Global Warming - The Causes - The Perils - The Solutions...

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Unformatted text preview: The Causes - The Perils - The Solutions The Actions: What You Can Do 7+- ?2&4010620 a .I¥i The Tipping Point. Climate change isn’t science fiction, it’s science fact—and it’s already damaging the planet at a pace that’s alarming. Is it too late to reverse or adapt to the changes? o one can sar EXACTLY WHAT IT LOOKS LIKE WHEN a planet takes ill, but it probably looks a lot like Earth. Never mind what you’ve heard about global warming as a slow-motion emergency that would take decades to play out. Suddenly and unexpect- edly. the crisis is upon us. It certainly looked that way in 2007, as some 400,000 In- donesians fled their homes amid rain and flaSh floods of his— toric proportions, only two years after curtains of fire and dust turned the nation's skies orange, thanks to drought-fueled blazes that swept across its islands. It certainly looked that way in 2006, as the atmospheric bomb that was Cyclone Larry—a CatEgOI’Y 5 storm with wind bursts that reached 130 mph.— exploded through northeastern Australia. It certainly looked 14 that way as sections of ice the size of small states calve from the disintegrating Arctic and Antarctic glaciers and ice shelves. Weather disasters have always been with us and surely always will be. But when they hit this hard and come this fast—when the emergency becomes commonplace—something has gone grievously wrong. That something is global warming. The image of Earth as organism—famously dubbed Gaia by environmentalist Iames Lovelock—has probably been over— worked, but that’s not to say the planet can’t behave like a liv- ing thing, and these days, it’s a living thing fighting a fever. From heat waves to storms to floods t0 fires to massive glacial melts, the global climate seems to be crashing around us. Sci— entists have been calling this shot for decades. This is precisely what they have been warning would happen if we continued Gnfi!‘ an!fiscfl—EAmHIJNBERFIREmnM Inn waLnIE—GSI'I'T IIIAGES 6 {WW BHAAS CH— EART ill H D E Fl $1112.: Oll‘. m -_. Afflictions The symptoms of global warming are complex, afiiicring some with flood and others with drought. At left, rising sea levels due to polar melting threaten residents ofmvalu in the South Pacific in 2005. Scientists fear the tiny island nation may vanish beneath the waves. Above, former john Mogill inspects failing crops in Peril-es, Australia, in 2006, where a years—long drought is the worst in the nation’s history pumping greenhouse gases into the atmosphere, trapping the heat that flows from the sun and raising global temperatures. The U.N.’s Intergovernmental Panel on Climate Change is- sued a report on the state of planetary warming in February 2007 that was surprising only in its utter lack of hedging. “Warming of the climate system is unequivocal,” the report stated. What’s more, there is “very high confidence" that hu- man activities since I 750 have played a significant role by over— loading the atmosphere with carbon dioxide (C02), hence re- taining solar heat that would otherwise radiate away. The report concluded that while the long-term solution is to reduce the levels of CO 2 in the atmosphere, for now we’re going to have to dig in and prepare. building better levees, moving to higher ground and abandoning vulnerable floodplains altogether. Environmentalists and lawmakers spent years shouting at one another about whether the grim forecasLs were true, but in the past five years or so, the serious debate has quietly ended. Global warming, even most skeptics have concluded. is the real deal, and human activity has been causing it. if there had been any consolation, it was that the glacial pace of nature would gi-.- :- us decades or even centuries to sort out the problem. But glaciers, it turns out, can move with surprising speed, a 11 Si. so can nature. What few people reckoned on was that glob— al climate systems are booby-trapped with tipping points and fe== 'lback loops, thresholds past which the slow creep of envi- ru .nental decay gives way to sudden and self—perpetuating roll-spec. Pump enough CO2 into the sky, and that last part per mo 'ion of greenhouse gas behaves like the 212th degree Fahr- enheit that turns a pot of hot water into a plume of steam. Melt enough Greenland ice, and you reach the point at which you’re not simply dripping meltwater into the sea but dumping whole glaciers. Studies in 2005 found that several Greenland ice sheets have doubled their rate of slide; in 2006 the journal Science pub— lished a study suggesting that by the end of the century, the world could be locked in to an eventual rise in sea levels of as much as 20 ft. Nature. it seems. has finally got a bellyful