2012-05-28 08:46:09| 分类： 环境科学 | 标签：胡德良 地球变暖 大气污染物 太阳活动 温室气体
跟1960年以后的观测数据最为匹配的气候模拟结果表明：2050年全球平均温度要比1961年到1990年期间测得的全球平均温度高出1.4°C至3°C。
Earth Warming Faster Than Expected
by Sid Perkins 胡德良 译
| By 2050, global average temperature could be between 1.4°C and 3°C warmer than it was just a couple of decades ago, according to a new study that seeks to address the largest sources of uncertainty in current climate models. That's substantially higher than estimates produced by other climate analyses, suggesting that Earth's climate could warm much more quickly than previously thought. | 一项新研究表明：到2050年，全球平均温度可能会比刚刚过去的几十年前高出1.4°C至3°C。这项新研究的目的是要解决当前气候模拟中存在的最大的不确定因素。这个上升幅度比其他气候分析得出的估计数据要高得多，因而说明地球气候的变暖速度可能比以前所预料的要快得多。 |
| Many factors affect global and regional climate, including planet-warming "greenhouse" gases, solar activity, light-scattering atmospheric pollutants, and heat transfer among the land, sea, and air, to name just a few. There are so many influences to consider that it makes determining the effect of any one factor—despite years and sometimes decades of measurements—difficult. | 许多因素会影响到全球和区域的气候，其中包括使地球变暖的温室气体、太阳活动、具有光散射作用的大气污染物以及大地、海洋和空气之间的热传导（这里只是列举了少数几个因素）。尽管有几年甚至几十年的测量数据，但是由于有很多因素需要考虑，因此要想确定任何一种因素的影响有多大仍然是很困难的。 |
| Daniel Rowlands, a climate scientist at the University of Oxford in the United Kingdom, and his colleagues took a stab at addressing the largest sources of short-term climate uncertainty by modifying a version of one climate model used by the United Kingdom's meteorological agency. In their study, the researchers tweaked the parameters that influence three factors in the model: the sensitivity of climate to changes in the concentration of carbon dioxide in the atmosphere, the rate at which oceans absorb heat from the atmosphere, and the amount of cooling from light-scattering aerosols in the atmosphere. | 英国牛津大学的气候科学家丹尼尔·罗兰兹及同事企图通过更改英国气象局使用的一种气候模型，找出造成短期气候变化的最主要因素。在研究中，研究人员稍微调整了在模拟中影响三个因素的参数，这三个因素为：气候对于大气中二氧化碳浓度变化的敏感度、海洋从大气中吸收热量的速度以及大气中具有光散射作用的气溶胶所造成的冷却幅度。 |
| Then the team analyzed the results of thousands of climate simulations—each of which had a slightly different combination of parameters—that covered the years between 1920 and 2080, Rowlands says. All of the simulations assumed that future concentrations of greenhouse gases would rise from today's 392 parts per million to 520 ppm by 2050. Each of the runs also allowed for variations in solar activity (which would affect how much the sun's radiation warms Earth) and rates of volcanic activity (which would influence the concentrations of planet-cooling sulfate aerosols in the atmosphere). | 罗兰兹称，研究小组随后分析了几千次气候模拟的结果，每次模拟都利用稍微不同的参数组合，而且模拟包括了1920年至2080年期间的情况。所有的模拟都假定未来的温室气体浓度会从当今的392ppm上升到2050年的520ppm。每次运算都考虑到了太阳活动的变化和火山活动的等级。太阳活动会影响使地球升温的太阳辐射量；火山活动等级会影响大气中硫酸盐气溶胶的浓度，而气溶胶具有为地球降温的作用。 |
| The team discarded results of simulations that didn't match observations of regional climate in more than 20 land areas and ocean basins from 1960 to today. Of those that passed this test, those considered statistically most likely—the two-thirds of those that best matched previous climate observations—suggest that global average temperature in 2050 will be between 1.4°C and 3°C warmer than the global average measured between 1961 and 1990. All of the simulations that matched recent climate patterns suggested warming would be at least 1°C, the researchers report online today in Nature Geoscience. | 研究小组丢弃了一些模拟结果，因为这些结果与20多个陆地和洋盆在1960年到目前期间的区域气候观测数据不一致。在那些通过匹配测试、被认为在统计上具有极大可能性的模拟中，有三分之二跟以前的气候观测数据非常一致。模拟表明：到2050年全球平均气温将比1961年至1990年期间所测得的全球平均气温高出1.4°C至3°C。今天，研究人员在《自然-地球科学》杂志在线版上报道说：所有与近期气候模式一致的模拟表明变暖幅度将至少为1°C。 |
| The higher end of the team's range of likely warming scenarios is between 0.5°C and 0.75°C warmer than the scenarios published in the last report of the Intergovernmental Panel on Climate Change, Rowlands says. "These sorts of numbers haven't been seen in other complex climate models." | 罗兰兹说，跟政府间气候变化专门委员会上一次发布的报告情况相比，研究小组得出的最高变暖幅度可能会高出0.5°C至0.75°C。他说：“这种数据在其他复杂的气候模拟中是没有见到过的。” |
| "I think people will be very interested in taking a close look" at details of the simulations that yielded unusually high estimates of warming to ensure the results are credible, says Isaac Held, a climate scientist with the National Oceanic and Atmospheric Administration in Princeton, New Jersey. Nevertheless, he notes, the team's set of simulations is a valuable resource for further analysis of climate change. Eventually, he suggests in a commentary in Nature Geoscience, results of the new study may help scientists not only quantify the uncertainty in climate analyses but also reduce it. | 新泽西州普林斯顿市国家海洋和大气管理局的气候科学家艾萨克·赫尔德说：“这些模拟在变暖幅度方面产生了特别高的估计数据，因而我认为，人们想确切了解模拟结果的可信性，他们将会对于仔细查看模拟的详细情况非常感兴趣。”然而，他指出：对于进一步分析气候变化来说，研究小组的这套模拟是一种有价值的资源。最后，赫尔德在《自然-地球科学》的一篇评论中提出：这项新研究的成果不仅可以帮助科学家们量化气候分析中的不确定因素，而且还有助于减少这些不确定因素。 |
译自：美国《科学》杂志网站（25 March 2012, 1:05 PM）
原著：Sid Perkins
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