There has been much worry that extreme weather is the result of changes in the Arctic. For example: Jennifer Francis, Rutgers University, 25 January 2012.
The “Arctic Paradox” was coined during recent winters when speculations arose that the dramatic changes in the Arctic may be linked to severe snowstorms and cold temperatures in mid-latitudes, particularly along the U.S. east coast and in Europe. Recent studies have illuminated these linkages. Evidence is presented for a physical mechanism connecting Arctic Amplification — the enhanced warming in high northern latitudes relative to the northern hemisphere — with the frequency and intensity of several types of extreme weather events in mid-latitudes, such as droughts, floods, heat waves, and cold spells.
Here is a YouTube video on the issue, the main idea seems to be that changes in the Arctic (supposedly caused by global warming) are changing jet stream patterns in mid-latitudes.
The paper that video is based on is here: http://marine.rutgers.edu/~francis/pres/Francis_Vavrus_2012GL051000_pub.pdf
Now, there’s been a pushback, and “…it is demonstrated that previously reported positive trends are an artifact of the methodology”. Ouch.
Just accepted in GRL: http://onlinelibrary.wiley.com/doi/10.1002/grl.50880/abstract
Revisiting the evidence linking Arctic Amplification to extreme weather in midlatitudes Elizabeth A. Barnes DOI: 10.1002/grl.50880
Previous studies have suggested that Arctic Amplification has caused planetary-scale waves to elongate meridionally and slow-down, resulting in more frequent blocking patterns and extreme weather.
Here, trends in the meridional extent of atmospheric waves over North America and the North Atlantic are investigated in three reanalyses, and it is demonstrated that previously reported positive trends are an artifact of the methodology. No significant decrease in planetary-scale wave phase speeds are found except in OND, but this trend is sensitive to the analysis parameters.
Moreover, the frequency of blocking occurrence exhibits no significant increase in any season in any of the three reanalyses, further supporting the lack of trends in wave speed and meridional extent. This work highlights that observed trends in midlatitude weather patterns are complex and likely not simply understood in terms of Arctic Amplification alone.
UPDATE: Andrew Revkin has a relevant piece today on this issue of attributing climate change to current weather patterns:
Could Climate Campaigners’ Focus on Current Events be Counterproductive?By ANDREW C. REVKIN
This graph is from “Climate Risks: Linking Narratives to Action,” an important new essay in the Stanford Social Innovation Review on the gap between major environmental groups’ messaging on human-driven global warming and the focus of their programs and spending. The message these days has become all about extreme events, from the Frankenstorm to intense droughts, but the programs remain locked mainly on strategies for curbing the flow of greenhouse gases, according to the authors, Amy Luers, Carl Pope and David Kroodsma. Please read the piece.
My main concern in viewing the graph is different. Read more here
One thing that is certain about the focus on current events -vs- future events, is that current events and the claims about what is driving them can be easily observed, studied, and if need be, falsified, as the new paper from Elizabeth A. Barnes aptly demonstrated about Arctic amplification and current weather patterns.
I think the focus on current events could easily be viewed as counterproductive, since claims about current events are much easier to falsify than future events. If your agenda is to make you fearful of current weather as a manifestation of future warming, it certainly is counterproductive to have such claims falsified in the “here and now” versus in the future where most people have forgotten about them.
I see this as a good thing for climate skepticism. – Anthony