of us. “Things are happening a lot faster than anyone predicted," Bill Chameides, chief scientist for the advocacy group Environ— mental Defense and a former professor of atmospheric chem- istry, told TIME in 2006. “The last 12 months have been alarm— ing.” Says Ruth Curry of the Woods Hole Oceanographic Institution in Massachusetts: "The ripple through the scientif- ic community is palpable.” And it's iiuL Lust scientists who are taking notice. Even as na- ture crosses its tipping points, the public seems to have reached its own. For years, p0pular skepticism about climatological sci— ence stood in the way of addressing the problem, but the naysayers—many of whom were on the payroll ot energy companies-"have become an increasingly marginalized breed. in a 2006 Tmelasc NewsiStanford University poll, 85% of re- spondents agreed that global warming probably is happening. Moreover, most respondents said they wanted some action tak~ en. Of those polled, 87 orb believed the government should either encourage or require lowering of power-plant emissions, and 35% thought something should be done to get cars to use less gasoline. Even Evangelical Christians, once among the doubters, 15 Heat wave China's d137, blistering summer of2006 drove people in Qingdao to the beach. In some places, temperatures topped 104017 are demanding action. In February 2006, 86 Christian leaders formed the Evangelical Climate Initiative and called on Con- gress to regulate greenhouse gases. A critical factor in changing the public’s view of the climate crisis was former Vice President Al Gore’s Powerpoint—driven documentary An Inconvenient Truth. Released in May 2006, the film was a surprise smash at the box office. and Gore returned to Washington in March 2007 to testify on global warming to environmental committees in both the Senate and the House. After a prolonged period of denial, even President George W. Bush, no favorite of greens, now acknowledges climate change and boasts of the steps he is taking to fight it. Before heading to Germany in june 2007 for a 6-8 summit meeting-Bush called for a new international accord to fight climate change to be in place by the end of 2008. But most of the measures he supports involve voluntary, not mandatory, emissions controls, rather than the laws with teeth scientists are calling for. At the summit, Bush explicitly rejected mandatory caps on emissions. Is it too late to reverse the changes global warming has wrought? That‘s still not clear. Reducing our emissions output year to year is hard enough. Getting it low enough so that the atmosphere can heal is a multigenerational commitment. Carbon Dioxide and the Poles AS A TINY COMPONENT OF OUR ATMOSPHERE, CARBON DIOXIDE helps warm Earth to comfort levels we are all used to. But too much of it does an awful lot of damage. The gas represents just a few hundred parts per million (p.p.m.) in the overall air blan- ket, but they’re powerful parts because they allow sunlight to streaminbut prevent much of the heat from radiating back out. During the last ice age, the atmoSphere‘s CD2 concentration 16 was just 180 p.p.m., putting Earth into a deep freeze. After the glaciers retreated but before the dawn of the modern era, the to— tal had risen to a comfortable 280 ppm. In just the past centu- ry and a half, we have pushed the level to 38 1 p.p.m., and we’re feeling the effects. Of the 20 hottest years on record, 19 occurred in the 19805 or later. According to climate scientists. 2005 was one of the hottest years in more than a century; so was 2006. It's at the North and South poles that those steambath con- ditions are felt particularly acutely, with glaciers and ice caps crumbling to slush. Once the thaw begins, a number of mech— anisms kick in to keep it going. Greenland is a vivid example. late in 2005, glaciologist Eric Rignot of the jet Propulsion lab— oratory in Pasadena, Calif, and Pannir Kanagaratnam, a re— search assistant professor at the University of Kansas, analyzed data from weather satellites and found that Greenland ice is not just melting but doing so more than twice as fast as in ear— lier years, with 5 3 cu. mi. draining away into the sea in 2005 alone, compared with 22 cu. mi. in 1996. A cubic mile of water is about five times the amount Los Angeles uses in a year. Dumping that much water into the ocean is a very danger— ous thing. Icebergs don’t raise sea levels when they melt be- cause they’re floating. which means they have displaced all the water they’re ever going to. But ice on land, like Greenland’s, is a different matter. Pour that into oceans that are already rising (because warming water expands), and you run the risk of del— uging shorelines. By some estimates, the meltdown of the entire Greenland ice sheet would be enough to raise global sea levels more than 20 ft., swallowing up large parts of coastal Florida and most of Bangladesh. The Antarctic holds enough ice to raise sea levels more than 215 ft. “Ecosystems are usually able to maintain themselves," says CHLOE CHI?