>But as you saw in the last article Carbon Estimates are moving higher as quickly as you can print paper. Maybe thats part of the problem..hahahah
<OK when discussing this stuff you have to laugh or you cry.

ESSAY BY BILL McKIBBEN

To deal with global warming, the first step is to do the numbers.  

CARBONS NEW

Math

HOW IT WORKS.   Before the industrial revolution, the Earth’s atmosphere contained about 280 parts per million of carbon dioxide. That was a good amount—”good” denned as “what we were used to.” Since the molecular structure of carbon dioxide traps heat near the planet’s surface that would otherwise radiate back out to space, civilization grew up in a world whose thermostat was set by that number. It equated to a global average temperature of about 57 degrees Fahrenheit, which in turn equated to all the places we built our cities, all the crops we learned to grow and eat, all the water supplies we learned to depend on, even the passage of the seasons that, at higher latitudes, set our psychological calendars. Once we started burning coal and gas and oil to power our lives, that 280 number started to rise. When we began measuring in the late 1950s, it had already reached the 315 level. Now it’s at 380, and increasing by roughly two parts per million annually. That doesn’t sound like very much, but it turns out that the extra heat that CO₂ traps, a couple of watts per square meter of the Earth’s surface, is

33

 Global warming presents the greatest test humans have yet faced. New technologies and new habits offer some promise, but only if we move quickly and decisively.

enough to warm the planet considerably. We’ve raised the temperature more than a degree Fahrenheit already. It’s impossible to precisely predict the consequences of any further increase in CO₂ in the atmosphere. But the warming we’ve seen so far has started almost everything frozen on Earth to melting; it has changed seasons and rainfall patterns; it’s set the sea to rising.

No matter what we do now, that warming will increase some—there’s a lag time before the heat fully plays out in the atmosphere. That is, we can’t stop global warming. Our task is less inspiring: to contain the damage, to keep things from get­ting out of control. And even that is not easy. For one thing, until recently there’s been no clear data suggesting the point where catastrophe looms. Now we’re getting a better picture—the past couple of years have seen a series of reports indicating that 450 parts per million CO₂ is a threshold we’d be wise to respect. Beyond that point, scientists believe future centuries will likely face the melting of the Greenland and West Antarctic ice sheets and a subsequent rise in sea level of giant proportion. Four hundred fifty parts per million is still a best guess (and it doesn’t include the witches’ brew of other, lesser, green­house gases like methane and nitrous oxide). But it will serve as a target of sorts for the world to aim at. A target that’s moving, fast. If concentra­tions keep increasing by two parts per million per year, we’re only three and a half decades away.

Bill McKibben’s llth book on environmental topics, The Bill McKibben Reader: Pieces from an Active Life, will be published this winter.

34    NATIONAL GEOGRAPHIC • OCTOBER 2OO7

So the math isn’t complicated—bul doesn’t mean it isn’t intimidating. So fai the Europeans and Japanese have even 1 to trim their carbon emissions, and th not meet their own modest targets. Me U.S. carbon emissions, a quarter of the total, continue to rise steadily—earlier thi we told the United Nations we’d be prod 20 percent more carbon in 2020 than we i 2000. China and India are suddenly starti produce huge quantities of CO₂ as welL per capita basis (which is really the only s< way to think about the morality of the situJ they aren’t anywhere close to American 5) but their populations are so huge, andl economic growth so rapid, that they mal( prospect of a worldwide decline in emid seem much more daunting. The Chinese an rently building a coal-fired power plant i week or so. That’s a lot of carbon.

Everyone involved knows what the basid lines of a deal that could avert catastrophe « look like: rapid, sustained, and dramatic d emissions by the technologically advanced^ tries, coupled with large-scale technology! fer to China, India, and the rest of the develi world so that they can power up their emJ economies without burning up their coaL 1 one knows the big questions, too: Are sudd cuts even possible? Do we have the politic^ to make them and to extend them over

