Soot climate forcing via snow and ice albedos
Soot climate forcing via snow and ice albedos
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DOI：
10.1073/pnas.2237157100
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发表时间：
2004-01-13
影响因子：
11.1
通讯作者：
Nazarenko, L
中科院分区：
文献类型：
--
作者：
Hansen, J;Nazarenko, L
对煤烟对冰雪覆盖率影响的合理估计（北极为1.5%，北方半球为3%）得出北方半球的气候强迫为+0.3 W/m（2）。这种强迫的“功效”近似于2，即，对于给定的强迫，它在改变全球地表空气温度方面的作用是CO2的两倍。这种间接的煤烟强迫可能导致了过去世纪的全球变暖，包括北方半球早春的趋势，北极海冰变薄，陆地冰和永久冻土融化。如果像我们所建议的那样，融化的冰和海平面上升定义了人类对气候系统的危险干扰水平，那么减少烟尘排放，从而将降雪量恢复到原始的高值，将具有减少全球变暖和提高危险人为干扰发生的全球温度水平的双重好处。然而，煤烟对气候变化的贡献并没有改变这样的结论，即人为温室气体是最近全球变暖的主要原因，并将成为未来主要的气候强迫。
Plausible estimates for the effect of soot on snow and ice albedos (1.5% in the Arctic and 3% in Northern Hemisphere land areas) yield a climate forcing of +0.3 W/m(2) in the Northern Hemisphere. The "efficacy" of this forcing is approximate to2, i.e., for a given forcing it is twice as effective as CO2 in altering global surface air temperature. This indirect soot forcing may have contributed to global warming of the past century, including the trend toward early springs in the Northern Hemisphere, thinning Arctic sea ice, and melting land ice and permafrost. If, as we suggest, melting ice and sea level rise define the level of dangerous anthropogenic interference with the climate system, then reducing soot emissions, thus restoring snow albedos to pristine high values, would have the double benefit of reducing global warming and raising the global temperature level at which dangerous anthropogenic interference occurs. However, soot contributions to climate change do not alter the conclusion that anthropogenic greenhouse gases have been the main cause of recent global warming and will be the predominant climate forcing in the future.