“ PHOTOS-Zulu PHISS 'HO‘I’OS— 20 M A PR :55 co Ltd John cunu-.‘ut.lomr aEflnfllFHlC—DEIIT IMABES “Ecosystems are usually able te maintain themselves. But eventually they get pushed te the Emit e'i tee-stanceW Terry Chapin, a biologist and professor of ecology at the Uni- versity of Alaska, Fairbanks. “But eventually they get pushed to the limit of tolerance.” Feedback Loops one or THE seasons THE Loss or THE PLANET‘s ICE coves Is accelerating is that as the poles’ bright white surface shrinks, it changes the relationship of Earth and the sun. Polar ice is so reflective that go% of the sunlight that strikes it simply bounces back into space, taking much of its energy with it. Ocean water does just the opposite, absorbing 90% of the ener- gy it receives. The more energy it retains, the warmer it gets, with the result that each cubic mile of ice that melts vanishes faster than the mile that preceded it. That is what scientists call a feedback loop, and it’s a nasty one, since once you uncap the Arctic Ocean, you unleash an- other beast: the comparatively warm layer of water about 6oo ft. deep that circulates in and out of the Atiantic. “Remove the ice,” says Woods Hole’s Curry, "and the water starts talking to the atmosphere, releasing its heat. This is not a good thing.” A similar feedback loop is melting permafrost, usually de- fined as land that has been continuously frozen for two years or more. There’s a lot of earthly real estate that qualifies, and much of it has been frozen much longer than two years: since the end of the last ice age, or at least 8,000 years ago. Sealed in— side that cryunic time capsule are layers of partially decayed or- ganic matter, rich in carbon. In high—altitude regions of Alaska, Canada and Siberia, the soil is warming and decomposing, re- leasing gases that will turn into methane and C02. That, in turn, could lead to m ore warming and permafrost thaw, says re- search scientist David Lawrence of the National Center for At— mospheric Research (NEAR) in Boulder, Colo. And how much carbon is socked away in Arctic soils? Lawrence puts the figure at zoo gigatons to 800 gigatons. The total human carbon output is only 7 gigatons a year. One result of all that is warmer oceans, and a result of warmer oceans can be. paradoxically, colder continents within a hotter globe. Ocean currents running beMeen warm and cold regions serve as natural thermoregulators, distributing heat from the equator toward the poles. The Gulf Stream, car- rying warmth up from the tropics, is what keeps Europe's cli- mate relatively mild. Whenever Europe is cut off from the Gulf Stream, temperatures plummet. At the end of the last ice age, the warm current was temporarily blocked, and temperatures in Europe fellas much as rn°F, lnclcing the continent in glaciers. What usually keeps the Gulf Stream running is that warm water is fighter than cold water, so it floats on the surface. As it reaches Europe and releases its heat, the current grows denser and sinks, flowing back to the south and crossing under the northbound Gulf Stream until it reaches the tropics and starts to warm again. The cycle works splendidly, provided the water remains salty enough. But if it becomes diluted by freshwater, the salt concentration drops, and the water gets lighter, idling on top and stallingithe current. "in... I. nun-r: 13,, Vii-'31ng A trqflicjum idles motorists in Bangkok,- carbon missions from gasoline-burning cars are one ofthe causes of global wannng 1? From ice to water These two photographs, taken over a span of76 years, illustrate the extent ofglaeid! ice melting in South America. At top, the Upsala Glacier in Patagonia, Argentina, photographed in 1928. At bottom, the valley is shown from the same vantage point in 2004. The glacier has receded into the mountains, and a large lake hasfiirmed in the valley. Scientists say the glacier is retreating 180 ft. peryear In December 2005, researchers associated with Britain’s Na- tional Oceanography Center reported that one component of the system that drives the Gulf Stream has slowed about 30% since 1957. It’s the increased release of Arctic and Greenland meltwater that appears to be causing the problem, introducing a gush of freshwater that's overwhelming the natural cycle. In a warming world, it’s unliker that any amount of cooling that resulted from changing ocean patterns would create a new ice age in Europe. but it could make things very uncomfortable. “The bigworry is that the whole climate of Europe will change," says Adrian Luckrnan, senior lecturcr in