiance (TSI) over the 11-year solar cycle are multiplied by 5 to 7 times. So, rather than developing a 'hiding place for CO2' hypothesis, we can look to the collective behaviour of known climate cycles such as the Pacific Decadal Oscillation, the North Atlantic Oscillation, the El Nino/Southern Oscillation, and the North Pacific Oscillation, plus poorly understood solar factors as a big part of the explanation for climate change. Of course, this explanation isn't attractive to social engineers or politicians wanting to impose 'green' taxes and restrictions. You can't tax the Sun, which brings us to the subject of falling solar activity.
On 21st December 2006 NASA's David Hathaway was predicting that solar cycle 24 would be bigger than cycle 23. By January 2009 he changed his mind and predicted a smaller cycle 24. Hathaway also predicts a very small cycle 25, and Milivoje Vukcevic claims to have a formula that predicts cycle 26 that will be even lower than cycle 25. In their 2008 GRL paper Weiss et al asked 'For how long will the current grand maximum of solar activity persist?'
The answer was probably not very long, but they couldn't predict the level of the ensuing minimum and they remained loyal to the greenhouse warming 'consensus' by stating that any cooling would be "insignificant compared with the global warming caused by greenhouse gases. "
So, the lack of cycle 24 sunspots continues and the 'grand maximum' of solar activity we enjoyed during the 20th century may be coming to an end. Small changes in the Sun may have much larger effects on climate, and the Pacific Decadal Oscillation (PDO) seems to have entered a cool phase that could last between 21 to 25 years. If the global non-warming since 2002 continues for 30 years as Kyle Swanson suggests, then we have to consider the possibility that, rather than going into hiding, CO2 isn't the all powerful climate driver that some would have us believe.
Tsonis, Anastasios A.; Swanson, Kyle; Kravtsov, Sergey, A new dynamical mechanism for major climate shifts', Geophys. Res. Lett., Vol. 34, No. 13, 12 July 2007
Wang, G., K. L. Swanson, and A. A. Tsonis (2009), Pacemaker of major climate shifts,' Geophys. Res. Lett., doi:10.1029/2008GL036874, in press.
Swanson, K. L., and A. A. Tsonis (2009), Has the climate recently
shifted?, Geophys. Res. Lett., doi:10.1029/2008GL037022, in
press.(accepted 24 February 2009)
Shaviv, N. J. (2008), 'Using the oceans as a calorimeter to quantify the solar radiative forcing,' J. Geophys. Res., 113, A11101, doi:10.1029/2007JA012989.
Climate Research News:
'Big' Solar Cycle 24 Now Predicted to be Smaller than Cycle 23
Long Range Solar Forecast, 05.10.2006: Solar Cycle 25 peaking around 2022 could be one of the weakest in centuries.
Abreu, J. A., J. Beer, F. Steinhilber, S. M. Tobias, and N. O. Weiss
(2008), For how long will the current grand maximum of solar activity persist?, Geophys. Res. Lett., 35, L20109, doi:10.1029/2008GL035442.