经济学人下载:气候变化 最终难道是个好消息?

Science and Technolgy
科技

Climate change
气候变化

Good news at last?
最终难道是个好消息？

The climate may not be as sensitive to carbon dioxide as previously believed
气候对二氧化碳的敏感性，可能没有原来认识的那样强

CLIMATE science is famouslycomplicated, but one useful number to keep in mind is "climatesensitivity". This measures the amount of warming that can eventually beexpected to follow a doubling in the atmospheric concentration of carbondioxide. The Intergovernmental Panel on Climate Change, in its most recentsummary of the science behind its predictions, published in 2007, estimatedthat, in present conditions, a doubling of CO2would cause warming of about 3°C, with uncertainty of about a degree and a halfin either direction. But it also says there is a small probability that thetrue number is much higher. Some recent studies have suggested that it couldbe as high as 10°C.
气候科学的复杂是出了名的，但"气候敏感度"是已知的一个非常实用、必须被谨记的指标。这一指标用于衡量由于大气中二氧化碳的浓度增长一倍而引起的温度变化总量。最近一份联合国政府间气候变化专门委员会提交的研究预测报告公布于2007年。该报告预测，按照目前的情况，二氧化碳浓度增加一倍将会导致温度上升3°C，不确定度为±1.5°C。同时报告指出，还存在一种很小可能性，实际的数字也许比这个值要高很多。一些近期的研究认为这个指标高达10°C。

If that were true, disaster beckons. But apaper published in this week's Science,by Andreas Schmittner of Oregon State University, suggests it is not. In DrSchmittner's analysis, the climate is less sensitive to carbon dioxide than wasfeared.
如果这个情况是可靠的，大限将至。但本周，来自Oregon State University的Andreas Schmittner刊登在《科学》杂志上的一篇论文认为，事实并不是这样的。在Schmittner博士的研究中，气候对二氧化碳的敏感性并没有达到大众所担心的水平。

Existing studies of climate sensitivitymostly rely on data gathered from weather stations, which go back to roughly1850. Dr Schmittner takes a different approach. His data come from the peak ofthe most recent ice age, between 19,000 and 23,000 years ago. His group is notthe first to use such data (ice cores, fossils, marine sediments and the like)to probe the climate's sensitivity to carbon dioxide. But their paper is themost thorough. Previous attempts had considered only small regions of theglobe. He has compiled enough information to makea credible stab at recreating the climate of the entire planet.
现有的关于气候敏感性的研究大都依赖于那些回述至19世纪50年代的气象站检测数据。Schmittner博士选择了非传统的途径。他的数据来自最近一次冰河期的高峰，一个距今19000年至23000年间的年代。他的团队并非第一个采用这种类型数据（来自冰核，化石，海洋沉积物或其他类似情形）来研究气候对于二氧化碳敏感性的团队。但原先做这种尝试的研究团队仅收集全球很小一部分地区的数据。而Schmittner博士编制了足够多的信息以制作一个可以信赖的模型用于预计整个地球的气候变化。

The result offers that rarest of things inclimate science-a bit of good news. The group's most likely figure for climatesensitivity is 2.3°C, which is more than half a degree lower than the consensusfigure, with a 66% probability that it lies between 1.7° and 2.6°C. More importantly,these results suggest an upper limit for climate sensitivity of around 3.2°C.
其结果为气候科学提供一条珍贵的信息，也许是一条好小心。他的团队倾向于将气候敏感度标定为2.3°C，相比公认的数值降低了超过半度，其数值在66%的保证率下介于1.7° C至2.6°C间。更重要的是，气候敏感度的上限应该是3.2°C。

Before you take the SUV out for acelebratory spin, though, it is worth bearing in mind that this is only onestudy, and, like all such, it has its flaws. The computer model used is of only middlingsophistication, Dr Schmittner admits. That may be one reason for the narrowrange of his team's results. And although the study's geographical coverage isthe most comprehensive so far for work of this type, there are still blankareas-notably in Australia, Central Asia, South America and the northernPacific Ocean. Moreover, some sceptics complain about the way ancient data ofthis type were used to construct a different but related piece of climatescience: the so-called hockey-stick model, which suggests that temperatureshave risen suddenly since the beginning of the industrial revolution. It willbe interesting to see if such sceptics are willing to be equally scepticalabout ancient data when they support their point of view.
当你正为此而兴奋地冲入你的SUV来一次飚车，或者诸如此类的行为，稍等片刻，你的大脑应该想一想，这个理论固然有它的瑕疵。Schmittner博士承认，计算机模型的精度仅中等水平。这也许是其团队结果具有的一个局限性。另一个方面，尽管研究的区域覆盖范围在这一领域是最全面的，但仍然存在空白，特别是在澳大利亚，中亚，南美和北太平洋。另外，气候科学界一些对此持怀疑态度的人质疑，所使用的这些年代久远的数据，是一堆一个本质上不同但貌似有关联的片段，一个俗称为的曲棍球模型的现象。他们认为温度在工业革命初期，温度徒然升高。如果这些质疑者使用与怀疑那些年代久远的数据相同眼光审视他们支持的观点，这将会是一个非常有趣的现象。