geography at the Uni- versity of Wales, Swansea. “We in the UK. are on the same lati- tude as Alaska. The reason we can live here is the Gulf Stream.” Drought as FAST as GLOBAL wammc IS rnausroeumc THE oceans and the ice caps, it’s having an even more immediate effect on land. People, animals and plants living in dry, mountainous regions like the western U.S. make it through summer thanks to snowpack that collects on peaks all winter and slowly melts off in warm months. lately the early arrival of spring and the unusually blistering summers have caused the snnwpack tn melt too early, so that by the time it’s needed, it‘s largely gone. Climatologist Philip Mote of the University of Washington has compared decades of snowpack levels in Washington, Oregon and California and found that they are a fraction of what they were in the 19403, and some snowpacks have vanished entirely. Global warming is tipping other regions of the world into 18 drought in different ways. Higher temperatures bake moisture out of soil faster, causing dry regions that live at the margins to cross the line into full—blown crisis. Meanwhile, El Nifio events—the warm pooling of Pacific waters that periodically drives worldwide climate patterns and has been occurring more frequently in global—warming years—further inhibit pre- cipitation in dry areas of Africa and East Asia According to a re— cent study by NCAR, the percentage of Earth’s surface suffering drought has more than doubled since the 1970s. Hora and Fauna HOT, DRY LAND CAN BE MURDER 0N PLANTS AND ANIMALS, AND both are taking a bad hit. Wildfires in such regions as Indo— nesia, the western U.S. and even inland Alaska have been in— creasing as timberlands and forest floors grow more parched. The blazes create a feedback loop of their own, pouring more carbon into the atmosphere and reducing the number of trees, which absorb CO, and release oxygen. Those forests that don't succumb to fire die in other, slower ways. Connie Millar, a paleoecologist for the U.S. Forest Ser— vice, studies the history of vegetation in the Sierra Nevada. Over the past roe: years, she has found, the forests have shifted their tree lines as much as 100 ft. upslope, trying to escape the heat and drought of the lowlands. Such slow—motion evacua- tion may seem like a sensible strategy, but when you're on a mountain, you can go only so far before you run out of room. “Sometimes we say the trees are going to heaven because they’re walking off the mountaintops,” Millar says. “HEEMPEIIEE m From ice to water These two photographs, taken over a span of76 years, illustrate the extent ofglaciri! ice melting in South America. At top, the Upsala Glacier in Patagonia, Argentina, photographed in 1928. At bottom, the valley is shown fi'om the same vantage point in 2004. The glacier has receded into the mountains, and a large lake has firmed in the valley. Scientists say the glacier is retreating 180 fi. peryear In December 2005, researchers associated with Britain’s Na- tional Oceanography Center reported that one component of the system that drives the Gulf Stream has slowed about 30% since 1957. It’s the increased release of Arctic and Greenland meltwater that appears to be causing the problem, introducing a gush of freshwater that's overwhelming the natural cycle. In a warming world, it’s unlikely that any amount of cooling that resulted from changing ocean patterns would create a new ice age in Europe. but it could make things very uncomfortable. “The big worry is that the whole climate of Europe will change," says Adrian Luckrnan, senior lecturer in geography at the Uni- versity of Wales, Swansea. “We in the UK. are on the same lati- tude as Alaska. The reason we can live here is the Gulf Stream.” Drought as east as GLOBAL WARMING IS TRANSFORMING THE oceans and the ice caps, it‘s having an even more immediate effect on land. People, animals and plants living in dry, mountainous regions like the western US. make it through summer thanks to snowpack that collects on peaks all winter and slowly melts off in warm months. lately the early arrival of spring and the unusually blistering summers have caused the snowpack tn melt too early, so that by the time it’s needed, it’s largely gone. Climatologist Philip Mote of the University of Washington has compared decades of snowpack levels in Washington, Oregon and California and found that they are a fraction of what they were in the 19403, and some snowpacks have vanished entirely. Global warming is tipping other regions of the world into 18 drought in different ways. Higher temperatures bake moisture out of soil faster, causing dry regions that live at the margins to cross the line into full—blown crisis. Meanwhile, El Nifio events—the warm pooling of Pacific waters that periodically drives