Monday, December 07, 2015

How do the Cumbria floods relate to global warming?

The floods in Cumbria are due to an abnormally heavy rainfall event. The Met Office says that a new record had been set for rainfall over a 48-hour period, with 15.9in (405mm) falling in 38 hours at Thirlmere in Cumbria.

The Met says "just as with the stormy winter of two years ago, all the evidence from fundamental physics, and our understanding of our weather systems, suggests there may be a link between climate change and record-breaking winter rainfall. Last month, we published a paper showing that for the same weather pattern, an extended period of extreme UK winter rainfall is now seven times more likely than in a world without human emissions of greenhouse gases.”

The flooding is consistent with global warming theory, since warmer air can carry, and therefore deposit, more water.

An air mass coming up from the Gulf of Mexico passed over unusually warm Atlantic waters, which gave it added moisture.

The current El Nino is not directly operative, since it should mean colder drier winters in Northern Europe, and warmer, wetter winters in Southern Europe.

Ocean cycles supply the immediate cause of the flooding, but global warming means that the cycles will inevitably become warmer as years go on, since 90% of the heat received by the Earth goes into the oceans.

As ever, we do not say any one event is caused by global warming, but we can say that the warming increases the frequency and intensity of floods, heat-waves and other extreme events.

Nothing is ever "proven" in science, but it sure can disprove theories.

And the lukewarmer/denialist theory that man-made climate change will not have a serious impact on world weather patterns is most certainly disproved and refuted by all the evidence. So far, our changes have increased the global temperature by 0.9*C. The "lukewarmers", who have an undue influence on George Osborne, claim that a 2*C elevation would have only a mild effect on global weather. They are utterly and dangerously wrong. Warmer air means more flooding. Period.

No comments: