Sunday, March 05, 2006

Kristof: In the 'Loop' on Climate Change

Nicholas Kristof teaches a crash course in 'feedback loops' and global warming in today's op ed in the New York Times. Hopefully it will generate lots of 'positive feedback' and action from our 'out of the loop' government, but I wouldn't hold my breath.

Then again, if our 'loopy' leaders continue to look for even 'loopier loopholes' in the science and ignore the looming evidence, we'll all be forced to hold our breath--there simply won't be any clean air left to breath.

By that time, we'll all be 'looped', as in 'f--ked', and there won't be any '12 Step Program' that can help us.

Photo credit: Scientists observe a crack in the Ward Hunt Ice Shelf on the northern shore of Canada’s Ellesmere Island. The crack developed between 2000 and 2002, and allowed the waters of a rare freshwater Arctic lake to empty into the Arctic Ocean. The thinning of this 3,000-year-old shelf—the Arctic’s largest—was caused by the climbing temperatures that are also reducing sea ice. (Photograph copyright V. Sahanatien, Parks Canada)

Warm, Warmer, Warmest
By Nicholas D. Kristof
The New York Times
One of the hottest environmental battles has been over oil drilling in the coastal plain of the Arctic National Wildlife Refuge, but the sad reality is that much of the Arctic plain will probably be lost anyway in this century to rising sea levels.

That should be our paramount struggle: to stop global warming. It threatens not only the Arctic plain, but also low-lying areas around the world with 100 million inhabitants. And it could be accelerating because of the three scariest words in climate science: positive feedback loops.

Bear with me now: a positive feedback loop occurs when a small change leads to an even larger change of the same type. For example, a modest amount of warming melts ice in northern climates. But the bare ground absorbs three times as much heat as ground covered by snow or ice, so the change amplifies the original warming. Even more ice melts, more heat is absorbed, and the spiral grows.

That feedback loop is well understood and part of climate models, but others aren't.

For example, perhaps the biggest single source of uncertainty about whether Lower Manhattan will be underwater in 2100 has to do with the glaciers of Greenland. If Greenland's ice sheet melted completely, that alone — over centuries — would raise the oceans by 23 feet. And those glaciers are dumping much more water into the oceans than they did a decade ago, according to two satellite surveys just published, but the studies disagree on the amounts.

Positive feedback seems to be at work. As a glacier melts a little, the water trickles down to the rock and lubricates the glacier's slide toward the sea. So, because of this and other effects, some of Greenland's glaciers are now, in glacial terms, rocketing toward the sea at 7.5 miles a year.

Here's another positive loop. The Arctic permafrost may hold 14 percent of the world's carbon, but as it melts, some of its carbon dioxide and methane are released, adding to the amount of greenhouse gases. So more permafrost melts.

Likewise, millions of years ago, warming oceans with vast amounts of methane in their depths had great episodes of methane belching, which added to the greenhouse effect then. I don't expect the oceans to burp in the same massive way tomorrow, but if they did, no one would know how to fit those unmannerly oceans into a climate model.

Part of the challenge in modeling climate is that we're already off the charts with greenhouse gases like nitrous oxide, carbon dioxide and methane. "We've driven them out of the range that has existed for the last one million years," noted James Hansen, NASA's top climate expert. "And the climate has not fully responded to changes that have already occurred."

In fairness, there are also negative feedback loops, which could dampen change. For example, warmer temperatures could mean more snow over Antarctica, implying an initial buildup of the Antarctic ice sheet. The added ice could slow global warming and rising sea levels. But a new study just published in Science Express says that the Antarctic ice sheet is already thinning significantly — raising more alarms and casting doubt on that negative feedback.

In any case, it's clear that negative feedback loops in climatology are much less common than positive loops, which amplify change and leave our climate both unstable and vulnerable to human folly.

Still with me?

Look, I know that climate science can be — here's a shock — boring! But it's better for us to slog through it now than for coming generations to slog through the rising waters of, say, Manhattan. It may be more exciting to thump the table about Iraq or torture — or even the preservation of the Arctic National Wildlife Refuge — and those are all hugely important. But global warming may ultimately be the greatest test we face as stewards of our planet. And so far we're failing catastrophically.

