一本教會你“做對”題的6級閱讀書 day2 passage3
Passage 3 The Great Pacific Cleanup
太平洋中的超大“垃圾堆” 《新聞周刊》2009-6-18 036
[00:00]The Great Pacific Cleanup
[00:04]Since the Great Pacific Garbage Patch,
[00:08]the world's biggest communal garbage dump,
[00:11]was discovered swirling about 1,000 miles north of Hawaii in 1997,
[00:18]scientists and environmentalists have dared to dream
[00:22]if a cleanup might be possible.
[00:25]Consisting of an estimated 3.5 million tons of garbage
[00:30]and scattered over an area roughly the size of the continental United States,
[00:36]the garbage comes from countries all over the world,
[00:40]most of it flushed through waterways leading to the ocean.
[00:44]Once there, the Pacific rotating system of ocean currents
[00:49]traps the garbage in its final resting place,
[00:52]where it has gathered with wreckage from ships and fishermen,
[00:56]and did widespread destruction to fish and seabirds.
[01:00]Now an unlikely partnership between ocean scientists
[01:04]and the waste-management industry is working on ways to clean up the mess.
[01:09]Earlier this fall, two vessels with the Ocean Voyages Institute in Sausalito,
[01:15]California, headed toward the patch.
[01:19]Most of the scientists on board each ship
[01:22]had previously seen the massive expanse of plastic shallowly submerged
[01:27]over thousands of square miles. It's not densely packed,
[01:31]so you can't walk on it or spot it from a boat,
[01:35]and it's impossible to spot from satellite photos,
[01:38]as much of it remains just below the surface.
[01:42]The project goal for the mission,
[01:45]named Project Kaisei (meaning "ocean planet" in Japanese),
[01:49]was not to measure the size with precision,
[01:53]but to test several methods of extracting the plastic
[01:57]and finding ways to dispose of it properly, ideally through recycling.
[02:02]Testing methods of getting the larger items—plastic chairs,
[02:07]large toys—turned out to be easy.
[02:10]But that still left the much bigger amount of smaller items,
[02:14]like partially broken down toothbrushes, combs, and bottle caps—
[02:18]all of which can't be as easily collected.
[02:23]"The smaller pieces are the ones that are concerning,
[02:26]" says Mary Crowley, Kaisei's project leader and a lifelong ocean explorer.
[02:32]"That's what fish and birds may be eating,
[02:35]and it's terrifying how widely they're being distributed."
[02:39]There's no perfect way to fish it all out of the ocean,
[02:43]especially not without harming ocean creatures in the process.
[02:47]But the crew tested several possible methods. Some were active,
[02:52]involving the dragging of nets to trap and concentrate the garbage to be collected.
[02:58]Others were passive, consisting of large floating receptacles placed
[03:04]near highly concentrated areas and then picked up later to dispose
[03:08]of its contents back on land. The latter, Crowley found,
[03:13]is an applicable and seemingly acceptable way to collect at least the big items.
[03:19]Next comes the difficult task of figuring out
[03:22]what to do with the collected garbage.
[03:25]In his book about the manufacturing process Cradle to Cradle,
[03:30]William McDonough details how disposing of garbage really means
[03:34]just moving it to some other place.
[03:37]The millions of tons of garbage from the Pacific need to go somewhere,
[03:42]and ideally not into landfills, which is why Crowley has a Rolodex
[03:47]of almost a dozen waste-management and recycling companies with
[03:51]which she's collaborating on several possible recycling methods.
[03:57]The leading method is a process called pyrolysis, a form of turning waste into oil
[04:03]or other forms energy without burning. By heating input—in this case,
[04:09]floating drops of plastic—upwards of 550 degrees Fahrenheit in a vacuum,
[04:16]much of the waste breaks down. Further processing then converts the substance
[04:22]to a form of synthetic oil.
[04:24]The good news is that the process can take about 85 percent of the plastics
[04:29]in the Pacific, most of it forms of polyolefin.
