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我的一个同事在读电大英语,这是她的一篇作业,希望有哪位会英语的朋友帮忙翻译出来,先在这里表示感谢,我的银子可以随你要。虽然是虚拟的银子。
What Now?
It was probably always too much to believe that human beings would be responsible stewards of the planet. We may be the smartest of all the animals, endowed with exponentially greater powers of insight and abstraction, but we';re animals all the same. That means that we can also be shortsighted and brutish, hungry for food, resources, land--and heedless of the mess we leave behind trying to get them.
And make a mess we have. If droughts and wildfires, floods and crop failures, collapsing climate-sensitive species and the images of drowning polar bears didn';t quiet most of the remaining global-warming doubters, the hurricane-driven destruction of New Orleans did. Dismissing a scientist';s temperature chart is one thing. Dismissing the death of a major American city is something else entirely. What';s more, the heat is only continuing to rise. This past year was the hottest on record in the U.S. The deceptively normal average temperature this winter masked record-breaking highs in December and record-breaking lows in February. That';s the sign not of a planet keeping an even strain but of one thrashing through the alternating chills and night sweats of a serious illness.
The U.N.';s Intergovernmental Panel on Climate Change issued a report on the state of planetary warming in February 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 human activities since 1750 have played a significant role by overloading the atmosphere with carbon dioxide hence retaining solar heat that would otherwise radiate away. The report concludes that while the long-term solution is to reduce the levels of CO2 in the atmosphere, for now we';re going to have to dig in and prepare, building better levees, moving to higher ground, abandoning vulnerable floodplains altogether. When former Vice President Al Gore made his triumphant return to Capitol Hill on March 21 to testify before Congress on climate change, he issued an uncompromising warning: "We do not have time to play around with this."
Some lingering critics still found wiggle room in the U.N. panel';s findings. "I think there is a healthy debate ongoing, even though the scientists who are in favor of doing something on greenhouse gases are in the majority," says Republican Congressman James Sensenbrenner of Wisconsin. But when your last good position is to debate the difference between certain and extra certain, you';re playing a losing hand. "The science," says Christine Todd Whitman, former administrator of the Environmental Protection Agency (epa), "now is getting to the point where it';s pretty hard to deny." Indeed it is. Atmospheric levels of CO2 were 379 parts per million (p.p.m.) in 2005, higher than at any time in the past 650,000 years. Of the 12 warmest years on record, 11 occurred between 1995 and 2006.
So if the diagnosis is in, what';s the cure? A crisis of this magnitude clearly calls for action that is both bottom-up and top-down. Though there is some debate about how much difference individuals can make, there is little question that the most powerful players--government and industry--have to take the lead.
Still, individuals too can move the carbon needle, but how much and how fast? Different green strategies, after all, yield different results. (See "51 Things We Can Do," page 69.) You can choose a hybrid vehicle, but simply tuning up your car and properly inflating the tires will help too. Buying carbon offsets can reduce the impact of your cross-continental travel, provided you can ensure where your money';s really going. Planting trees is great, but in some parts of the world, the light-absorbing color of the leaves causes them to retain heat and paradoxically increases warming.
Even the most effective individual action, however, is not enough. Cleaning up the wreckage left by our 250-year industrial bacchanal will require fundamental changes in a society hooked on its fossil fuels. Beneath the grass-roots action, larger tectonic plates are shifting. Science is attacking the problem more aggressively than ever. So is industry. So are architects and lawmakers and urban planners. The world is awakened to the problem in a way it never has been before. Says Carol Browner, onetime administrator of the EPA: "It';s a sea change from where we were on this issue." Here are the ways that sea is shifting the most:
The Scientists'; Solutions
If the Earth is choking on greenhouse gases, it';s not hard to see why. Global carbon dioxide output last year approached a staggering 32 billion tons, with about 25% of that coming from the U.S. Turning off the carbon spigot is the first step, and many of the solutions are familiar: windmills, solar panels, nuclear plants. All three technologies are part of the energy mix, although each has its issues, including noise from windmills and radioactive waste from nukes.
Biofuels, however, are the real growth science, particularly after President George W. Bush, in his State of the Union address, called for the U.S. to quintuple its production of biofuels, primarily ethanol. That was good news to American corn farmers, who produce the crop from which the overwhelming share of domestic ethanol is made. But the manufacture of corn ethanol is still inefficient: the process burns up almost as much energy as it produces.
