Tipping Points in the Tundra
Tipping Points in the Tundra
复制标题
苔原的临界点
DOI：
10.1126/science.1120104
复制
发表时间：
2005
期刊：
影响因子：
56.9
通讯作者：
P. Braconnot
中科院分区：
文献类型：
--
作者：
J. Wohlfahrt;S. Harrison;P. Braconnot
北极的环境变化可能是全球气候变化的早期预警系统，该地区最近的报告令人震惊。几项研究表明，海冰覆盖面积大幅减少，海冰提前融化，导致海冰达到世纪以来的最低水平。现在有证据表明，附近大陆的变暖也可能正在加速。在他的观点中，[Foley][1]讨论了[ Chapin et al. ][2]在同一问题上报告的结果，这些结果表明，最近北极变暖引起的高反射性积雪减少以及灌木和树木覆盖的扩大正在放大该地区的温度变化。减少的积雪和扩大的灌木和树木都可以吸收额外的太阳辐射（与高反射率的雪地相比），使地表和大气变暖。Chapin等人为这种气候反馈机制提供了迄今为止最好的经验证据;这些结果需要更充分地纳入未来气候变化的模型中。
[1]：http://www.sciencemag.org/cgi/content/full/310/5748/627
[2]：http://www.sciencemag.org/cgi/content/short/310/5748/657
Environmental changes in the Arctic may be an early warning system for global climate change, and recent reports from the region are alarming. Several studies have indicated substantial declines in sea ice cover and earlier ice melting, which have led to the lowest level of sea ice in more than a century. And now there is evidence that the warming on the nearby continents may also be accelerating. In his Perspective, [Foley][1] discusses results reported in the same issue by [ Chapin et al. ][2] that suggest that reductions in highly reflective snow cover and expanding shrub and tree cover, both caused by recent warming in the Arctic, are amplifying the temperature changes in the region. Reduced snow cover and expanded shrubs and tress both act to absorb additional solar radiation (compared to highly reflective snow fields), warming the surface and the atmosphere above. Chapin et al. provide the best empirical evidence for this climate feedback mechanism to date; these results need to be more fully incorporated into models of future climate change.
[1]: http://www.sciencemag.org/cgi/content/full/310/5748/627
[2]: http://www.sciencemag.org/cgi/content/short/310/5748/657