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Archive for September, 2011|Monthly archive page

What are the odds on odd weather?

In Uncategorized on September 14, 2011 at 8:11 pm

So far, this century has been one of escalating heat waves, hurricanes, droughts, ‘snowmageddons’, and floods. In 2011, Mother Nature has managed to turn the mayhem up yet another notch. Is all of this a sign of human-induced global warming, or just random noise?

I plowed through some of the research and asked a few experts to come up with some partial answers. Here is part of the heat wave story:

One link between heat waves and human-induced warming of the atmosphere is simply a matter of statistics. Daily temperatures are distributed like most phenomena, in a bell-shaped curve, with most readings heaped up in the middle—that is, near the average for the date—and the rarer extremes tapering away in both directions as “tails”. As the earth warms, that curve tends to shift to the right, toward higher temperatures, with its right tail leading the way.

Even if the bell curve stays exactly the same shape as it moves, a small shift can lead to many more heat waves. Notes Michael Mann, “The one-degree Celsius increase we have seen in average temperature, for example, appears to be leading to a doubling of the rate at which record-breaking temperatures occur.” That happens because as the curve moves right (a phenomenon firmly linked to greenhouse emissions), the “fatter” part of the tail moves into “extreme” territory.

full story here

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