Global Warming May Have Killed the Dinosaurs

The Fun Guy sent in a link to the American Society for Microbiology site, your leading news source for everything between nano and macro. The site is featuring a story about new research into the KT barrier extinction: the period in history where the dinosaurs went extinct, along with a number of other families of species. For a number of years scientists have theorized that an impact on the Yucatan peninsula was responsible for the species crash, but microbiological examination of marine organisms of the time indicate life persisted for another 300,000 years after the 'Chicxulub impact'. The researchers at Princeton who made this discovery theorize that global warming caused by a volcanic eruption in India is a more likely culprit for the world-wide devastation. The article generalizes that there is no 'smoking gun' for this event, and further research is required.

Comments

What I have always wondered about...

[starseeker]

The Chicxulub event, while large, is not the only large impact suffered in Earth's history. There are quite a number of large craters in the geologic history, and probably more that we have not stumbled upon yet. The Earth Impact Database lists two craters larger than Chicxulub:

http://www.unb.ca/passc/ImpactDatabase/CIDiameterS ort2.htm

Wikipedia blurbs on the two largest (as usual, do more research to verify if interested:)

http://en.wikipedia.org/wiki/Vredefort_crater
http://en.wikipedia.org/wiki/Sudbury_Basin

There are also questions about a possible crater in Antarctica, but it's too new an announcement to know if the features observed are actually impact related: http://researchnews.osu.edu/archive/erthboom.htm

My question is, why would the Chicxulub event have been so uniquely deadly?

I suppose one possible scenario is a double (or more) sucker punch of large impact followed by volcanic activity and/or other factors that happened to hit while the Earth was still recovering from the impact. Of course, that's a bit complex for a spectacular headline.

I hope work continues on this - it's a fascinating insight into our environment and might be useful in knowing how to safeguard ourselves against changes in the future.

Re:Well, THERE'S the problem!

[syphax]

General rant (sorry iminplaya, you're the straw and I'm the camel):

Every time a global warming story comes up, lots of readers throw out their own unsubstantiated (or more usually debunked) theories, without bothering with basic fact checking. Here, the parent is 'certainly interested' in geologic CO2 fluxes, but can't be bothered to search. Are geological CO2 fluxes being measured? Yes. It's called Wikipedia, people.

Sorry. But if someone throws out solar fluctuations as the primary reason for current warming one more time, I'm going to be very, very cross. Do some research.

Start here
Carbon flux- humans have thrown the net flux out of whack
The ocean is a carbon sink, thanks to us
Here's the carbon cycle. Lots of big fluxes, but we've tipped the balance