Unit8FocusonGlobalWarming课文翻译综合教程二.doc

Unit 8 Focus on Global Warming
John Weier
Twenty-five years ago if you made a trip to the local library and perused the periodical section for articles on global warming, you’d probably have come up with only a few abstracts from hardcore science journals or maybe a blurb in some esoteric geopolitical magazine. As an Internet search on global warming now attests, the subject has become as rooted in our public consciousness as Madonna2 or microwave cooking.1
Perhaps all this attention is deserved. With the possible exception of another world war, giant asteroid, or an incurable plague, global warming may be the single largest threat to our planet.2 For decades human factories and cars have spewed billions of tons of greenhouse gases into the atmosphere, and the climate has begun to show some signs of warming. Many see this as a harbinger of what is to come.3 If we don’t curb our greenhouse gas emissions, then low-lying nations could be awash in seawater, rain and drought patterns across the world could change, hurricanes could become more frequent, and El Ninos could become more intense.
Our Warming Planet
What has worried many people now is that over the past 250 years humans have been artificially raising the concentration of greenhouse gases in the atmosphere. Our factories, power plants, and cars burn coal and gasoline and spit out a seemingly endless stream of carbon dioxide. We produce millions of pounds of methane by allowing our trash to decompose in landfills and by breeding large herds of methane-belching cattle. Nitrogen-based fertilizers, which we use on nearly all our crops, release unnatural amounts of nitrogen oxide into the atmosphere.
Once these carbon-based greenhouse gases get into the atmosphere, they stay there for decades or longer. According to the Intergovernmental Panel on Climate Change (IPCC) since the industrial revolution, carbon dioxide levels have increased 31 percent and methane levels have increased 151 percent. Paleoclimate readings taken from fossil records show that these gases, two of the most abundant greenhouse gases, are at their highest levels in the past 420,000 years. Many scientists fear that the increased concentrations of greenhouse gases have prevented additional thermal radiation from leaving the Earth. In essence, these gases are trapping excess heat in the Earth’s atmosphere in much the same way that a windshield traps solar energy that enters a car.4
Much of the available climate data appear to back these fears.5 Temperature data gathered from many different sources all across the globe show that the surface temperature of the Earth, which includes the lower atmosphere and the surface of the ocean, has risen dramatically over several decades. Worldwide measurements of sea level show a rise of 0.1 to 0.2 meters over the last century. That’s an increase of roughly 1℃ every 4,000 years. Readings gathered from glaciers reveal a steady recession of the world’s continental glaciers. Taken together, all of these data suggest that over the last century the planet has experienced the largest increase in surface temperature in 1,000 years.
Not surprisingly, many scientists speculate that such changes in the climate will probably result in hotter days and fewer cool days.6 According to the IPCC, land surface areas will increase in temperature over the summer months much more than the ocean. The mid-latitude to high-latitude regions in the Northern Hemisphere — areas such as the Continental United States, Canada, and Siberia — will likely warm the most. These regions could exceed mean global warming by as much as 40 percent.
As far as human health is concerned, those hit hardest will probably be residents of poorer countries that do not have the funds to fend against changes in climate.7 A slight increase in heat and rain in equatorial regions would likely spark an increase in vector-borne diseases such as malaria. More intense rains and hurricanes could cause more severe flooding and more deaths in coastal regions and along riverbeds. Even a moderate rise in sea level could threaten the coastlines of low-lying islands such as the Maldives. All across the globe, hotter summers could lead to more cases of heatstroke and deaths among those who are vulnerable, such as older people with heart problems. The warmer temperatures may also lead to higher levels of near-surface ozone from cars and factories, which would likely cause more perilous air quality days and hospital admissions for those with respiratory problems.
Taking Actions
Fortunately, we can take actions to slow down global warming.8 Global warming results primarily from human activities that release heat-trapping gases and particles into the air. The most important causes include the burning of fossil fuels such as coal, gas, and oil, and deforestation. To reduce the emission of heat-trapping gases like carbon dioxide, methane, and nitrous oxides, we can curb our consumption of fossil fuels, use technologies that reduce the amount of emissions wherever possible, and protect the forests in the world.
We can also do things to mitigate the impacts of global warming and adapt to those most likely to occur,9 e.g., through careful planning and other strategies that reduce our vulnerability to global warming.
But we can’t stop there. We are also advocating policies that will combat global warming over the long term, things like clean cars that run on alternative fuels, environmentally responsible renewable energy technologies, and stopping the clear-cutting of valuable forests.
Clearly, global warming is a huge problem. It will take everyone — governments, industry, communities and individuals working together to make a real difference. Fortunately you can be part of them.

