Winter's Grip

Comments on today’s front page article in the Globe, “Winter easing its grip on northeast.”

http://www.boston.com/news/weather/articles/2008/12/11/winter_easing_its_grip_on_northeast/

The basic thesis, as confirmed by the observations of the Globe's climate expert Chuck Henderson, who sells outdoor apparel in North Conway, is basically correct. Winters are less harsh than they were in the mid-1960s. The questions remain: how much warmer is it now? Is this a bad thing? What caused this warming? Can we do anything to change it?

Regarding the first question: the UNH scientists claim to observe a 0.8 F rise per decade in the northeastern US. (This morning’s print edition reports the number as an insignificant .08 degrees F. Ooops! The web version has been corrected.) This would appear to be worrisome—if this trend continues across the globe, it would result in a 7.2 degree F rise by 2100—which is upper limit of some IPCC estimates. A few caveats are worth noting:

· the figures represent findings from a tiny part of the globe. Furthermore, the scientists note that northern New England is not experiencing a similar warming trend. They hypothesize it is due to snow cover reflecting the sun’s rays. We have no reason to expect that the globe will follow a similar trend.

· The figures are from the winter months only.

· The warming of the entire 20th century is around 1 degree F, so 0.8 degrees F per decade is abnormal. Climate alarmists believe this is because the slope of the temperature increase has been accelerating—leading to runaway warming, tipping points and all sorts of looming disasters. One could also argue that if we take a longer view, the warming in these 30 years will be averaged out by future cooling periods – like the one we seem to be in since 1998.

· the UNH scientists start their chart in 1965, near the end of a 30 year cooling trend from 1940 to 1970. If they had begun their chart in 1930 the rise per decade would be markedly lower.

· the chart ends in 2005, omitting data from the two abnormally cold winters of 2006 and 2007.

· There’s also a strange caption under the chart in small type: “This chart represents all the data used in the study, but the researchers actually analyzed twelve 30-year increments for their conclusions.” I have no idea what this means. Often the raw temperature data is "corrected" to account for local conditions, which brings in human error to what might seem like objective scientific data recording.