A better answer is sugarcane ethanol, which yields eight times the energy it takes to make and provides 40% of all the fuel sold in Brazil. But such ethanol causes environmental problems of its own, as forests are cleared for cane fields. Better still would be to process ethanol from agricultural waste like wood chips or the humble summer grass called switchgrass. The cellulosic ethanol they produce packs more energy than corn ethanol, but it also takes more energy to manufacture. "If you make ethanol by burning coal, you defeat the purpose," says Sarah Hessenflow Harper, an analyst for the advocacy group Environmental Defense.
Until we can dial down the carbon, a more immediate strategy might be to find somewhere to put it all--to sequester it underground. In the same way we store radioactive waste from nuclear reactors, so too could we collect the gaseous CO2 from power plants.
The earth is full of safe, stable places to store gases we don';t want, and scientists know precisely where they are. The natural gas that heats homes, fires stoves and runs factories is found in deep, saline-rich limestone and sandstone cavities, where spongelike pores store gas and help keep it from leaking away. When the energy industry pumps a deposit clean, the chambers stand empty. Not only are the shape and capacity of the cavities mapped, but also in many cases equipment is still on hand that could easily be repurposed from extraction to injection.
The U.S. Department of Energy is funding seven research partnerships to test sequestration technologies. This summer, one of those projects will inject a modest 2,000 metric tons of CO2 into the sandstone subsurface beneath a spread of tomato fields near Thornton, Calif., where it would stay, in effect, forever.
Would that be safe? Carbon dioxide can be lethal, a fact grimly illustrated in 1986 when a giant surge of the stuff bubbled up from Lake Nyos in Cameroon, asphyxiating 1,700 people as they slept. Nonetheless, investigators involved in the Thornton project insist there is little cause for worry. "The fields held oil and gas for millennia," says Larry Myer, an earth scientist with Lawrence Berkeley National Laboratory in Berkeley, Calif., and the project';s director, "so geologically we know they';re going to hold CO2."
Even if researchers master the mechanics of sequestration, they must still develop a way to separate CO2 from power-plant exhaust so that there will be something to stash in the cavities in the first place. There are two promising methods. One is to gasify coal before it';s burned, reducing it to a high-pressure synthetic gas that can be stripped of its carbon, leaving mostly hydrogen behind. The alternative is to pulverize coal as power-plant operators do now but then rely on new hardware to separate the CO2 after burning. Both methods are at least 20 years away from being fully developed, predicts Ernest Moniz, co-director of the M.I.T. Laboratory for Energy and the Environment and a former Under Secretary of the Department of Energy. "We';re very early in the process," he says.
Building a Better Skyscraper
If you want to see what the future of architecture looks like, take a look at the new federal building in San Francisco, but don';t look too long. If you';re like a lot of folks, you won';t much care for it. The glinting, 18-story steel tower jangles badly against the gentle skyline of San Francisco, but it';s beautiful on the inside. There';s the absence of conventional heating and air conditioning in 70% of the floor space. There';s the natural light that fills the workspace during much of the day. There are the windows that actually open and close, and the awninglike fins that filter out heat and glare.
It';s easy to overlook how important a building like this one could be. While the power and auto industries get the bulk of the blame for the planet';s carbon crisis, the business of operating office buildings and homes is responsible for 38% of U.S. CO2 emissions. In the case of offices, mid--20th century technology worked against us, as the development of low-temperature fluorescent lights and high-powered air conditioning made it possible to design sealed structures that you could drop into any climate. "It gave architects the power to design anything, then hand it over to engineers and say, ';Here, you heat and cool it,';" says Gail Brager of the Center for the Built Environment at the University of California, Berkeley.
The new federal building, by contrast, sits lightly on its site and does so using technology that is available. Computer-operated floor vents open and close automatically in response to temperature sensors; interior walls and cubicle partitions are kept to a minimum to increase circulation; automated panels that filter out glare also help air move around the building, creating what the designers call a circulation engine. "Buildings can use passive as well as active energy," says architect Thom Mayne of the firm Morphosis, which designed the building.