关注全球气候变暖
二十五年前，如果你想去当地的图书馆通过各种期刊搜索关于全球气候变暖的文章的话，很可能你只能找到一些刊登在核心自然科学期刊或非常专业的地理科学杂志上的同类文章的摘要。然而，当今因特网搜索结果表明全球气候变暖，就像麦当娜或微波炉一样，成为所有人都十分关心的话题。
应该说公众对全球气候变暖的关注是很有必要的。除了一些可能的巨大灾害，例如新的世界大战、巨型小行星撞击地球、或是无法治愈的流行疾病等等，全球气候变暖可能是对地球的唯一最大威胁。近几十年来，人类的工厂和汽车向大气中排放了数十亿吨的温室气体，全球气候已经表现出了变暖的趋势。许多人认为这是灾难即将来临的不祥征兆。如果我们不再抑制温室气体的肆意排放，那么那些海拔很低的国家可能被海水淹没，同时多雨和干旱地区的分布也会发生变化，飓风将愈加频繁，而“厄尔尼诺”现象也会愈演愈烈。
地球正在变暖
现在令大多数人担忧的是在过去250年中人类已经人为地增加了大气中温室气体的浓度。我们的工厂、发电厂、汽车燃烧煤和汽油，排放出无穷尽的二氧化碳。我们任由垃圾在废渣填埋池里分解产生甲烷，还大量饲养胃里会产生甲烷气体的家畜，就这样我们人为制造了数百万吨的甲烷气体。我们几乎在所有的农田中都使用以氮为主要元素的化肥，导致超过正常数量的氧化氮进入大气之中。
一旦这些以碳为主要元素的温室气体进入大气层，它们就会存在几十年甚至更久。根据政府间气候变化问题专门研究小组的研究结果，自工业革命以来，空气中二氧化碳的含量增长了31%，甲烷气体的含量甚至增长了151%。从古代化石记录中得到的地质气候资料显示,这两种含量最多的温室气体(二氧化碳和甲烷)居过去42万年之首。许多科学家担心温室气体浓度日益增长会阻碍地球多余热量的散发。实际上，这些气体已经在阻碍地球大气中多余热量的散发，它们阻碍热量散发的原理就和汽车挡风玻璃阻碍太阳热量进入车厢是一样的。
大量可获得的气候数据证明人们的担忧是很有道理的。从全球各地搜集的气温数据显示地球表面温度，包括较低大气层和海洋表面温度，在过去几十年间剧烈上升。全球海平面测量数据也表明在上个世纪中，海平面上升了0.1—0.2米，也就是说海水温度每4000年上升大约1℃。冰川研究数据也显示全球大陆冰川正在逐步消融。总而言之，以上这些数据都表明在过去一个世纪中，地球表面温度上升是近1000年里最快的。
很自然地，许多科学家推测这种种气候变化很可能会导致天气越来越热，凉爽的日子越来越少。根据政府间气候变化问题专门研究小组的研究，地表夏季温度上升幅度将远大于海面温度的上升幅度。北半球中高纬度地——例如美国大陆地区，加拿大和西伯利亚地区——温度上升将最为剧烈。这些地区温度上升幅度将超过全球平均温度上升幅度的40%。
就人类健康而言，那些受到最严重影响的将会是处于贫穷国家的居民，因为他们没有资金来抵御气候变化。在赤道地区,热量和降雨量少许增加就很可能会导致昆虫传播疾病的增加,例如疟疾。海岸地区与河道集中地区的降雨和飓风程度一旦变强，那将会造成更加严重的洪涝灾害和大批人员死亡。甚至海平面只是上升了一点，也会威胁到海拔很低的岛屿国家，例如马尔代夫。在全世界，更加炎热的夏天将导致更多人中暑，并且使那些体弱多病者，例如有心脏疾病的老人失去生命。气温升高也会使近地面的臭氧含量增高，这些臭氧产生自工厂和汽车，并会使空气质量处于危险等级的日子越来越多，而且因为呼吸道疾病住院的人也会越来越多。
采取行动吧
幸运的是，我们可以多种采取措施来减缓全球变暖的进程。全球变暖很大一部分原因是人类活动排放出大量阻碍热量散失的气体和微粒子。其中最重要的原因是大量燃烧化石矿物燃料，例如煤炭、天然气和石油，还有就是滥砍滥伐。为了降低会阻碍热量散失的气体的排放，我们应该限制化石矿物燃料的使用，采取新技术降低所有有害气体的排放，并且保护我们的森林资源。
我们也可以设法减少全球气候变暖带来的负面效应，并且使自己适应可能发生的气候变化，例如，通过详细地规划和其他战略措施减少全球气候变暖带给我们的伤害。
然而这还远远不够。我们还应该通过政策提倡与全球气候变暖打一场持久战，例如，使用替代能源让汽车不再排放温室气体而变的清洁，使用对环境有利的可更新能源技术，并且停止砍伐宝贵的森林。
显而易见，全球气候变暖是个大问题。要解决这个问题，需要每个成员——政府、企业、公众和个人共同努力。幸运的是，你也可以是其中的一员。