What wiped out half the marine life on Earth two hundred million years ago?
Conventional wisdom says it was major volcanic activity, but maybe not, New research just published in the journal Science says a more likely cause was the release of a huge amount of methane into the atmosphere from the sea floor. The researchers note that the volcanoes were active for 600,000 years, but the marine extinction only took 10,000 to 20,000 years. By studying the carbon isotopes of sediment from the extinction period, the scientists found that the marine extinction coincided with the methane release. What caused the methane to be released? Volcanic eruptions emitted carbon dioxide (CO2), warming both global atmospheric and oceanic temperatures. The oceans got warm enough to release the methane from the sea floor.
The study could foreshadow the effect of climate change on Earth. The build–up of CO2 in the atmosphere, not from volcanoes but from fossil fuel use, could warm the planet enough to release methane from the ocean floors. GR
