Did a Comet Hit Earth 12,000 Years Ago? (causing the "Younger Dryas")

[OKIsItJustMe]

http://www.sciam.com/article.cfm?id=did-a-comet-hit-earth-12900-years-ago

News - January 2, 2009

Did a Comet Hit Earth 12,000 Years Ago?

Nanodiamonds found across North America suggest that major climate change could have been cosmically instigated

By David Biello
Roughly 12,900 years ago, massive global cooling kicked in abruptly, along with the end of the line for some 35 different mammal species, including the mammoth, as well as the so-called Clovis culture of prehistoric North Americans. Various theories have been proposed for the die-off, ranging from abrupt climate change to overhunting once humans were let loose on the wilds of North America. But now nanodiamonds found in the sediments from this time period point to an alternative: a massive explosion or explosions by a fragmentary comet, similar to but even larger than the Tunguska event of 1908 in Siberia.

Sediments from six sites across North America—Murray Springs, Ariz.; Bull Creek, Okla.; Gainey, Mich.; Topper, S.C.; Lake Hind, Manitoba; and Chobot, Alberta—yielded such teensy diamonds, which only occur in sediment exposed to extreme temperatures and pressures, such as those from an explosion or impact, according to new research published today in Science.

The discovery lends support to a theory first advanced last year in that some type of cosmic impact or impacts—a fragmented comet bursting in the atmosphere or raining down on the oceans—set off the more than 1,300-year cooling period in the Northern Hemisphere known as the Younger Dryas for the abundance of an alpine flower's pollen found during the interval.

The cooling period interrupted an extended warming out of an ice age predicted by slight changes in Earth's orbit (known as Milankovitch cycles) that continues today. And it remains an unexplained anomaly in the climate record.

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[Bigmack]

1. Interesting...

Even the less than liberal Union Tribune of San Diego carried this article this AM. But I suppose the notion that climate change is caused by "stuff" beyond human control WOULD appeal to conservatives. But still, this "theory" is sure interesting and it'll be interesting to see what, if any, further evidence will be turned up in support of it. Ms Bigmack

[Citizen Number 9]

2. I think I see where this is going, so help me to understand...

The GW deniers go for this all the time and I just can't get why this logic is so popular.


If Global Warming can be caused by things other than man made greenhouse gases, how does that prove we aren't responsible for Global Warming right now?