期刊文献+
共找到1篇文章
< 1 >
每页显示 20 50 100
Sun, climate, hunger, and mass migration 被引量:13
1
作者 kennethj.hsu 《Science China Earth Sciences》 SCIE EI CAS 1998年第5期449-472,共24页
Paleoclimatic studies indicate four epochs of global cooling during the last 4 000 years, i.e. during the few centuries before and after 2000 BC, 800 BC, 400 AD, and 1 600 AD; the quasiperiodicity corresponds to cycli... Paleoclimatic studies indicate four epochs of global cooling during the last 4 000 years, i.e. during the few centuries before and after 2000 BC, 800 BC, 400 AD, and 1 600 AD; the quasiperiodicity corresponds to cyclic variation of solar activity. Global temperature changes influenced regional precipitation patterns: Northern Europe was wetter while the middle and low latitude lands were more arid during colder epochs. Both sets of cold climatical conditions were unfavorable for agricultural production. Historical records show that large demographic movements in history took place because of crop failures and mass starvation, rather than escaping from war zones. The "wandering" of the Germanic tribes during the first two or three centuries of the Christian Era is one example. Whereas the accelerated release of carbon dioxide from the burning of fossil fuels is ultimately to cause global warming, historical evidence indicates, however, that global warming has been on the whole a blessing to mankind. Global cooling, on the other hand, has curtailed agricultural production and has led to famines and mass migrations of people. Perhaps the most important task at the present is not so much computer modelling of greenhouse effect on global climate, but water management and agricultural researches to insure food supply for an everincreasing world population. 展开更多
关键词 SUN CLIMATE HUNGER MASS migration.
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部