气候变化对非洲水资源和农业的影响

A Review on Impacts of Climate Change on Water Resource and Agriculture in Africa

尽管非洲是世界上温室气体排放总量或人均排放量最少的地区,但在承受气候变化造成的恶劣影响方面首当其冲。气候变化已经给非洲的水资源、农业、生物多样性、人类健康和国家安全等带来诸多严重影响,粮食生产和水资源一直是非洲长期面临的两大难题,也是深受气候变化影响的两大领域。本文系统梳理了气候变化对非洲水资源系统和农业生产影响的研究成果和不足,以期为非洲气候变化影响评估工作提供一定参考和借鉴。已有的观测结果表明,气候变化导致非洲许多山脉冰川面积正在大范围缩减、大部分地区降水量有所减少,降雨的年际间分布也更为不稳定,通过水文模型的模拟预测,未来气候变化将进一步影响降水量和非洲部分地区河流的径流量,导致非洲水资源供给压力加大。同样,气候变化也给非洲农业生产带来了巨大的挑战,无论是观测结果分析,还是统计模型和作物模型等对不同气候情景和时间尺度下非洲农业的模拟研究,都显示气候变化对非洲农业以负面影响为主,导致非洲干旱加剧、生长季改变和粮食产量下降,并可能危及非洲的粮食安全。然而,现有研究结果还存在较多不确定性,其主要集中在未来气候情景数据、研究方法、数据的质量和数量等方面。与世界其它地区相比,非洲气候变化影响研究无论是研究的深度和广度都还较欠缺,需要在未来的研究中进一步加强,以探寻减缓气候变化对非洲水资源和农业不利影响的有效途径。

Africa shares the lowest portion of greenhouse gases emission in the world both in total and per capita,yet she suffers mostly from climate change.Climate change affects Africa＇s water resources,agriculture,biodiversity,human health,and national security.Food and water security are the two major challenges facing Africa whilst have been deteriorated by climate change.This study reviews the new findings of climate change impacts on water system and agriculture in Africa and their limitations,with the attempt to facilitate and promote enhanced researches related to climate change impact and vulnerability.Observation shows that climate change has led to rapid melting of glaciers,reduced rainfall and increased variability.Hydrological simulation demonstrates that further climate change would decrease precipitation and runoff in some areas,worsening current fragile water supply in most of Africa.Africa＇s agriculture faces unprecedented challenges under climate change.Both observation and simulation indicate climate change posed negative effects on Africa＇s agriculture.Increased risks of drought,changed growth season and decreased crop yield,would likely threat food security in Africa.Uncertainties in these studies mainly come from climate scenarios,methods,quality and quantity of data.Compared to other regions,Africa is short of comprehensive and in-depth researches related to climate change impact and vulnerability,therefore expects substantial investment on such activities to devise effective strategies in mitigating the negative effects of climate change on water resources and agriculture.