The first question—is it even possib usually addressed by fixating on some technology (hydrogen! ethanol!) and i: it will solve our troubles. But the scale problem means we’ll need many strategi years ago a Princeton team made one of assessments of the possibilities. Stephi and Robert Socolow published a paper i detailing 15 “stabilization wedges”-enough to really matter, and for which nology was already available or clear horizon. Most people have heard of them: more fuel-efficient cars, better-b wind turbines, biofuels like ethanol. newer and less sure: plans for building power plants that can separate carbon

 exhaust so it  can be “sequestered” underground. Those approaches have one thing in common:They’re more difficult than simply burning fos-sil fuel. They force us to realize that we’ve already had our magic fuel and that what comes next will be more expensive and more difficult. The price tag for the transition will be in the trillion dollars. Of course, along the way it will create myriad new jobs, and when it’s complete, it may be a much more elegant system. Once built the windmill, the wind is free; you don’t need to guard it against terrorists or build a massive army to control the countries from which it blows.  And since we’re wasting so much energy now, some of the first tasks would be relatively easy.  If we replaced every incandescent bulb that is burned out in the next decade anyplace in the world with a compact fluorescent,we’d make an impressive start on one of the 15 wedges. But in that same decade we’d need to build 400,000 large wind turbines—clearly possible, but only with real commitment. We’d need to follow the lead of Germany and Japan and seriously subsidize rooftop solar panels; we’d need to get most of the world’s farmers plowing their less, to build back the carbon in their soils have lost. We’d need to do everything all at once. As prescedents for such collective effort, people sometimes point to the Manhattan Project tobuild a nuclear weapon or the Apollo Program to put a man on the moon. But those analogies don’t really work. They demanded the intense concentration of money and intelligence on a single small niche in our technosphere. Now we need almost the opposite: a commitment to take what we already know how to do and somehow spread it into every corner of our economies, and indeed our most basic activities. It’s as if NASA’s goal had been to put all of us on the moon.

Not all the answers are technological, of course—maybe not even most of them. Many of the paths to stabilization run straight through our daily lives, and in every case they will demand difficult changes. Air travel is one of the fastest growing sources of carbon emissions around the world, for instance, but even many of us who are noble about changing lightbulbs and happy to drive hybrid cars chafe at the thought of not jetting around the country or the world. By now we’re used to ordering take-out food from every corner of the world every night of our lives— according to one study, the average bite of food has traveled nearly 1,500 miles before it reaches an American’s lips, which means it’s been mari­nated in (crude) oil. We drive alone, because it’s more convenient than adjusting our schedules for public transit. We build ever bigger homes even as our family sizes shrink, and we watch ever

– _£FT: ROBERT CLARK; JORG GREUEL, GETTY IMAGES; ROBERT CLARK; VICTORIA SNOWBER. GETTY IMAGES

CARBON S  NEW MATH     35

bigger TVs, and—well, enough said. We need to figure out how to change those habits.

Probably the only way that will happen is if fossil fuel costs us considerably more. All the schemes to cut carbon emissions—the so-called cap-and-trade systems, for instance, that would let businesses bid for permission to emit—are ways to make coal and gas and oil progres­sively more expensive, and thus to change the direction in which economic gravity pulls when it applies to energy. If what we paid for a gallon of gas reflected even a portion of its huge envi­ronmental cost, we’d be driving small cars to the train station, just like the Europeans. And we’d be riding bikes when the sun shone.

The most straightforward way to raise the price would be a tax on carbon. But that’s not easy. Since everyone needs to use fuel, it would be regressive—you’d have to figure out how to keep from hurting poor people unduly. And we’d need to be grown-up enough to have a real conversation about taxes—say, about switching away from taxes on things we like (employment) to taxes on things we hate (global warming). That may be too much to ask for—but if it is, then what chance is there we’ll be able to take on the even more difficult task of persuading the Chinese, the Indians, and all who are lined up behind them to forgo a coal-powered future in favor of something more manageable? We know it’s possible—earlier this year a UN panel estimated that the total cost for the energy tran­sition, once all the pluses and minuses were netted out, would be just over 0.1 percent of the world’s economy each year for the next quarter century. A small price to pay.

In the end, global warming presents the great­est test we humans have yet faced. Are we ready to change, in dramatic and prolonged ways, in order to offer a workable future to subsequent generations and diverse forms of life? If we are, new technologies and new habits offer some promise. But only if we move quickly and deci­sively—and with a maturity we’ve rarely shown as a society or a species. It’s our coming-of-age moment, and there are no certainties or guar­antees. Only a window of possibility, closing fast but still ajar enough to let in some hope. D

% Warming Trends For more on climate from National Geographic and NPR, visit ngm.com/ climateconnections and npr.org/climateconnections.

How to Cut Emissions

Scientists warn that current C ~ emissions should be cut by at least half over the next 50 yea-s to avert a future global warming disaster. Princeton researchers Robert Socolow and Stephen Pac have described 15 “stabilizatio-wedges” (far right) to realize that goal using existing technologies Each carbon-cutting wedge wou< reduce emissions by a billion me: tons a year by 2057. Adopting a-combination of these strategies that equals 12 wedges could iovm emissions 50 percent.