经济学人下载:气候变化影响农作物产量

Climate change and crops
气候变化与农作物

Hindering harvests
妨害产量

Changes in the climate are already having an effect on crop yields—but not yet a very big one
气候变化已经对农作物产量造成影响——但是迄今影响不大

May 5th 2011 | from the print edition

THE problems climate change looks likely to bring in the future may increasingly be visible in the records of the past. Not just in the far-off ages of surging sea levels following ice-age thaws, spikes in prehistoric temperatures correlated with natural releases of greenhouse gas and ancient civilisations brought low by drought, but in records from living memory—which are based on reliable measurements made at the time. Using such data researchers have now compiled an estimate of global changes in crop yields which can be put down to recent increases in temperature and decreases in rainfall (the world as a whole is getting wetter, but the rain has stayed away from some agricultural plains). The bad news is that they find that climate change has lowered the amount of maize (or corn, if you prefer) and wheat produced in a given area. The good news is that the effect is so far reasonably small.

冰河融化后的远古时代，海平面急剧上升，由于温室气体的自然释放，气温处于史前时代最高峰，古代文明由于干旱而衰落。在记忆可及的近代，人们根据可靠的测量对气候变化做了记录。根据过去的这些记录，气候变化可能造成的影响，在未来也许会越来越明显。研究人员利用这些数据，现在已经对全球农作物产量的变化做出了估计。农作物产量变化的原因可能是近来气温的升高和降水的减少（世界总的来说越来越潮湿，但是雨水远离了好些农业平原地区）。消息有好有坏。坏消息是，他们发现，在上述地区气候变化使玉米（或叫包谷，如果您喜欢的话）和小麦减产。好消息是，迄今为止气候变化的影响相当小。