Volcanic emissions played a direct role in the extreme climate change that led to the extinction of almost half of all species at the end of the Triassic period 201 million year ago, according to a new study.
The amount of carbon dioxide released into the atmosphere from these volcanic eruptions is comparable to the amount of CO2 scientists expect all human activity in the 21st century to produce.
Researchers have long thought that dramatic climate change and rising sea levels caused the end-Triassic extinction. While there was large-scale volcanic activity at the time, known as the Central Atlantic Magmatic Province eruptions, experts have debated the role it played in directly contributing to the extinction event.
As reported in Nature Communications, researchers found evidence of bubbles of carbon dioxide trapped in volcanic rocks dating to the end of the Triassic, supporting the theory that volcanic activity contributed to the devastating climate change believed to cause the mass extinction.
The researchers suggest that the end-Triassic environmental changes driven by volcanic carbon dioxide emissions may have been similar to those predicted for the near future.
After analyzing the tiny gas exsolution bubbles preserved within the rocks, the team estimates that the amount of carbon emissions released in a single eruption—comparable to 100,000 km3 of lava spewed over 500 years—is likely equivalent to the total that all human activity during the 21st century will produce, assuming a 2 degrees C (3.6 degrees F) rise in global temperature above pre-industrial levels.
“Although we cannot precisely determine the total amount of carbon dioxide released into the atmosphere when these volcanoes erupted, the correlation between this natural injection of carbon dioxide and the end-Triassic extinction should be a warning to us,” says Don Baker, professor of earth and planetary sciences at McGill University.
“Even a slight possibility that the carbon dioxide we are now putting into the atmosphere could cause a major extinction event is enough to make me worried.”
Source: McGill University