摘要

编者按:气候对自然生态系统和人类社会的影响

作者(年代):纳斯林Salehnia

全球变暖及其相关的水文循环变化和海平面上升预计将对自然生态系统、人类健康和经济造成严重的负面影响。据预测，气候变化将破坏生态系统，并导致物种多样性的丧失，因为许多物种将无法适应快速变化的环境条件。一些生态系统，如热带山地、红树林和北极生态系统，可能会消失，因为气候变暖或海平面上升将无法支撑它们。在高纬度地区，变暖将导致永久冻土退化和湿地甲烷释放增加。因为甲烷是二氧化碳之后的下一个重要温室气体，这也会加剧全球变暖。耦合气候模式模拟表明，21世纪欧洲和美国大部分地区夏季土壤湿度将显著下降。这可能对自然植被和农业产生潜在的严重负面影响，并导致森林火灾频率增加。气候变暖和水循环变化将对许多地区的水资源造成严重影响。目前，全球三分之一的人口生活在缺水的国家。未经缓解的全球变暖将大大增加面临水资源压力的人数。 At the same time, increased probability of extreme weather events, such as catastrophic floods, heat waves, and more devastating hurricanes, are expected to increase the death rate associated with natural disasters. Sea-level rise will have a profound negative socio-economic impact by increasing the risk of coastal flooding and causing the loss in coastal wetlands. In particular, the estimates show that unmitigated global warming could increase annual number of people in coastal storm surges by factor 10 already in the year 2080. Another potential health impact of global warming is related to the increase of the area where climate is suitable to malaria transmission. Currently, distribution of malaria is limited to the Tropics but global warming could considerably extend this area, which will lead to an increase in the number of people exposed to malaria. Among recently recognized aspects of rising of atmospheric CO2 concentration is the acidification of the ocean. The observation and modeling results indicate that carbon dioxide emission from human activity has already led to a reduction of the averaged pH of surface seawater of 0.1 units and pH will fall additionally by 0.5 units by the year 2100. This could lead to mass extinction of coral and some plankton species causing disruption of the entire marine food chain.