Study Finds Extreme Winters Not Due To Global Warming – They Should Have Asked HH Lamb!

By Paul Homewood

 

 http://phys.org/news/2015-03-climate-extreme-winters.html

 

 

A new study has found that cold snaps like the ones that hit the eastern United States in the past winters are not a consequence of climate change. Scientists at ETH Zurich and the California Institute of Technology have shown that global warming actually tends to reduce temperature variability

WUWT has the full detail, but their logic is that, because the poles are expected to warm faster under GHG theory, temperature differentials between high and low latitudes will decrease, and therefore extremes in temperature will become less.

What particularly struck me though was the lead author’s comments about jet stream meridionality, which is claimed to result from Arctic warming, and leads to weather blocking and the cold snaps we have seen in recent winters.

 

 

Just a quick reminder of the difference between zonal and meridional jet stream patterns.

 

http://www.theweatherprediction.com/habyhints/159/

 

Tapio Schneider, professor of climate dynamics at ETH Zurich, who led the study has this to say:

The waviness of the jet stream that makes our day-to-day weather does not change much." Changes in the north-south difference in temperatures play a greater role in modifying temperature variability.

 

None of this would come as any surprise to HH Lamb, who had this to say in his book, “Climate, History and The Modern World”, about what was know as the Little Cooling period between 1940 and 1980. (Lamb’s book was published in 1982).

 

ANOTHER TURNING POINT

Over the years since the 1940’s, it has become apparent that many of the tendencies in world climate which marked the previous 50 to 80 years or more have either ceased or changed…. It was only after the Second World War that the benign trend of the climate towards general warming over those previous decades really came in for much scientific discussion and began to attract public notice.

 

VARIABILITY INCREASES

Such worldwide surveys as have been attempted seem to confirm the increase of variability of temperature and rainfall [since 1950].’’

In Europe, there is a curious change in the pattern of variability: from some time between 1940 and 1960 onwards, the occurrence of extreme seasons – both as regards temperature and rainfall has notably increased.

 

These variations, perhaps more than any underlying trend to a warmer or colder climate, create difficulties for the planning age in which we live. They may be associated with the increased meridionality of the general wind circulation, the greater frequency of blocking, of stationary high and low pressure systems, giving prolonged northerly winds in one longitude and southerly winds in another longitude sector in middle latitudes.

Over both hemispheres there has been more blocking in these years… The most remarkable feature seems to be the an intensification of the cyclonic activity in high latitudes near 70-90N, all around the northern polar region. And this presumably has to do with the almost equally remarkable cooling of the Arctic since the 1950’s, which has meant an increase in the thermal gradient between high and middle latitudes.

 

Lamb, of course, did not need computer models to come to this conclusion. Instead, he used detailed knowledge, developed by himself and others over many years, about how climate works, and actual observations.

It is a sign of just how far backwards climate science has gone when his work is ignored.