CO2 from large igneous provinces linked to extinction events

Human activity is currently causing large increases in CO2, and nature does not distinguish between CO2 from human activity and that from natural sources.

http://www.eurekalert.org/pub_releases/2015-10/gsoa-lip103015.php

Public Release: 30-Oct-2015
Large igneous provinces linked to extinction events
Geological Society of America

Mass extinction events are sometimes portrayed in illustrations of volcanic eruptions causing widespread destruction. According to Dr. Richard E. Ernst of Carleton University, Ottawa, Canada, expert on Large Igneous Provinces (LIPs), this interpretation may have some truth behind it, but not in the instantaneous way we might think. Ernst will report on his research on 1 November at the Geological Society of America's Annual Meeting in Baltimore, Maryland, USA.

The basaltic lava flowing from ancient volcanoes and the portion of magma (liquid rock) emplaced underground can create geologic conditions linked with climate change and, subsequently, extinction events. This climatic effect is particularly true for LIPs, in which mainly basaltic magma up to millions of cubic kilometers can be emplaced in a geologically short time of less than a few million years.

"The most dramatic climatic effect is global warming due to greenhouse-gases from LIPs," explains Ernst. "Subsequent cooling (and even global glaciations) can be caused by CO2 drawdown by weathering of LIP-related basalts."

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Climate feedbacks are also an important factor. Warming caused by LIPs could cause the destabilization of frozen methane clathrates, which then releases more greenhouse gases and causes more warming.

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