欧洲人殖民美洲引致地球变冷？

西方不严谨的科研

李兆良

2019.2.2 

西方有名的学刊不一定发表严谨的论文，不能迷信西方的科研一定正确。

下面是一个最近的例子。 这篇的作者是伦敦大学与里斯大学地理学系的学者写的，发表在Quaternary Science Reviews。文章认为“哥伦布引起欧洲殖民美洲，杀害了百分之九十的原住民，减低大气的二氧化碳，引起地球降温”。这篇文章只从一方面来考虑地球降温，而没有考虑别的因素，造成极大的误导。必须声明，欧洲人殖民美洲，屠杀了90% 以上的原住民是不可宽恕的罪行，但是，把地球进入小冰河时期归咎于原住民人口大量减少是偏颇的。

科研是严肃的事情，不能带有政治立场，有意或无意用片面的、有选择性的数据来解释既定的结论，必须是全面考虑问题，多方考证，得出无可辩驳的结论，才是真正科研的态度。

因为引用英文原文和分析方便起见，下面我用英文阐述我的观点。

A controversial paper entitle “Earth system impacts of the European arrival and Great Dying in the Americas after 1492” is recently published in Quaternary Science Reviews, 207:13-36, 2018. (December 2018) https://doi.org/10.1016/j.quascirev.2018.12.004                                                

这篇文章的数据表面很严谨，事实上是无视其他重要的因素，造成误导。以下是我的评论：

This has raised some controversy because of the conclusion is based on a very limited area while overlooking other factors.  

I think some significant factors should be reviewed:

1.      The Black Death (1347-1351) is estimated to have killed 30–60% of Europe’s total population. In total, the plague may have reduced the world population from an estimated 450 million down to 350–375 million in the 14^th century, viz. ~100 million European people were wiped out. This is about the same as or more than the population of Native America. There was indeed a subsequent minor Ice Age, but the effect should be noticeable immediately.

2.      Carbon dioxide is most absorbed by huge trees rather than herbal crops.

3.      Between 1500 and 1600, the colonization was limited to eastern and coastal Americas. The vast forests in Midwest were untouched.

4.      Volcano eruption would be a far more destructive natural force to cause a minor ice age. There is no lack of such events during late 1500- early1600 CE. Nevado del Ruiz in Columbia (1595), Huaynaputina in southern Peru (1600), Billy Mitchell of Papua New Guinea (~1580) are some more prominent examples. Rather than the depletion of carbon dioxide, it could be the emission of gases shielding the sun that caused a cooling of the Earth. Plenty of examples can be cited about volcanic eruption as the cause for drastic cooling of earth and massive extinction of animals, including dinosaurs.

The massive killing of Native Americans should not be condoned, but the association with a decline in atmospheric carbon dioxide and a subsequent cooling of the earth is overlooking other more important factors.  

李兆良

2019.2.2