炭黑的气候威胁“被低估”
Black carbon climate danger 'underestimated'
科学家发现，烟灰的关键成分炭黑在全球变暖中发挥的作用比过去所认为的更大。他们认为，炭黑是仅次于二氧化碳的全球变暖第二大促进因素。
Black carbon, a key component of soot, plays a much larger role in global warming than previously estimated, scientists have found.They cite black carbon as the second largest contributor to global warming after carbon dioxide.
美国加州大学圣地亚哥分校Scripps海洋学研究所教授Veerabhadran Ramanathan是这项研究的共同作者。他说：“我们现在又要担心另一样东西了。我们过去认为主要是二氧化碳[导致全球变暖]。现在我们知道，还有另外一个主要的罪魁祸首。我们的研究让这个问题更加复杂了。”
"We've got one more thing to worry about," says Veerabhadran Ramanathan, professor at the Scripps Institution of Oceanography at the US-based University of California at San Diego and co-author of the study."We thought it was mainly carbon dioxide emissions [contributing to global warming]. Now we know that there is another major culprit. Our finding adds to the complexity of the issue."
炭黑是由木头、诸如作物残余等生物质以及化石燃料不充分燃烧产生的。
Black carbon is produced from the incomplete combustion of wood, biomass such as crop residues and fossil fuels.
Ramanathan与其共同作者、美国爱荷华大学的Greg Carmichael把卫星数据与飞机航测和地面观测数据结合起来，描绘了这幅炭黑排放导致变暖效应的全球图景。
Ramanathan, together with Greg Carmichael at the University of Iowa, United States, combined satellite data with aircraft and surface observations to paint a global picture of the warming effects of black carbon emissions.
炭黑吸收阳光辐射，让大气增温。作者们估算，这种致暖效应达到了每平方米0.9瓦，仅次于二氧化碳的每平方米1.66瓦的效应。但是，这比联合国政府间气候变化专门委员会（IPCC）估计的每平方米0.2—0.4瓦的致暖效应高得多。
Black carbon absorbs solar radiation, warming the atmosphere. The researchers calculated this warming effect as 0.9 watts per square metre, second to carbon dioxide's value of 1.66 per square metre.But this is much higher than the 0.2–0.4 watts per square metre estimated by the UN Intergovernmental Panel on Climate Change.
Ramanathan对本网络记者表示，减少炭黑排放有现实可能性，因为它在大气层中的生命周期很短，“只有10天左右。”结果，减排的效应立竿见影。
Ramanathan told SciDev.Net that reducing black carbon emissions is a real possibility as the atmospheric lifespan of black carbon is short, "in the order of ten days or less". As a result, the benefits will be reaped quickly.
他说，“为了减排二氧化碳，我们谈的都是上万亿美元的事情，而我的感觉是减排碳黑的开销要便宜10倍到100倍。在过去30—40年间，美国和英国的炭黑排放减少到了原来的1/2到1/3。这表明我们知道该如何做。”
"To cut down carbon dioxideemissions, we are talking about trillions of dollars," he says. "My feeling is black carbon is going to be 10–100 times cheaper. Black carbon emissions in Germany and the United Kingdom have come down by a factor of 2–3 in the last 30–40 years. This shows that we know how to do it."
Ramanathan正在印度进行一项研究，审视沼气工厂的性价比并鼓励在村庄中利用太阳能炊具而不是燃烧生物质。他正在与芝加哥气候交易委员会合作为这些村民们提供碳信用额来维持这些新的炊事方法。
Ramanathan is undertaking a study in India to look at the cost-effectiveness of biogas plants and encouraging the use of solar cookers instead of burning biomass in villages.He is currently working with the Chicago Climate Exchange Commission to provide the villagers with carbon credits to sustain these new cooking methods.
联合国今年晚些时候将发布报告，根据Ramanathan和Carmichael的分析，来评估大气褐色云对中国和印度的影响。大气褐色云是由炭黑与其它气溶胶结合生成的。
A report building on Ramanathan's and Carmichael's analysis, assessing the impact of atmospheric brown clouds ― formed from the mixing of black carbon with other aerosols ― on China and India will be released by the UN later this year.
Ramanathan和Carmichael的研究发表于《自然·地球科学》上。
The study was published in Nature Geoscience.
本文由科学与发展网络(SciDev.Net)独家提供。
