Extreme Climate Events Now Measurable. It's Started!

[Eclipse Now]

Scientific American says:

 

Normally, floods of the magnitude now being seen in North Dakota and elsewhere around the world are expected to happen only once in 100 years. But one of the predictions of climate change models is that extreme weather—floods, heat waves, droughts, even blizzards—will become far more common. "Big rain events and higher overnight lows are two things we would expect with [a] warming world," says Deke Arndt, chief of the center's Climate Monitoring Branch. Arndt's group had already documented a stunning rise in overnight low temperatures across the U.S.

 

So are the floods and spate of other recent extreme events also examples of predictions turned into cold, hard reality? Increasingly, the answer is yes. Scientists used to say, cautiously, that extreme weather events were "consistent" with the predictions of climate change. No more. "Now we can make the statement that particular events would not have happened the same way without global warming," says Kevin Trenberth, head of climate analysis at the National Center for Atmospheric Research (NCAR) in Boulder, Colo.

 

That's a profound change—the difference between predicting something and actually seeing it happen. The reason is simple: The signal of climate change is emerging from the "noise"—the huge amount of natural variability in weather.

Normally, floods of the magnitude now being seen in North Dakota and elsewhere around the world are expected to happen only once in 100 years. But one of the predictions of climate change models is that extreme weather—floods, heat waves, droughts, even blizzards—will become far more common. "Big rain events and higher overnight lows are two things we would expect with [a] warming world," says Deke Arndt, chief of the center's Climate Monitoring Branch. Arndt's group had already documented a stunning rise in overnight low temperatures across the U.S. So are the floods and spate of other recent extreme events also examples of predictions turned into cold, hard reality?

 

Increasingly, the answer is yes. Scientists used to say, cautiously, that extreme weather events were "consistent" with the predictions of climate change. No more. "Now we can make the statement that particular events would not have happened the same way without global warming," says Kevin Trenberth, head of climate analysis at the National Center for Atmospheric Research (NCAR) in Boulder, Colo.

 

That's a profound change—the difference between predicting something and actually seeing it happen. The reason is simple: The signal of climate change is emerging from the "noise"—the huge amount of natural variability in weather.

http://www.scientificamerican.com/article.cfm?id=extreme-weather-caused-by-climate-change