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Carl Pope


The Uncertain Summer of Our Discontent

Posted: 08/23/2013 6:20 pm

Climate Change Science

Advance copies of the latest assessment by the global climate science communities have been leaked to Reuters and the New York Times. Their fundamental message -- man caused changes in climate patterns are no longer in even trivial doubt, the certainty is now over 95 percent. This is the conclusion of the 5th report of the IPCC.

But this latest news is unlikely to move politicians, media outlets and businesses to change the way they handle the question of loading up the atmosphere with carbon dioxide and other greenhouse pollutants.

The failure of response is not due to the lack of consequence -- Al Gore's trenchant phrase -- from disrupting the weather. April is no longer the cruelest month. Searing heat waves in the Midwest. Indian Pilgrims dying in blizzards. Persistent rains and cold wiping out Eastern seaboard truck farmers. Devastating floods in Pakistan. The U.S. wildfire bill passing the billion dollar mark for the first time.

We have been warned. The warnings are coming true. The costs are rising. Yet still we dither. What's going on?

One -- only one -- of the ingredients slowing progress may lie in the way climate scientists tried to measure their progress by certainty. Once global certainty came, and too few listened, scientists then sought local certainty -- exactly how would climate disruption change the weather in Chicago? Another, related, comes from the media's trap of asking science "is this hurricane caused by climate change?"

The NYT proclaimed the inability to answer these last questions as ongoing failures of climate science:

The new report also reiterates a core difficulty that has plagued climate science for decades: While averages for such measures as temperature can be predicted with some confidence on a global scale, the coming changes still cannot be forecast reliably on a local scale.

Times Blogger Andy Revkin piled on, "The reality is that efforts to attribute shifts in patterns of extreme weather to the greenhouse effect remain dogged by enormous uncertainty."

But I'm going to argue that the inability to predict with specificity the new climate normal for a particular region, and the uncertainty about what this summer's weather would have been with 50 ppm less CO2 in the atmosphere is not a failure of climate science -- it is a warning about how dangerous climate disruption actually is.

After all, when critics called on Major League Baseball to revoke Barry Bonds' home run titles for steroids use, they did not attempt to calibrate WHICH of his four-baggers were the result of steroids use, nor even determine what his batting average without steroids would have been. They understood that steroids are unacceptable because they change the odds, not because of what they do in any given at bat.

Climate is not a single event -- it is simply statistical summary of weather over time. It is the batting average as opposed to a single at bat. (A separate word for climate as opposed to weather does not exist in many languages for this reason. And for those readers who prefer other metaphors to sports, I'll shift to the kitchen in a moment.) And the concept of "global climate" requires adding up the individual weather which occurs over decades in thousands of locations -- that is why it has been so hard to document how global "climate" already changed.

It is much simpler to understand the risks. Imagine a pot of spaghetti sauce sitting on a stove. The burner is off. Not difficult to predict what the sauce will do -- it will sit. Now imagine the burner is on simmer. The sauce bubbles gently, but you still don't need to worry about anything dramatic. That's the climate the world has enjoyed for the past 10,000 years, the Holocene -- unlike periods of great climate disruption (the advance and retreat of the glaciers, the volcanic winters that created the great extinctions), and in spite of individual tornadoes, floods, cyclones and droughts, human civilization could develop in locations as diverse as the Arctic and the Kalahari. There was time for people (and other species) to figure out how to make a home in a given place because the weather wouldn't change that much. Chicago might have its cold and warm seasons, but it was not going to be Riyadh some winters.

Now turn up the burner, steadily higher, making the sauce hotter. (That's what increasing concentrations of greenhouse pollutants do -- they keep more heat inside the atmosphere. More heat means more energy, molecules moving faster, hitting each other harder -- that's what temperature measures. So an atmosphere with more stored energy is more energized, more violent. Weather is put on steroids.)

At some point the spaghetti sauce will start splattering, and eventually boil over. If you keep turning the burner ever higher, even gradually, you will have a very hard time guessing exactly when the sauce will first burst over its rim, or which way the dangerous splatter will fly.

That doesn't mean that the sauce isn't going to boil over, or burn the cook. And your inability to guess exactly when or how it will boil over should not make you feel safe as you turn the burner ever higher.

Violent weather is bad for people. Unpredictable weather is difficult to get ready for. Cincinnati houses are protected against termites -- termites were always there. Homes in Chicago are not -- because winters were too cold. Given what climate scientists can tell us, should Chicago undertake an expensive and massive termite proofing exercise for its frame buildings? When? How fast? Not knowing is actually harder than knowing.

The fossil apologists have latched on to this search for predictability to question the basic premise of climate risk -- "See, they say, they don't even know if it is going to be drier or wetter in Iowa. How can we believe science so imprecise?"

Weather -- and remember climate is a just your "weather average" -- is very unpredictable. It's the classic unpredictable, "chaotic" phenomenon. (If you tweak it today -- however trivially -- out in the future big changes may result, far larger than your tweak.) As we change fundamentals, like what the atmosphere is made of, how much energy it stores, weather -- and weather's batting average climate -- becomes less predictable. We cannot, and may never be able, to say what the weather in Des Moines will be next August 20. There is therefore no particular reason to believe that climate models will ever be able to tell us with much accuracy what the summer weather will be like in New York in 50 years if we triple concentrations of CO2 over that period.

That imprecision of course, is exactly what we should expect with a chaotic phenomenon. Weather is chaotic, but it has patterns -- attractors mathematicians call them. We don't know how hot Des Moines will be in a year, but we can say what the average temperature and rainfall are likely to be -- those are the attractors, the climate, of the chaotic weather.

What basic science and our own experience are already telling us is that if we keep adding greenhouse pollutants to the atmosphere, we should expect more extreme and violent weather, and less predictable seasons in the places we live. The attractors we are used to will break down. Indeed, once we disrupt the attractors, we really shouldn't expect to know what the new climate, the new attractors will be. (The collapse of the oceanic Gulf Stream would merely be an extremely different version of a new attractor.)

But do we really need more certainty? Would you really keep turning the burner up under a pot as it boiled over because you weren't certain how much time you had to cool it? Or legitimate steroids use until you could calculate just how big an edge they gave their users?

A veteran leader in the environmental movement, Carl Pope spent the last 18 years of his career at the Sierra Club as CEO and chairman. He's now the principal advisor at Inside Straight Strategies, looking for the underlying economics that link sustainability and economic development. Mr. Pope is co-author -- along with Paul Rauber --of Strategic Ignorance: Why the Bush Administration Is Recklessly Destroying a Century of Environmental Progress, which the New York Review of Books called "a splendidly fierce book."

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