"Historians of science will be brutal on us," said Jerry Mahlman, a climate expert at the National Center for Atmospheric Research. "We are right now in a state of deep denial about how severe the problem is. Political people are saying, 'Well, it's not on my watch.' They're ducking for cover, because who's going to tell the American people?"

We know what to do: energy conservation, gas taxes and carbon taxes, more renewable energy sources like wind and solar power, and new (and safe) nuclear power plants. But our political system is paralyzed in the face of what may be the single biggest challenge to our planet.

"Are we an intelligent species or not?" Dr. Mahlman asked. "Right now, the evidence is against it."

Photo credit: Nicholas D. Kristof. (Fred R. Conrad/The New York Times)

Also see:

NASA Earth Observatory


James Aach said...

Another key factor in the global warming debate is the news and opinion feedback. For every good news story on global warming (a story which takes time to tell) there's lots of glitzy 30 second pieces pro- and con, combined with lots of commentators who repeat the glitz they like, followed by more media and public who repeat the glitz the commentators like, and so on....

I may have mentioned the following before: One issue touched on in the article is nuclear power. Few people understand it, including most of those who comment on it publicly. I would know, as it's been my profession for over twenty years. If you would like an entertaining look of the US nuclear industry and a depiction of what an accident might be like, see My thriller novel "Rad Decision" is posted here and is available at no cost to readers.

"I'd like to see Rad Decision widely read." - Stewart Brand, founder of The Whole Earth Catalog.

The Unknown Candidate said...

James, I agree ... and admit to being guilty as charged. I must say, that '30-second pieces' are a function of our times and are certainly not limited to articles on global warming. We're all somewhat stuck in the "spin" cycle of the information superhighway. With information overload comes a necessity to cut through the extraneous and get to the guts. Unfortunate. But true.

Thanks for the heads up on 'Rad Decision.' Despite your obvious job concerns, I wish you could be more forthcoming about your honest views on nuclear power. Care to share ?

Ken said...

I think global warming is a very serious issue. I worry, though, about the over playing of its consequences. I am not trying to downplay global warming, but Kristof did not give a 100% clear picture of feedback loops. He implied that there are more positive feedback loops than there are negative ones. All science can say is that we know of more positive feedback loops than we do negatives ones. And the actual number of feedback loops does not mater. There does not need to be a 1:1 relationship in the number, only in the strength. You could have a million positive feedbacks that are counter balanced by one negative feedback.

Yes, global warming is serious and is being caused by humans. But it may not be as dire as some descriptions have been. We need to keep an eye on Greenland and Antarctica, we need to start planning now on how we are going to adapt, and we need to fund research on how we might engineer a solution.

The Unknown Candidate said...

Ken, point taken. I agree with you except that, based on the information scientists in the field do know, there appears to be more danger in 'underplaying' the seriousness of the problem than in 'overplaying it.' -- Especially given that the policies of the current administration have alarmingly turned back the clock on environmental protections.

I also believe our goal ought to be to enact aggressive policies that begin to immediately reverse the damages--there are so many things we could be doing right now--rather than merely "keep[ing] an eye" on things and failing to act until it is possibly too late. I'm not one for scare tactics, but I believe enough evidence exists to justify pro-activism.

(If I misinterpreted your comment to be focused more on "how we are going to adapt" to the damages done rather than how we can immediately begin to reverse those damages, I apologize.)

I heard one credible climate scientist (can't remember his name, sorry) say that if we could immediately stop all polution--everything--today, it would still take 100 years to reverse the damages. If that statement is even close to being correct--I'm for implementing protections, funding, and incentives for alternative fuels--starting yesterday.

Also, we should immediately revise the tax code to promote environmental protection; for example, discourage (pollution tax) the purchase of gas-guzzling and polluting vehicles and energy ineffecient technologies and practices while encouraging (environmental tax credits & deductions) the opposite--starting right now.