Northern European and North Atlantic Storminess

Among the highly publicized changes in weather phenomena that are predicted by the IPCC to attend the ongoing rise in the air's CO₂ content are increases in the frequency and severity of nearly all types of storms. This contentious claim is a most appropriate backdrop for the study of Hanna et al. (2008), the findings of whom cut right to its core.

Employing the new dp(abs)24 pressure-variability index, which is defined as "the absolute 24-hourly atmospheric surface pressure variation at a location," the seven scientists studied its temporal variability over the past 160 years via data obtained from "long-running meteorological stations in Denmark, the Faroe Islands, Greenland, Iceland, the United Kingdom, and Ireland," after first showing that the index is "significantly related to wind speed and is therefore a good measure of Atlantic and Northwest European storminess and climatic variation."

Hanna et al.'s results showed, as they describe it, "periods of relatively high dp(abs)24 and enhanced storminess around 1900 and the early to mid-1990s, and a relatively quiescent period from about 1930 to the early 1960s, in keeping with earlier studies." However, they report "there is little evidence that the mid- to late nineteenth century was less stormy than the present, and there is no sign [italics added] of a sustained enhanced storminess signal associated with 'global warming'."

In discussing their findings, the researchers say their analysis "lends a cautionary note to those who suggest that anthropogenic greenhouse warming probably results in enhanced extratropical storminess, as this is indicated neither by our own nor existing published observational results for the northeast Atlantic for the last ~150 years."