[04:33]In some areas of the rotating system of ocean currents,
[04:37]bottle caps are by far the most abundant, primarily
[04:41]because they're manufactured to be denser, and endure longer,
[04:45]than the bottles they seal. According to Pio Goco,
[04:49]a vice president with pyrolysis firm Envion,
[04:53]bottle caps and virtually all forms of polyolefin make excellent material
[04:58]for the pyrolysis process. The oil generator, about the size of a suburban home,
[05:05]could be mounted on a tanker or smaller rig while smaller boats,
[05:10]out collecting waste, continue to feed it.
[05:13]Envion is already testing the process of converting waste
[05:17]to oil in Montgomery County, Md.,
[05:21]which the company says has been a successful demonstration of the technology.
[05:26]"It's a process that drastically changes the dynamics of plastic waste,
[05:31]" says Goco. "When you put it in a landfill, it's gone, and it affects us all.
[05:37]But when you convert it to oil, you can sell it or store it somewhere safer."
[05:42]Still, the process isn't cheap. Each pyrolosis rig costs about $7 million,
[05:49]plus annual maintenance. Advocates argue that the cost can be recovered
[05:55]over several years if the oil that it produces is sold,
[05:59]and even faster if the price of oil rises again. Still,
[06:04]the cost illuminates a less expensive, and perhaps easier, idea.
[06:10]In the mind of Mel Ettenson, editor of the industry publication
[06:16]The Global Plastics Letter, the simplest method is to let the sun's rays
[06:21]break down the plastic with help from highly concentrated UV lights
[06:26]that could be brought to the area.
[06:29]Blasting it with water bombs would accelerate the process.
[06:33]But even if the plastic is gone,
[06:35]its broken-down leftovers won't make the ocean any healthier.
[06:40]To some, the best solution might be to do nothing at all.
[06:45]A massive heap of the world's garbage moving to a relatively isolated
[06:51]part of the globe means that same garbage isn't being buried in landfills
[06:56]and left to potentially pollute land-based water supplies.
[07:00]Ocean advocacy group Oceana sees the north Pacific
[07:05]as one of the most concerning cases of ocean degradation worldwide.
[07:11]"The way to start solving this problem is to stop making it worse,
[07:16]" says Jackie Savitz, campaign director for Oceana.
[07:20]In other words, any discussion about
[07:24]how to clean it up ignores the underlying fact that it's growing larger
[07:28]every day as more garbage is added.
[07:33]According to industry statistics,
[07:35]Americans use 2.5 million plastic bottles every hour,
[07:40]more than half of which end up not being recycled.
[07:45]Environmental groups have focused their anger on the plastics makers,
[07:49]a nearly $400 billion annual industry in the U.S.
[07:54]that continues to grow as plastics become more versatile.
[07:58]The eco talking point is that if plastics makers
[08:03]were to recognize the impacts their products were having on the oceans
[08:08]and global wildlife, they would stop making them.
[08:12]"That's like saying we know cars are bad for the environment,
[08:16]let's get them all off the road now,
[08:19]" says the plastics industry's Ettenson.
[08:22]The problem—as well as the solution—
[08:25]may very well come to a more introspective approach.
[08:29]Kevin Short, co-chair of environmental efforts
[08:32]for the International Association of Plastics Distribution,
[08:36]says that he and colleagues are
[08:40]"organizing to divert plastics away from landfills,
[08:43]" though a process that he calls reverse distribution—
[08:46]a responsible way to collect plastic waste
[08:49]during the manufacturing process that might otherwise end up being buried
[08:54]underground or in the oceans.
[08:56] Even if environmentalists and industry can succeed in changing human behavior,
[09:02]and stop adding garbage to the Pacific patch,
[09:06]its immensity means it's not going anywhere soon.
[09:10]Captain Charles Moore, who discovered the floating garbage in 1997,
[09:16]has already admitted defeat. To him, it would take seemingly endless time
[09:23]and would bankrupt any nation that confronts it. Still Crowley
[09:28]and her team of researchers keep trying. Next year,
[09:32]Kaisei will bring back 100 tons of garbage to process into oil by pyrolysis.
[09:39]But the goal, says Crowley, is to win minds.
[09:43]"We want to show people that the process is indeed possible,
[09:47]and if done right, even profitable."
