科学家预言 下世纪气温或创万年新高（科学家预言 下世纪气温或创万年新高的原因）

　　The global climate is more than likely to slip into an unpredictable state with unknown consequences for humansocieties if carbon dioxide emissions continue on their present course, a survey of leading climate scientists has found. 　　The 14 scientists, all experts in their fields of climate research, were asked about the probability of a tipping point being reached some time before 2200 if global warming continued on the course of the worst-case scenarios predicted by the Intergovernmental Panel on Climate Change (IPCC). 　　Nine of the fourteen scientists said that the chances of a tipping point for the high scenario were greater than 90 per cent, with only one saying that the chances were less than 50:50. At current rates of CO2 emissions, the world is on course for following the higher trajectory on global warming suggested by the IPCC. 　　They asked the 14 researchers, who included such climate luminaries as Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany and Tom Wigley of the US National Centre for Atmospheric Research. 　　One question focused on the possibility of a "basic state change" to the climate system "with global consequences persisting over several decades". The scientists were asked whether they thought such a tipping point was likely within the next 200 years based on three different climate change scenarios – low, medium and high. 　　All of the experts agree that in the coming century we are likely to witness an increase in global average temperatures not experienced in the past 10,000 years. However, a tipping point is a more qualitative change to the way the climate system behaves, Dr Allen said. 　　The increase in carbon dioxide emissions over the coming few decades will be crucial in determining the sort of climate that the world will live in by the year 2200. Current CO2 levels, running at about 380 parts per million (ppm), are likely to rise to 1,000 ppm if nothing is done to curb emissions from the burning of fossil fuels suchas oil and coal. 　　一项对知名气候科学家的调查发现，如果二氧化碳排放继续保持目前的进程，全球气候完全有可能陷入不可预料的状态，并给人类社会带来未知的后果。 　　这14名科学家都是各自所在气候领域中的专家。他们被问到，如果全球变暖继续按照政府间气候变化问题研究小组（IPCC）所预言的最糟糕的情形发展，那么在2200年之前的某个时候出现拐点（气候系统的根本改变）的概率有多大。 　　这14名科学家中有9人认为，对于最严重的假想状况，出现拐点的概率大于90%，只有一位科学家认为这一概率低于50%。按照目前的二氧化碳排放速率，世界气候的发展进程将会符合IPCC所推测的气温较高的全球变暖曲线。 　　被调查的科学家包括德国波茨坦气候影响研究所的斯特丹-拉姆斯托夫和美国国家大气研究中心的汤姆-威格利等气候研究领域的名人。 　　有一个问题围绕气候系统出现基本状态改变---并产生持续几十年的全球性后果的可能性。这些科学家被问及，按照气温低、中、高三种不同的气候变化假想状况，他们是否认为这样的拐点有可能在今后200年内出现。 　　所有专家一致认为，下一个世纪我们很可能目睹全球平均气温的上升，这种上升是过去1万年中从未有过的。不过艾伦表示，拐点更多地是气候系统表现方式的质变。 　　今后几十年里二氧化碳排放的增加，对于确定世界到2200年时所处的气候类型具有至关重要的影响。如果不采取任何行动限制燃烧石油和煤炭等矿物所产生的排放，那么目前的二氧化碳浓度水平--- 大约是380ppm（ppm为百万分之一）--- 很可能上升到1000ppm。