厄尔尼诺与全球趋暖灾害骤增对农业持续发展的影响

EI Nino, Global Warming and Disasters Increasing: Impacts on Sustainable Agricultural Productivity

根据近 1 2 0年来全球大气温度的记录 ,进行了每 1 0年平均气温的分析 ,可以明显地划分为 3个时期即温度偏低期 (1 880～ 1 91 9年 ,至少 40年 ) ,过渡期 (温度变化起伏不大 ,1 92 0～ 1 979年 ,约 60年 )和升温期。再参照有关小冰期 (1 4 50或 1 4 90年开始至 1 850或 1 880年止 ,约 40 0年 )的文献资料 ,小冰期的气温比 1 880～ 1 91 9年时期更低些 ,因此推论温度偏低期持续了约 450年。由此可见 ,近 450年全球大气温度的变化 ,大体上是一个单向渐变过程。根据本世纪厄尔尼诺出现的情况 ,也可划分为三个明显不同的时期 :从1 90 0年有记录开始至 1 940年为厄尔尼诺偶见期 ,在此时期尚未看出全球变暖 ;1 940～1 980年为厄尔尼诺中等发生期 ,全球出现微弱或中等程度的升温 ;1 980～ 1 998年为厄尔尼诺频繁出现期 ,此时全球明显升温。由此认为 1 0 0年来厄尔尼诺的出现情况 ,类似上述全球大气升温的单向渐变过程。本文考虑到海洋的热惯性 ,提出应关注温室效应和厄尔尼诺的叠加效应的新观点 ,提出今后几十年或更长时间内 ,厄尔尼诺仍将频繁出现 ,全球温度将保持偏暖状态。与此伴同发生的是各类自然灾害如洪涝、干旱、生物灾害等的频繁出现并加剧。应做好防灾减灾工作 ,维护农业持续生产力。

Three periods are clearly divided based on decadal mean temperatures of the records for global surface temperatures of recent 120 years. The first of them was the period of lower temperature (from 1880 to 1919, at least 40 years), the second was the period of transition(fluctuation of temperature was not too much, from 1920 to 1979, about 60 years), the third is the period of temperature increasing. We understand the temperature of the Little Ice Age was lower than that of the period from 1880 to 1919 according to the references of the Little Ice Age (from 1450 or 1490 to 1850 or 1880, about 400 years). Therefore imagined duration of lower temperature is about 450 years. The variations of temperature for the recent 450 years are the kind of the process of unidirectional, gradual change. Another three periods may be also divided according to the situation of EI Nino emerging in this century. The first period was that of EI Nino accidental emerging from 1900 to 1940. The second period was that of EI Nino middle emerging from 1940 to 1980, the global temperature was increasing at faint or middle level for this period. The third period is that of frequently emerging of EI Nino from 1980 to 1998, the global warming is obviously. Recent 100 years the situation of EI Nino emerging is similar with the process of unidirectional, gradual change for global temperature. The new viewpoint, that is to pay close attention to the influences on the piled effects of greenhouse effect and EI Nino, is given out after thinking the thermal inertia of ocean. We think the EI Nino will be frequently emerged and global temperature will be also kept the warmer state for several decades or longer period in the future. The natural disasters, such as flood, drought, bio calamities etc., will be frequently took place following EI Nino and global warming. Therefore we should do the works for taking precautions against and reducing natural calamities, and safeguard the sustainable agriculture productivity.