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mckibben2007 - Introducing a series on Meeting the Climate...

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Unformatted text preview: Introducing a series on Meeting the Climate Challenge. For a close look at one option, biofuels, see ”Green Dreams, ” page 38. Never mind the steam spewing from a coal- fired power plant. The problem is what you can’t see: greenhouse gases, mainly C01. Plants like this generate a quarter of human- kind’s CO2 emissions. MTI'CN EPSYEIN, GEl'fY IMAGES ESSAY BY BILL McIGBBEN Carbon’s Math To deal with global warming, the first step is to do the numbers. HBI'B’S 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” defined 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 19505, 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 C02 traps, a couple of watts per square meter of the Earth’s surface, is 33 Cum-Tight .‘C‘; .«_e. c. 4,. E'Ul'lhfir duplication of this material is not permitted Global warming presents the greatest test humans have yet faced. New technologies and new habits offer some promise, but only it 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 C02 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 get— ting 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, green- house 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 concentra- tions keep increasing by two parts per million per year, we’re only three and a half decades away. Bill McIbeen’s 11th book on environmental topics, The Bill McKibben Reader: Pieces from an Active Life, will be published this winter. 34 NATIONAL GEOGRAPHIC ' OCTOBER 2007 So the math isn’t complicated—but that doesn’t mean it isn’t intimidating. So far only the Europeans and Japanese have even begun to trim their carbon emissions, and they may not meet their own modest targets. Meanwhile, U.S. carbon emissions, a quarter of the world’s total, continue to rise steadily——earlier this year we told the United Nations we’d be producing 20 percent more carbon in 2020 than we had in 2000. China and India are suddenly starting to produce huge quantities of C02 as well. On a per capita basis (which is really the only sensible way to think about the morality of the situation), they aren’t anywhere close to American figures, but their populations are so huge, and their economic growth so rapid, that they make the prospect of a worldwide decline in emissions seem much more daunting. The Chinese are cur— rently building a coal-fired power plant every week or so. That’s a lot of carbon. Everyone involved knows what the basic out— lines of a deal that could avert catastrophe would look like: rapid, sustained, and dramatic cuts in emissions by the technologically advanced coun— tries, coupled with large—scale technology trans- fer to China, India, and the rest of the developing world so that they can power up their emerging economies without burning up their coal Every— one knows the big questions, too: Are such rapid cuts even possible? Do we have the political will to make them and to extend them overseas? The first question—is it even possible?—is usually addressed by fixating on some single new technology (hydrogen! ethanol!) and imagining it will solve our troubles. But the scale of the problem means we’ll need many strategies Three years ago a Princeton team made one of the best assessments of the possibilities. Stephen Pacala and Robert Socolow published a paper in Science detailing 15 “stabilization wedges”——changes big enough to really matter, and for which the tech~ nology was already available or clearly on the horizon. Most people have heard of some of them: more fuel—efficient cars, better-built homes, wind turbines, biofuels like ethanol. Others are newer and less sure: plans for building coal-fired power plants that can separate carbon from the SCVBEANS _. . 