New York Times op-ed columnist Nicholas D. Kristof has spoken out on global warming and what he has to say is a must-read.Kristof strips away the rhetoric and gets right to the science while acknowledging the uncertainties of that science. And doesn’t bash President Bush for his unleaderly passivity on global warming, which at times seems more like denial and has been a drag on the national dialog that is necessary before this potential catastrophe can be addressed.
Kristof’s column is hiding behind the Times’ wretched subscription firewall, but Kiko’s House reprints here it in its entirety because it’s too important to miss.
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 underway 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 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 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, more renewable energy resources 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.”
3 comments:
I would find Mr Kristof's science more persuasive if he didn't lapse into political statements like, "And so far we’re failing catastrophically." Etc. etc.
In the South Island of New Zealand, glaciers in the Southern Alps had been retreating for 50 years or more, which might well be taken as evidence of warming. Now they are advancing again, rapidly, and they are moving faster. The quantity of ice they contain is growing.
There has been speculation in the past that the low-lying Tokelau Islands in the Pacific are in danger of being flooded and will disappear. Yet there is a recent estimate that the Pacific Ocean in that area has risen by half a millimetre, and there are no signs — yet — of its acceleration.
Hardly anyone doubts that the climate is changing. The important disagreement is over whether the change is being caused by mankind — and in the case of New Zealand the digestive systems of the national dairy herd, whose belching and farting of methane gas is the country's biggest contributor to atmospheric change.
The earth has warmed and cooled since the very beginning. Ice Ages are well known and recorded, and in the 13th century there was a warm period of unprecedented agricultural production and progress. There is ample evidence that solar radiation is increasing, and it is believed that this warms the earth's atmosphere.
The question which Mr Kristof and the execrable New York Times seem to think they know how to answer, is whether mankind is the cause of climate change. Right now, that's politics, not science.
It may well be true that driving your SUV will cause grapes to grow in regions now too cold, but there is no proof either way, and no straightforward way to know for sure.
Mr. Bumpkin misses the boat by mile in his atypically strident response.
Of course the earth has warmed and cooled since the beginning of time. But just because Mr. Bumpkin's glaciers are behaving in a politically correct manner for him and the denial crowd doesn't mean that other glaciers are. To blow off Kristoff's call for a dialog on global warning because he works for an "execrable" paper and "lapses" into political statements is dumb. There is substantial non-partisan science that shows that we may be headed for catastrophe. To heap scorn on someone who suggests that we need to at least talk about global warming is itself so much methane gas.
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