Update and brief review below by Ryan Maue…
From Reuters Alert Net: Colder winters possible due to climate change-study
* Colder winters possible in northern regions
* Shrinking sea ice causes airstream anomalies
* Finding does not conflict with global warming
BERLIN, Nov 16 (Reuters) – Climate change could lead to colder winters in northern regions, according to a study by the Potsdam Institute for Climate Impact Research on Tuesday.
Vladimir Petoukhov, lead author of the study, said a shrinking of sea ice in the eastern Arctic causes some regional warming of lower air levels and may lead to anomalies in atmospheric airstreams, triggering an overall cooling of the northern continents.
“These anomalies could triple the probability of cold winter extremes in Europe and northern Asia,” he said. “Recent severe winters like last year’s or the one of 2005/06 do not conflict with the global warming picture but rather supplement it.”
h/t to WUWT readers e.c cowan and Michael P.
Ryan Maue Update: It took me some doing to find this study in the Journal of Geophysical Research Atmospheres. The study is fine as constructed, but why is this worthy of a press release?
This study employs a climate model to determine the sensitivity of the atmospheric circulation to sea-ice concentration. The ECHAM5 model is used with T42 spectral resolution (that is 2.8×2.8 degree longitude/latitude spacing !!!) and 19 vertical levels. This is about the model setup of NCEP’s operational weather forecasting models in the 1980s. Six “simulations” (or scenarios) were performed of 100 years duration with differing sea-ice concentration in the Barents-Kara (B-K) sector. Their results are therefore 100-year averages obtained from the simulations.
The conclusions are not conclusive at all but very equivocal in nature. This is contrary to the press release. Since European winter climate is strongly controlled by a host of climate modes such as ENSO, NAO, AO, PDO, etc., their study cannot include the non-linear interplay between the actors and their sea-ice concentration scenarios. This is a very idealized experiment with results that are very preliminary when it comes to relating to the true atmosphere. There is no analysis of the 2005/2006 winters to determine if indeed the sea-ice mechanism was responsible for the cooler winter.
The study’s conclusions with respect to future climate change are very speculative to say the least. This is the case with many of these types of climate scenario experiments. Step one is to find a phenomenon that goes against the AGW consensus: here it is a cold winter in the Northern Hemisphere. Step two is to construct an experiment which explains the phenomena in the context of AGW. Step three is to connect step 2 to step 1 and issue a press release containing facts not in evidence.