一个国际研究小组在最新出版的美国《国家科学院学报》上报告说,温室气体可导致海平面在未来数个世纪持续上升,全球平均气温每升高1摄氏度,海平面可能上升超过2米。
德国波茨坦气候影响研究所等机构的研究人员基于早期气候数据和计算机模型得出结论,在20世纪,海平面上升大约0.2米,预计到本世纪末将上升不到两米。不过,海平面的相对“缓慢”上升背后潜藏巨大风险,其后全球平均气温每升高1摄氏度,海平面上升可能超过2米。
研究显示,现阶段,海水热膨胀和高山冰川融化是海平面变化的主要因素,但随着时间推移,格陵兰岛冰原以及南极冰盖融化将成为未来海平面上升的主要“贡献者”。
研究人员认为,目前地球海平面还没有明显升高,这主要是由于冰原的面积和体积太大,融化速度缓慢。而一旦持续升高的气温打破了目前的这种相对平衡,冰原融化速度就会加快,海平面的上升也将会加速。
波茨坦气候影响研究所的安德斯·莱韦尔曼说,人们应及早采取应对海平面上升的措施。(生物谷Bioon.com)
生物谷推荐的英文摘要
PNAS doi:10.1073/pnas.1309353110
Improved El Niño forecasting by cooperativity detection
Josef Ludescher, Avi Gozolchiani, Mikhail I. Bogachev, Armin Bunde, Shlomo Havlin, and Hans Joachim Schellnhuberd
Although anomalous episodic warming of the eastern equatorial Pacific, dubbed El Niño by Peruvian fishermen, has major (and occasionally devastating) impacts around the globe, robust forecasting is still limited to about 6 mo ahead. A significant extension of the prewarning time would be instrumental for avoiding some of the worst damages such as harvest failures in developing countries. Here we introduce a unique avenue toward El Niño prediction based on network methods, inspecting emerging teleconnections. Our approach starts from the evidence that a large-scale cooperative mode—linking the El Niño basin (equatorial Pacific corridor) and the rest of the ocean—builds up in the calendar year before the warming event. On this basis, we can develop an efficient 12-mo forecasting scheme, i.e., achieve some doubling of the early-warning period. Our method is based on high-quality observational data available since 1950 and yields hit rates above 0.5, whereas false-alarm rates are below 0.1.