Firestone et al., 2007, PNAS 104(41): 16,016–16,021, proposed that a major cosmic impact, circa 10,835 cal. BCE, triggered the Younger Dryas (YD) climate shift along with changes in human cultures and megafaunal extinctions. Fourteen years after this initial work the overwhelming consensus of research undertaken by many independent groups, reviewed here, suggests their claims of a major cosmic impact at this time should be accepted. Evidence is mainly in the form of geochemical signals at what is known as the YD boundary found across at least four continents, especially North America and Greenland, such as excess platinum, quench-melted materials, and nanodiamonds. Their other claims are not yet confirmed, but the scale of the event, including extensive wildfires, and its very close timing with the onset of dramatic YD cooling suggest they are plausible and should be researched further. Notably, arguments by a small cohort of researchers against their claims of a major impact are, in general, poorly constructed, and under close scrutiny most of their evidence can actually be interpreted as supporting the impact hypothesis.

Firestone等人，2007，PNAS 104（41）：16016-16021，提出了主要的宇宙影响，约为10835卡。公元前（BCE），随着人类文化的变化和巨型动物的灭绝，引发了年轻的树蛙（YD）气候变化。这项初步工作开展十四年后，这里回顾了许多独立团体进行的研究的压倒性共识，这表明他们应接受此时宣称对宇宙产生重大影响的主张。证据主要是在至少四个大洲，尤其是北美和格陵兰岛上发现的所谓的YD边界的地球化学信号，例如过量的铂，淬火熔融的材料和纳米金刚石。他们的其他说法尚未得到证实，但是事件的规模，包括大范围的野火，而且，随着YD急剧冷却的开始，时间非常接近，这表明它们是合理的，应进一步研究。值得注意的是，一小群研究人员反对其对重大影响的主张的论点总体上讲构造较差，并且经过严格审查，他们的大多数证据实际上可以解释为支持影响假说。