If you haven't noticed, it's been rather cold lately (except in the Pacific Northwest where it's been rather warm). In fact, the globe has cooled or at least stopped warming for about the past decade. And now scientists have an explanation, sort of. In the Wall Street Journal today it is explained:
[T]he concentration of water vapor in the stratosphere has dropped about 10% in the past decade, triggered by unexplained cooler temperatures at certain high altitudes above the tropics. The study concludes that in the last decade the decline in water vapor slowed the rate of rising temperatures by about 25%, thus partly negating the heat-trapping effect of increasing greenhouse gases such as carbon dioxide and methane.
The key phrase there is "unexplained cooler temperatures at certain high altitudes above the tropics." Scientists still don't know what caused those cooler temperatures, called "cold point" temperatures. But scientists are still grasping at straws to explain it all:
The overall picture is still far from complete. Water vapor's role may be important, but "it doesn't rule out other contributing factors," such as changes in ocean currents and solar activity, says Dr. Solomon.
Nor do current warming models fully account for all the complexities of water-vapor shifts in the stratosphere. And scientists have yet to pin down why cold point temperatures in the tropics fell in the past decade.
The models didn't predict the past decade's cooling. Changes in ocean currents and solar activity could be to blame. If the models can't predict what's going to happen today how can they be trusted to predict what's going to happen 90 years from now? They can't.
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