1 SOLAR PANEL exhaust so it can be “sequestered” underground. These 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 global transition will be in the tril— lions of 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 you’ve 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 rel— atively easy. If we replaced every incandescent bulb that burned out in the next decade any- place 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 pos— sible, 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 fields less, to build back the carbon their soils have lost. We’d need to do everything all at once. As precedents for such collective effort, people sometimes point to the Manhattan Project to CLOCKWISE FROM TOP LEFT: ROBERT CLARK: JONG GREUEL.GE1TYXMAGES:ROEERT CLARK; VICTORIA SNOWBER. GETTV IMAGES WIND TURBINE COMPACI FLUORESCENT BULB build 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 wfll 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 mari— nated 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 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 progres— sively 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 envi- ronmental 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 tran— sition, 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 great- est 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 deci~ sively—«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 guar- antees. Only a window of possibility, closing fast but still ajar enough to let in some hope. El k Warming Trends For more on climate from National Geographic and NPR, visit ngm.coml dinrateconnections and npr.org/climateconnections. 36 NATIONAL GEOGRAPHIC ' OCTOBER 2007 By 2057 -"" _ W H,‘ +91: Projected emissions of "IS Over am] ppm 16 billion metric tons 0 1 b a . . HOW to cut ° ”“6“ .' ,5 ONE WEDGE ATA IIME 0 l l g. . E m I 33' o n s I Each strategy listed below would. .0 $5 by 2057. reduce annual carbon Scientists warn that current COZ three pnsslltle ,' g? Consequences emissions by a billion "19"“: MM- emissions should be cut by at paths WWW” I " H after 2057 ' ' - o . least half over the next 50 years carbon amtsstens. 0 POSS'D'Q . 5 . : ‘0 temperature rise a to avert a future global warming , ,3 and = . . a disaster. Princeton researchers .0 Atmospheric cop EFFIctEch AND CONSERVATION Robert Socolow and Stephen Pacala f . C?fi“;:'::§:“ .2 lmprove fuel economy cfthe two have described 15 "stabilization MAINTAIN I million (ppm) bullion cars expected on the road ,, . . 0 :2 by 2057 to 60 mpg from 30 mpg. wedges (far right) to realize that Curler“ 0 . . . . rate of i .1 Reduce miles traveled annually goal ustng extstmg technologies. 5,19,95,59 / , per ca, 1,0", 10,000 m 5000 Each carbon—cutting wedge would. : _, ,2 [ncwase efficiency in heating, reduce emissrons by a bllllOI’l metric ; 71 2002219. lightmg, and appliances . ercent. tons a year by 2057. Adopting any v p . . " . .4 Improve coal-fired power plant combination of these strategies efficiency ‘0 60 percent "cm 40 that equals 12 wedges could lower m percent. emissions 50 percent. Q ,' HOLD emissions 9 CARBON CAPTURE AND STORAGE o . 0 3‘ ”day S raw by 7' Introduce systems to ca . ~ pture C02 T da I cutting 3 wedges ~—‘ and store it underground at 800 0 V .0 by 2057,1hen large coal-fired plants or 1.600 Global carbon 3 reduce further naturaligasfired plants. emissions are i i 8 5 41: _ estimatedat I III-IIIII-U'I-IIII-IIIIIIIII-l-I-II‘ + ' ~Use'capturesystemsatcoalA 8 billlon metric ‘. , . ‘ 525 ppm derived hydrogen plants produc- tons a year _ -’ Q. REDUCE emussrons by half ’. mg fuel for a billion cars. ‘ Q. over the next 50 years by ( U 1 _ I c ‘ 1 se cap ure systems In coa - .c. cmmg 4 more wadges’ _ 'I' derived synthetic luel plants pro— ------ ~.lha:n reduce further ducing 30 million barrels a day. 5.. ‘ LOW-CARBON FUELS . Replace 1.500 large coal-fired power _ . plants with natural»gas-fired plants in the past _ ‘ - lSp ace coa y increasmg produc- 50 years b' I I b ' ' _ tron of nuclear power to three times Rising carbon today 5 capacity. EMISSIOUS # RE NEWABLES AND BIOSTORAGE r Increase wind-generated power to 25 times current capacity. -' Increase solar power to 700 times current capacity. : .4 Increase wind power to 50 times New current capacity to make hydrogen . t - II . technologtes or fuel ce cars may be needed after 50 years to lower emissions further to reach a .......... 