Certainly, if you';re going to design a green building, it';s smart to do it in San Francisco, where the generally mild weather makes it easier to let your surroundings set your temperature. But what about a place like New York City, with its 100ºF summers and 10º winters? Bank of America is currently tackling that challenge, with a 945-ft. tower in the heart of Manhattan that will use recirculated heat and natural gas to produce some of its own energy and use it more efficiently. Higher ceilings and insulating glass will reduce temperature changes and maximize available sunlight. The basement will even be equipped with a thermal-control system that will manufacture ice in the evenings, when energy demands are lowest, and use it to cool the building during the day, when power plants are running at peak capacity.
The Pearl River Tower, under construction in Guangzhou, China, is aiming for a net energy footprint of zero by relying on such features as on-site wind turbines and recovery and recycling of condensed water. In Paris, a new tower will rely on wind turbines to provide its heating and cooling for the equivalent of five months of the year. And if you';re a corporation planning a skyscraper, don';t assume you can';t afford to go green. The new buildings typically cost about 5% more to construct than conventional ones but quickly exceed that outlay in energy savings. "I think what we';re doing now will be commonplace in five years," Mayne says.
The Green Company
When a business with more than 7,000 stores, 1.8 million employees and $345 billion in sales changes its ways, it';s hard not to notice. Wal-Mart has made itself the darling of greens with its pledge to install solar panels on many of its stores, switch to hybrid vehicles, conserve water and even buy wild-caught salmon. More important, its mandates are having an incalculable ripple effect through its 60,000 suppliers, which are being asked to join Wal-Mart';s effort to reduce packaging, waste and energy use. And when Wal-Mart asks, there';s little question what the answer will be.
But Wal-Mart is not alone. In January the U.S. Climate Action Partnership, a group that includes some of the biggest corporate players and energy users in the world--Alcoa, BP America, Duke Energy, General Electric, Lehman Brothers, Caterpillar and PG&E--asked the Federal Government to act aggressively on climate change, not least by imposing legal limits on the amount of industrial carbon dioxide emissions. The corporations know there';s a virtue in going green, but they';re also looking for some regulatory certainty before they make massive investments. What';s more, there';s money to be made in the enviro game.
Take General Electric. Its Ecomagination initiative centers on a line of 45 green products, including wind turbines and next-generation jet engines that go easy on the earth but land nicely on the balance sheet. Chairman and CEO Jeffrey Immelt set a goal of generating more than $20 billion in revenue from Ecomagination by 2010, and by 2006 the company had hit the $12 billion mark.
DuPont, which suffered twin hits to both revenue and reputation in the late 1980s and early 1990s, when it had to phase out its production of ozone-destroying chlorofluorocarbons, has made a similar environmental pledge. It sold its Dacron, Lycra and Nylon division--all fossil-fuel-based fabrics--and is concentrating on bio-based materials like Sorona polymer made from starch found in the kernels of corn. DuPont hopes to more than double its revenue from nondepletable resources, to $8 billion by 2015. The company has also cut its greenhouse-gas emissions 72% since 1990 and is aiming for more. That puts DuPont in position to respond nimbly if Washington eventually acts to cap carbon. "We learned that we have to be ahead of legislation," says Linda Fisher, DuPont';s chief sustainability officer, a title of growing significance in corporate America. "That is truer today than it was 20 years ago."
Not surprisingly, some companies talk a green game but don';t really play one. Ford Motor Co. made a big show of performing a $2 billion environmental overhaul of its River Rouge factory in Dearborn, Mich., but still turns out SUVs like the elephantine Expedition, which gets a puny 14 m.p.g. in city driving. Toyota, famous for its hybrid Prius, has nonetheless joined the U.S. Big Three in lobbying Washington against stricter fuel standards.
This kind of environmental posing--greenwashing is the term of art--will not be a viable business strategy in a world transformed by climate change. The smart money is betting on the need for real innovation--clean technology that lowers costs or improves output. Venture capital is increasingly flowing to green start-ups: $474 million in the first three quarters of 2006 in Silicon Valley alone. That';s sparking the interest of everyday investors, who see green technology as--dare they wish it?--the next Internet. Says Ray Lane, a partner at the KPCB venture-capital firm: "If you consider the sheer scale of the problem, I think this is an order of magnitude bigger."
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