Mass Extinctions from Global Warming?

uncleO writes "The current issue of Scientific American has an interesting article, Impact from the Deep, about the possible causes for the five major global extinctions. It contends that only the most recent one was caused by a 'dinosaur killer' asteroid impact. Evidence suggests that the others were caused by 'great bubbles of toxic H2S gas erupting into the atmosphere' from the oceans due to anoxia." From the article: "The so-called thermal extinction at the end of the Paleocene began when atmospheric CO2 was just under 1,000 parts per million (ppm). At the end of the Triassic, CO2 was just above 1,000 ppm. Today with CO2 around 385 ppm...climbing at an annual rate of 2 ppm...to 3 ppm, levels could approach 900 ppm by the end of the next century."

Comments

The Cost of Fighting Global Warming

[schroedogg]

This idea that global warming is caused primarily by humans is speculative at best. In the past 120 years, the average surface temperature has only risen 1.2 degrees F in North America. Because measuring has not been as accurate as it is now, this may not be a totally accurate number. Plus, most of this can be attributed to things not caused by human action such as retreated glaciers, volcanos, etc. Do we really know for sure that WE are causing global warming?

Also, think of all the negatives of fighting this perceivedly harmful warming. One, the poor will become poorer because they won't be able to afford the latest fuel efficient cars, furnaces, etc. We just recently purchased a "new" (used) car and found that it was manufactured to meet california emissions standards, though we do not live in California nor was it manufactured there. Because of this, a simple $50 oxygen sensor that needs replacing is now going to cost $150. On top of that, it has not 1 but 2 catalytic converters, which are another expensive part to replace. Then think about the benefits of global warming. Warmer weather means a longer growing season, which could be a boon to agritculture in 3rd world countries. Also, more people die from cold each year than from heat, so a warmer planet could mean less deaths due to temperature.

Of course, these are assuming the warming doesn't eventually result in some sort of catastrophe, but I think the evidence for this is very shaky at best. Don't believe everything the media is spitting out currently. I think this whole catastrophe theory is a very politically motivated issue with a little bit of science behind it.