Unconventional Climate Wisdom

Two recent articles in American Scientist give evidence that the conventional wisdom behind certain weather-related phenomena is wrong.

The first relates to the shrinking of Mount Kilimanjaro’s glaciers. This article points out that while global warming is real, it plays at most only a minor role in the shrinking of the glaciers. The real culprit seems to be the overall drying out of the atmosphere in the surrounding area, which has been happening since at least the 1880s.

The observations … point to a combination of factors other than warming air—chiefly a drying of the surrounding air that reduced accumulation and increased ablation—as responsible for the decline of the ice on Kilimanjaro since the first observations in the 1880s.

If human-induced global warming has played any role in the shrinkage of Kilimanjaro’s ice, it could only have joined the game quite late, after the result was already clearly decided, acting at most as an accessory, influencing the outcome indirectly.

The other, and to my mind, more startling article shows convincingly that the Gulf Stream is not responsible for Europe’s “unexpectedly” mild climate given its northerly latitude.

As can be seen in the map, the same mild conditions are present on the west coast of North America. This is the case even though the Kuroshio Current, the Pacific analog to the Gulf Stream, turns relatively much further south. The tempering effect is shown to be a result of easterly wind flows across the oceans themselves, unrelated to the supposed warmth of the actual currents.

Because sea-surface temperatures vary less through the seasonal cycle than do land-surface temperatures, any place where the wind blows from off the ocean will have relatively mild winters and cool summers. Both the British Isles and the Pacific Northwest enjoy such “maritime” climates.

Since reading this article, I’ve seen the myth repeated at least a half a dozen times in various places. It’s such a part of conventional wisdom that it gets repeated without challenge.