Megafauna Extinction Due to Climate

jvchamary writes "Most biologists believe that Earth is currently undergoing its sixth mass extinction. The cause? Human activity, either directly (e.g. the Dodo) or indirectly (e.g. the Amazon rainforests). The disappearance 30,000-45,000 years ago of the Australian megafauna, large animals such as the marsupial lion, is often attributed to hunting by Aboriginal settlers. However, recent research in Proceedings of the National Academy of Sciences suggests that it was more likely a shift in climate, rather than hunting, that caused the over-sized organisms to die-out (via Nature and the BBC)."

Comments

Solar Activity Coinciding with Climate Change

[bacon55]

There's a lot of evidence to link large scale climate change with periods of heightend and lowered activity in the Sun.

Taken From "http://www.exploratorium.edu/sunspots/"

From 1645 to 1715, there was a drastically reduced number of sunspots. This period of reduced solar activity, which was first noticed by G. Sporer and was later investigated by E.W. Maunder, is now called the Maunder Minimum. This period of time was also unusually cold on earth, and it has been referred to as the "Little Ice Age." This has led to some speculation that sunspot activity may affect the earth's climate. Similar periods of low solar activity seem to have occurred during the Spoerer Minimum (1420-1530), the Wolf Minimum (1280-1340), and the Oort minimum (1010-1050). Solar astronomers label solar cycles from one minimum to the next, and assign them numbers, starting at one, with the 1755-1766 cycle.

Personally, I've always found it rather arrogant to believe we are the greatest cause of climate change on Earth. Lol, it could be that the Sun is literally causing us to use more energy...but thats taking the butterfly effect a little too literally - maybe.

Re:Bummer...

[Rei]

I forgot to mention another reason why climate clearly isn't the only issue: Holdouts. For several species, there were inaccessable regions which humans didn't discover right away - for example, mammoths on Wrangel Island. While the climate changed around them, they survived just fine. Their mainland bretheren, encountering humans and their side effects, died out.

Re:MegaBeaver

[Neop2Lemus]

The above, you ignant prudes is not flamebait.

ackthpt, however that is pronounced :-p, I'm not sure the beaver was 6' tall, here's a picture of a model one courtesy of the CBC: Castoroides ohioensis. That's the host of the show, Quirks & Quarks beside him.