worldwide climate patterns and has been occurring more frequently in global—warming years—further inhibit pre- cipitation in dry areas of Africa and East Asia According to a re— cent study by NCAR, the percentage of Earth’s surface suffering drought has more than doubled since the 19709. Hora and Fauna HOT, DRY LAND CAN BE MURDER 0N PLANTS AND ANIMALS, AND both are taking a bad hit. Wildfires in such regions as Indo— nesia, the western US. and even inland Alaska have been in— creasing as timberlands and forest floors grow more parched. The blazes create a feedback loop of their own, pouring more carbon into the atmosphere and reducing the number of trees, which absorb CO, and release oxygen. Those forests that don't succumb to the die in other, slower ways. Connie Millar, a paleoecologist for the US. Forest Ser— vice, studies the history of vegetation in the Sierra Nevada. Over the past rot: years, she has found, the forests have shifted their tree lines as much as 100 ft. upslope, trying to escape the heat and drought of the lowlands. Such slow-motion evacua- tion may seem like a sensible strategy, but when you're on a mountain, you can go only so far before you run out of room. “Sometimes we say the trees are going to heaven because they’re walking off the mountaintops,” Millar says. «treatment: at LlI’C s to ifio ally ing )re— . te- . ins ' out) do- in- red. ore ees, ; .ver ; ser— ' tda. El .‘ted l the :ua- III a 3m. use an: fit-f. use - w \ The U.S. is home to less than 5% of the world’s people, yet it produces 25% of the 002 emissions on the planet What About Us? it IS FITTING, Pesnars, rear as me srscrss cauerG ALI. rue problems, we’re suffering the destruction of our habitat ton, and we have experienced that loss in terrible ways. Ocean wa- ters have warmed by a full degree Fahrenheit since 1970, and warmer water is like rocket fuel for typhoons and hurricanes. Two 2005 studies found that in the past 3 5 years the number of Category 4 and 5 hurricanes worldwide has doubled while the wind speed and duration of all hurricanes have jumped 50%. Since atmospheric heat is not choosy about the water it warms, tropical storms could start turning up in some decided— ly nontropical places. “There’s a school of thought that sea sur- face temperatures are warming up toward Canada,” says Greg Holland, senior scientist for man in Boulder. “If so, you're like— ly to get tropical cyclones there, but we honestly don’t know.” What We Can Do so MUCH ENVIRONMENTAL COLLAPSE HAPPENING 1N SCI MANY places at once has at last awakened much of the world, partic- ularly the 141 nations that have ratified the Kyoto treaty to re- duce carbon emissions—an imperfect accord, to be sure, but an accord all the same. The U.S., howeverI which is home to less than 5% of Earth’s population but produces 25% of C02 emis- sions, remains intransigent. Many environmentalists declared the Bush Administration hopeless from the start. and while that may have been premature, it’s undeniable that the White Roi-:5 House’s environmental record—from the abandonment of Kyoto to the President's broken campaign pledge to control carhnn output tn the relaxation nf emission standards—Fins been dismal. Faced with such resistance, many environmental groups have resolved simply to wait out this Administration and hope for something better in 2009. “There are a whole series of things that demonstrate that people want to act and want their government to act.” says Fred Krupp, president of Environmental Defense. Krupp and others believe that we should probably accept that it‘s too late to pre- vent C02 concentrations from climbing to 450 ppm. (or 70 p.p.m. higher than where they are now). From there, however, they hope to stabilize them and start to dial them back down. That goal should be attainable. Curbing global warming may be an order of magnitude harder than, say, eradicating smallpox or putting a man on the moon. But is it moral not to try? We did not so much march toward the environmental precipice as drunkenly reel there, snapping at the scientific scolds who told us we had a problem. The scolds. howeverI knew what they were talking about. In a solar system crowded with sister worlds that either emerged stillborn Like Mercury and Venus or died in infancy like Mars, we’re finally coming to appreciate the knife—blade margins within which life can thrive. For more than a century we’ve been monkeying with those margins. It’s long past time we set them right. - l a'. rest . 1 drawing on on 1870 postcard shows the Rhone Glacier sweeping into Gletsclt, Switzerland; in 2005 the glacier could hardly be seen 19 ...
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Global Warming - The Causes - The Perils - The Solutions...

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