在许多环境论者看来，我们的世界似乎变得越来越槽。他们列出了一系列我们担忧的问题：自然资源正在枯竭，人口不断增长，粮食越来越少，物种大批灭绝，地球的空气污染和水污染越来越严重。

AFor many environmentalists, the world seems to be getting worse, they have developed hit-list of our main fears: that natural resources are running out; that the population is ever growing, leaving less and less to eat; that species are becoming extinct in vast numbers, and that the planet's air and water are becoming ever more polluted.

但我们只要简单分析一下事实就会发现另外一种情况。首先，自1972年一组科学家出版了《增长的极限》这本书以来，能源和其他自然资源是变得越来越丰富了，而不是越来越少。其次，人均粮食产量比以往任何时候都要高，挨饿的人越来越少。第三，尽管物种的确在灭绝，但未来50年只会有0.7％的物种灭绝，而不是像人们通常所预计的25～50％。最后，大多数环境污染问题或者披夸大其词或者只是暂时的，只是与工业化的早期阶段相联系的，因此解决这些污染问题的最佳方法不是限制经济的发展，而是加速经济的发展。有一种污染，即由于排放温室气体所引起的全球变暖问题，似乎会在未来长期存在，但其总效应却不大可能会带来特别严重的问题。更大的问题反而可能出在应对措施不得力上。

但是民意调查显示，许多人所持的观念认为环境质量标准在下降，造成这种事实与人们观念间的差异的原因大致有四个。

BBut a quick look at the facts shows a different picture. First, energy and other natural resources have become more abundant, not less so, since the book 'The Limits to Growth' was published in 1972 by a group of scientists. Second, more food is now produced per head of the world's population than at any time in history. Fewer people are starving. Third, although species are indeed becoming extinct, only about 0.7%of them are expected to disappear in the next 50 years, not 25-50%, as has so often been predicted. And finally, most forms of environmental pollution either appear to have been exaggerated, or are transient - associated with the early phases of industrialisation and therefore best cured not by restricting economic growth, but by accelerating it. One form of pollution - the release of greenhouse gases that causes global warming - does appear to be a phenomenon that is going to extend well into our future, but its total impact is unlikely to pose a devastating problem. A bigger problem may well turn out to be an inappropriate response to it.

一是科学研究上的偏颇。科学基金主要投入到存在问题的领域。这似乎是一项明智的决策，但是这同样也给人们造成了一种印象，似乎存在许多潜在的问题，而事实并非如此。

第二，环保组织需要得到媒体的注意，也需要支持资金源源不断地流入。因此对于这些团体有时会有夸大其词的情况就不难理解了。比如说，1997年世界自然基金就发布一篇名为《世界森林2／3已不复存在》的新闻稿。而事实上世界森林只减少了20％左右。

CYet opinion polls suggest that many people nurture the belief that environmental standards are declining and four factors seem to cause this disjunction between perception and reality.

尽管这些组织绝大多数都是由无私的人们管理运营的，但他们和其他游说团体有许多共同之处。除非人们对待环境问题的游说活动也像对待其他问题的游说活动一样，持同等的怀疑态度，这种共同之处才不会发挥那么大的作用。比如说，一个贸易组织如果要求降低污染控制标准，这个组织马上就会被认为是在谋私利。而即使对这一污染控制标准的客观审视可能会证明环保组织反对这种污染控制的低标准是弊大于利，这个环保组织仍会被认为是无私的。

另一个使人们印象错位的因素就是媒体的态度。显然，人们对坏消息比对好消息更好奇。新闻和广播就是要提供大众所需要的东西。而这一点可能会导致人们认识上的巨大偏差。1997年和1998年美国受到了厄尔尼诺现象的影响就是一个例子。人们责难这一气候现象使旅游业陷于瘫痪，引起人们的过敏症状，使一个滑雪坡融化造成22人死亡。尽管如此，美国气象协会公告上的一篇文章却认为，尽管厄尔尼诺造成的损失估计有40亿美元。但它带来的收益却高达约190亿美元。这主要得益于冬季气温的升高，这种升温拯救了大约850人的生命，降低了取暖费用，缓解了由于冰峰河流春季融化造成的春洪。

DOne is the lopsidedness built into scientific research. Scientific funding goes mainly to areas with many problems. That may be wise policy, but it will also create an impression that many more potential problems exist than is the case.

