Catastrophic changes Planet Earth is undergoing today likely mirror many of those which happened hundreds of millions of years ago. The big difference? Volcanoes - not humans - were likely the main drivers of the changes back then.
The amount of CO2 released into the end-Triassic atmosphere from volcanic eruptions was likely comparable to the projected total amount of anthropogenic (manmade) CO2 that will be emitted during the 21st century. The findings are published in Nature Communications. Such large volumes of volcanic CO2 likely contributed to end-Triassic global warming, sea level rise, and ocean acidification.
The end-Triassic extinction (approximately 201 million years ago) resulted in the demise of large proportions of all marine and terrestrial species. It is thought that this extinction was caused by dramatic climate change and rising sea levels which, are known to have occurred at that time. Volcanic CO2 released during the large volume Central Atlantic Magmatic Province eruptions has been considered as an important contributor to the process, but this is debated.
Manfredo Capriolo and colleagues found evidence of abundant CO2 in basaltic rocks from the end-Triassic Central Atlantic Magmatic Province, by analysing tiny gas exsolution bubbles preserved within the rocks. The authors used their analyses to estimate the total volume of volcanic CO2 released during these eruptions. They found that one eruption phase (100,000 km3 of lava over 500 years) is likely to have emitted a total volume of CO2 equivalent to that projected from anthropogenic activities during the 21st century, in the 2⁰ C warming scenario.
The authors suggest that the end-Triassic climatic and environmental changes, driven by the large volume volcanic CO2 emissions, may have been similar to those predicted for the near future under anthropogenic warming.