We’ve just been waiting for this predictable headline to emerge somewhere, and it happened to pop up in Canada’s CBC News:
h/t to Ron Christie in WUWT Tips and Notes
That “new study” from Rutgers? Not even new. They write:
The 2012 paper says melting Arctic ice is weakening the jet stream. This weakening causes the jet stream to dip further south, which in Canada brings severe cold temperatures for prolonged periods of time.
Um, no. The 2012 study by Jennifer Francis of Rutgers they allude to (but don’t mention) is titled:
Evidence linking Arctic amplification to extreme weather in mid-latitudes
Arctic amplification (AA) – the observed enhanced warming in high northern latitudes relative to the northern hemisphere – is evident in lower-tropospheric temperatures and in 1000-to-500 hPa thicknesses. Daily fields of 500 hPa heights from the National Centers for Environmental Prediction Reanalysis are analyzed over N. America and the N. Atlantic to assess changes in north-south (Rossby) wave characteristics associated with AA and the relaxation of poleward thickness gradients. Two effects are identified that each contribute to a slower eastward progression of Rossby waves in the upper-level flow: 1) weakened zonal winds, and 2) increased wave amplitude. These effects are particularly evident in autumn and winter consistent with sea-ice loss, but are also apparent in summer, possibly related to earlier snow melt on high-latitude land. Slower progression of upper-level waves would cause associated weather patterns in mid-latitudes to be more persistent, which may lead to an increased probability of extreme weather events that result from prolonged conditions, such as drought, flooding, cold spells, and heat waves.
So what is being argued is that somehow, Arctic Amplification (making the Arctic warm faster than the rest of the planet) results is bitterly cold air masses that protrude southward from the circumpolar vortex and linger longer. Note in this forecast panel for the next few days, the cold air outbreak is a regional issue. Would CBC care to say that the warm outbreak over Alaska and the North Atlantic (giving some very nice weather to the UK) is also caused by the same mechanism? If they do, then of course it becomes an unfalsifiable belief, essentially a religion.
Dr. Judith Curry has already taken on this nonsense back in January and writes:
by Judith Curry
In a word, no.
And now for the 2nd question: Does the massive cold air outbreak blanketing much of the U.S. disprove global warming?
Same word: no.
The media are mostly in stupid mode over this one.
Cliff Mass provides a good overview, the punch lines:
The bottom line: the claims that greenhouse warming causes more cold waves like we have seen this week really seems to be without any basis in observational evidence or in theory. The media needs to stop pushing this unsupported argument.
It is SO frustrating that every major weather event causes such claims and counterclaims to be aired, with many media outlets unable to do the minimal research that would allow them to give the public more dependable information.
All this bogus reporting has done substantial damage, with many American’s believing that global warming is already causing our winter weather to become more extreme, while the observational evidence suggests no such thing. One day some sociologists will study this situation and the psychological elements that drove it.
The arguments in favor of an AGW impact on the cold air in the U.S. come from Jennifer Francis (see this previous post).
The bitter winter of 1976-77 in the U.S. with its large polar excursions certainly didn’t have anything to do with global warming then, and it would have been absurd then to make such a claim, it is no less absurd now.
Read the whole paper: 1977v002no04-Wagner (PDF)
The “blocking high” slowed down the progression of the jet stream much like Ms. Francis suggests in her 2012 paper, see this pictorial for what happened in January 2014, much like the pattern of 1977:
Except in 1977, “global warming” was the furthest thing from most scientists and journalists minds at the time.