3.33.1333 35.3 3 (hillicns 0i metric tons a year) 3.7 metric tons of C02 emissions contains a metric ton of carbon ' Increase ethanol biotuel production to 50 times current capacity. About one—sixth of the world‘s cropland would be needed. """"""""""""""""""""""""""""""""""""""""""" zero net level .1 Stop all deforestation. (CO; emlSstons minus C02 A Expand conservation tillage to all naturally absorbed Today 2057; by Earth's land _ and oceans). cropland (normal piowing releases carbon by speeding decomposition of organic matter). SCI-ICES MEET H scenery ”0 SEN“ w uni-u, PIMCIYOH UMVUISIW IWTIED II'OII'I. OAK rum NAI'IONAL mama-r tGlOIJL was» am mm. (was 5" Jon-Dun Ail-1h: £9“an 3v MAM wusm. MGM Am ENERGY CONTENT In a gallon of ethanol compared with a gallon of gasoline Gasoline Ethanol 67% In a gallon of biodiesel compared with a gallon of diesel Diesel Biodiesel 86% SOURCE: U.S. ENERGY lNFORMATlON ADMINlSTFlATlON Corn ethanol 3* ' Cane ethanol Nearly all the ethanol Brazil rivals the US. in in the U.S. is brewed from ethanol production because sugarcane yields 600 to 800 yellow feed corn. Proliferating gallons an acre, twice as ethanol distilleries are already competing for corn with meat much as corn. The stalk is producers, driving up prices. 20 percent sugarwfermented Most ethanol is sold as a to make the alcohol and the waste cane can be burned 'o gasoline additive or, in the Midwest, as E85 (85 percent power the distillery, lowering ethanol, 15 percent gasoline). fossil-fuel use. ' US. PRODUCTION I BRAZIL FRODUCIION 4.86 billion gallons (2006) 3.96 billion gallons (2005) US. PRODUCTION COST BRAZIL PRODUCTION COST $1.09 per gallon $0.87 per gallon I U.S. RETAIL PRICE ‘i.- ll illnrl IIII‘,’ f'liLl -'l I BRAZIL RETAIL PRICE (til-Pl galll'll'l, JilltP. I’im?) Gasoline EthanoltEBS) Gasoline (25%athanol) Ethanol 32.5.2: '- W l {$331 I lea _fl To get energy equivalent To get energy equivalent of a gallon of gasoline of a gallon of gasoline | ENERGY BALANCE I ENERGY BALANCE Fossil—fuel energy used Fossil-fuel energy used to make the fuel (input) to make the fuel (input) compared with the energy tzornpared With the energy in the fuel (output) ‘ m the fuel (output) Sugarcane Com ethanol ethanol 1 1.3 1 - 8 l GREENHOUSE GAS EMISSIONS -|H---!Il- ‘iI-III .rII'I ll- v. . I GREENHOUSE GAS EMISSIONS it‘ll ur.li.li:llon and neat Gasoline Corn ethanol Gasoline Sugarcane ethanol 204 16.2 , ‘ 20.4 9 lbslgallon 22% less lbs/gallon 56% less 5i‘lillllfr:'. U k; lII'Afi-‘U! 9;: n5 mini-.7 u s. lm-m:.m-.Ilr.',:l NIGHCTJDN AG! WY HF-‘il wAnll In! I \ assiirilmlijn ”grain r;lli_r-.u_ flflALlnll'q Mime-wan ””3an SflliRCES us out us LI"-1 wrmiuwanm .«slltlllF. lowasmrr llrililllnsnr Biodiesel Cellulosic ethanol Chemically altering plant GERMANY Perennial prairie grasses like switchgrass (left), oils to make biodiesel takes . grown on land unfit for other crops, could less energy than distilling replace up to 13 percent of the w0rld’s oil con— corn into ethanol; the fuel's sumptionaif an efficient way to turn cellulosic main drawbacks are low plant matter into ethanol can be developed. yield and high cost. Ger— many IS the world s leading . U S. FRODUCT'ON producer, relying on canola Still in development; oil; U.S. biodiesel comes no current production from soybeans (right). I SOURCES OF CFLLLILOSiC ETHANOl ' PRODUCT'ON 'N GERMANY 'l' """ ‘-*”“'-"-"' - Agricultural residues (leftover material . . , from crops, such as the stalks, leaves, and 0.5 billion gallons (2005) husks of corn plants) - Forestry wastes like wood chips and sawdust from lumber mills! tree bark .‘ _ - . q -Iil . . . I GERMANY RETA'L PRICE ID“ WNW “MW ‘09 l . Mummpal SOllCl waste (household garbage Diesel Biodiesel and paper products) l 35.15] l'sefii - Paper pulp - Fast‘growing prairie grasses, such as : $56-73 ' switchgrass, whieh require less ‘ _ energy (tractors, terti‘izers, etc.) To 99‘ energy EQU'ValE‘m and can grow on marginal land of a gallon of diesel I ENERGY BALANCE . Fossil—fuel energy used _ ENEHFY BALANCE to make the fuel (input) 59mm“ “ham“ Fossul-fuel energy. used compared with the energy -.- to make the fuel (Input) in the fuel (output) ‘ - |-'|- |:‘I-l .- compared with the energy pin-r.“ v.... .r u- ..i in the fuel (output) Biodiesel 1 2.5 ' GREENHOUSE GAS EMISSIONS Humilitttir'm (”ill |!‘-.r‘,| I- GRFENHOUSE GAS EMISSIONS I1ittiilm ”Jam .m-I imp- Diesel Biodiesel Gasoline Cellulosic ethanol 23“: 7.6 20.4 19 lbs/gallon 68% less lbs/gallon 91% less -_.u in: F". 1-3 um 'I ‘1 1m \.-.--.'r'1|.I-.'.'.:H lI I‘.:.|-|'|."» ‘3It'lllRI’IES ”1‘1 D"E '|:-. I'F‘lt '.'\-'flc|.l'.5'.v.‘-TEHHST-Ti.“ ...
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