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Joel Achenbach on Weather Extremes

In today's Washington Post Joel Achenbach has a smart and nuanced piece on weather extremes and climate change. The attribution of weather events and trends to particular causes is difficult and contested.

Equivocation isn't a sign of cognitive weakness. Uncertainty is intrinsic to the scientific process, and sometimes you have to have the courage to stand up and say, "Maybe."

For Achenbach's efforts he gets called stupid and a tool of the "deniers". Such complaints are ironic given that Achenbach explains how foolish it is to put too much weight on extreme events in arguments about climate change:

the evidence for man-made climate change is solid enough that it doesn't need to be bolstered by iffy claims. Rigorous science is the best weapon for persuading the public that this is a real problem that requires bold action. "Weather alarmism" gives ammunition to global-warming deniers. They're happy to fight on that turf, since they can say that a year with relatively few hurricanes (or a cold snap when you don't expect it) proves that global warming is a myth. As science writer John Tierney put it in the New York Times earlier this year, weather alarmism "leaves climate politics at the mercy of the weather."

There's an ancillary issue here: Global warming threatens to suck all the oxygen out of any discussion of the environment. We wind up giving too little attention to habitat destruction, overfishing, invasive species tagging along with global trade and so on. You don't need a climate model to detect that big oil spill in the Mississippi. That "dead zone" in the Gulf of Mexico -- an oxygen-starved region the size of Massachusetts -- isn't caused by global warming, but by all that fertilizer spread on Midwest cornfields.

Some folks may actually get the notion that the planet will be safe if we all just start driving Priuses. But even if we cured ourselves of our addiction to fossil fuels and stabilized the planet's climate, we'd still have an environmental crisis on our hands. Our fundamental problem is that -- now it's my chance to sound hysterical -- humans are a species out of control. We've been hellbent on wrecking our environment pretty much since the day we figured out how to make fire.

This caused that: It would be nice if climate and weather were that simple.

And the U.S. Climate Change Science Program recently issued a report with the following conclusions:

1. Over the long-term U.S. hurricane landfalls have been declining.

2. Nationwide there have been no long-term increases in drought.

3. Despite increases in some measures of precipitation , there have not been corresponding increases in peak streamflows (high flows above 90th percentile).

4. There have been no observed changes in the occurrence of tornadoes or thunderstorms.

5. There have been no long-term increases in strong East Coast winter storms (ECWS), called Nor’easters.

6. There are no long-term trends in either heat waves or cold spells, though there are trends within shorter time periods in the overall record.

In the climate debate, you would have to be pretty foolish to allow any argument to hinge on claims about the attribution of observed extreme events to the emissions of greenhouse gases. But as we've noted here on many occasions, for some the climate debate is a morality tale that cannot withstand nuance, even if that nuance is perfectly appropriate given the current state of understandings. But given the public relations value of extreme events in the climate debate, don't expect Achenbach's reasoned view to take hold among those calling for action. Like the Bush Administration and Iraqi WMDs, for some folks sometimes the intelligence that you wish existed trumps the facts on the ground.