破坏环境容易，恢复却很难 把地球表面搞得一团糟是一件非常容易的事情，但是恢复却耗时耗力——大多数的加拿大人已经习惯自己生活在一种快速的节奏中。人们使用移动电话以便能够快速及时的联系。人们使用email以便能够在眨眼之间发送传真和照片。我们选择快餐是因为吃快餐的话可以不用等候。……一旦作出任何决定就想立即看见结果。 http://www.enn.com/news/2004-01-29/s_12569.asp Messing up a planet is easy, fixing it takes time Thursday, January 29, 2004 By David Suzuki Most Canadians are used to life moving at break-neck speed. We carry cell phones so we can be reached instantly. We use email so we can transmit text and photos in the blink of an eye. We eat at fast food chains so we can get our food immediately. We drive everywhere to get there faster. Once we've made a decision, we want results — now. Unfortunately, the rest of life on our planet doesn't work that way. Things take time. Processes evolve over hundreds, thousands, or millions of years. As a result, humanity has no problem messing things up quickly but little patience when it comes to fixing them. A perfect example is the ozone layer. Nearly 20 years ago, scientists discovered a massive hole in the ozone layer, the protective layer of ozone gas high in the atmosphere that helps shield all living things from the Sun's harsh rays. The hole was growing and threatened to cause increased skin cancer in humans and a host of unknown environmental problems. Over the next few years, scientists determined the cause of the problem: a group of chemical compounds called CFCs that were used in solvents, aerosols, and as coolants in refrigeration units and air conditioners. When CFCs find their way up into the stratosphere and react with ultraviolet light, it creates chlorine free radicals, which are potent scavengers of ozone. In an unprecedented move, nations around the world quickly agreed to phase out CFCs and the Montreal Protocol was born. It is a well-known and unqualified success. As one researcher points out in a recent edition of the journal Nature, even schoolchildren today are familiar with the story. Unfortunately, our instant-fix mentality is so ingrained that many people are still confused when stories about the ozone hole continue to appear every year. "Didn't we fix that?" is a common refrain. In fact, the Montreal Protocol is working. CFC production has dropped to near zero levels and the ozone layer seems to be gradually repairing itself. But CFCs can persist in the atmosphere for 50 to 100 years. So some of the CFCs manufactured 40 years ago are still destroying ozone today. It will take decades before the protective layer fully heals. Until then, the size of the hole will fluctuate from year to year. Another class of chemicals that will continue to haunt us for decades, even though a number of them were banned in 2001, are persistent organic pollutants. These toxic chemical compounds, which include PCBs, DDT, and dioxin, are easily transported by air and ocean currents and have found their way into even the most remote regions of the planet. They did not exist 75 years ago, but today traces of these compounds can be found in the bodies of every person on Earth. No one knows what long-term effect these substances are having on our health. As humanity's influence on the environment and natural systems continues to grow, we have to remember that it can take far longer to solve our problems than it does to create them. We cannot just switch a problem off like a remote-control television. Global warming, for example, will not be solved instantly. The carbon dioxide we are pumping into the atmosphere today will stay in our air for several hundred years. Even if we stopped producing heat-trapping gases today, the Earth will continue to warm, and we will continue to have more extreme weather events and other climate-related problems for generations. That's why it's so important to get started now. Our planet cannot be commanded to fix itself. Mother Nature does not have a cell phone. She doesn't use email, and she's not too keen on instant messaging either. She takes her time, and we'd better get used to it because like it or not, we're on her schedule. Take the Nature Challenge and learn more at www.davidsuzuki.org Source: David Suzuki Foundation