第四个因素是个人认知的匮乏。人们担心人均垃圾产生世的日益增多将使世界无处存放垃圾。但是，即使美国的垃圾产生量像以前那样继续增加，即使到2100年美国的人口加倍，全美国在整个21世纪产生的垃圾仍然仅会占到美国领土总面积的1／12,000。

那么全球变暖这一问题怎么样呢?众所周知，二氧化碳的排放导致地球变暖。据估计本世纪气温最高会上升2～3℃，这将带来严重的问题，造成5万亿美元的损失。

E Secondly, environmental groups need to be noticed by the mass media. They also need to keep the money rolling in. Understandably, perhaps, they sometimes overstate their arguments. In 1997, for example, the World Wide Fund for Nature issued a press release entitled: 'Two thirds of the world's forests lost forever'. The truth turns out to be nearer 20%.

尽管人们直觉上认为应当采取一些激进的措施，解决这一可能需要付出高昂代价的问题，但是经济方面的分析表明，采取激进措施削减二氧化碳的排放量，将比采取措施适应温度的上升付出更大的代价。联合图气候变化专家小组的一位主要成员所设计的一项模型表明，如何将2100年时2.1度的气温上升减少到只上升1.9度．换句话说，2094年地球会出现的升温推迟到2100年出现。

所以这并不会防止全球变暖，而只是给了世界6年的宽限期，但仅对美国而言，与解决人人都能获得清洁的饮用水和卫生设施这一世界上最紧迫的健康问题相比，减少二氧化碳排放量要付出更高的代价。而解决了这一健康问题，每年将可以避免200万人死亡。防止5亿人患上严重疾病。要做出有关未来的最佳决定就应当审视一下事实，达一点很关键。过度乐观可能要付出代价，但过度悲观则要付出更大的代价。

F Though these groups are run overwhelmingly by selfless folk, they nevertheless share many of the characteristics of other lobby groups. That would matter less if people applied the same degree of scepticism to environmental lobbying as they do to lobby groups in other fields. A trade organisation arguing for, say, weaker pollution controls is instantly seen as self-interested. Yet a green organisation opposing such a weakening is Seen as altruistic, even if an impartial view of the controls in question might suggest they are doing more harm than good.

GA third source of confusion is the attitude of the media. People are clearly more curious about bad news than good. Newspapers and broadcasters are there to provide what the public wants. That, however, can lead to significant distortions of perception. An example was America's encounter with El Niño in 1997 and 1998. This climatic phenomenon was accused of wrecking tourism, causing allergies, melting the ski-slopes and causing 22 deaths. However, according to an article in the Bulletin of the American Meteorological Society, the damage it did was estimated at US$4 billion but the benefits amounted to some US$19 billion. These came from higher winter temperatures (which saved an estimated 850 lives, reduced heating costs and diminished spring floods caused by meltwaters).

HThe fourth factor is poor individual perception. People worry that the endless rise in the amount of stuff everyone throws away will cause the world to run out of places to dispose of waste. Yet, even if America's trash output continues to rise as it has done in the past, and even if the American population doubles by 2100, all the rubbish America produces through the entire 21st century will still take up only one-12,000th of the area of the entire United States.

ISo what of global warming? As we know, carbon dioxide emissions are causing the planet to warm. The best estimates are that the temperatures will rise by 2-3℃ in this century, causing considerable problems, at a total cost of US$5,000 billion.

JDespite the intuition that something drastic needs to be done about such a costly problem, economic analyses clearly show it will be far more expensive to cut carbon dioxide emissions radically than to pay the costs of adaptation to the increased temperatures. A model by one of the main authors of the United Nations Climate Change Panel shows how an expected temperature increase of 2.1 degrees in 2100 would only be diminished to an increase of 1.9 degrees. Or to put it another way, the temperature increase that the planet would have experienced in 2094 would be postponed to 2100.

KSo this does not prevent global warming, but merely buys the world six years. Yet the cost of reducing carbon dioxide emissions, for the United States alone, will be higher than the cost of solving the world's single, most pressing health problem: providing universal access to clean drinking water and sanitation. Such measures would avoid 2 million deaths every year, and prevent half a billion people from becoming seriously ill. It is crucial that we look at the facts if we want to make the best possible decisions for the future. It may be costly to be overly optimistic - but more costly still to be too pessimistic.