Volcanoes: Sometimes they cool & sometimes they heat

by | December 1, 2024, 8:06 PM | Earth Science

An international team of geoscientists journeyed to northeastern Oregon, where massive volcanism has been linked with climate warming 16 million years ago. For their study, the scientists zeroed in the Wallowa Mountains, which are laced with enormous sheets of flat magmatic dikes, created when molten rock flowed into cracks and solidified. Credit: Benjamin Black/Rutgers University

Volcanoes have played a role in mass extinctions at multiple times in our planet’s geologic history.  Exactly how they kill off everything is dependent on the rapidity with which they erupt. If the eruptions are brief, sulfates and other particulates will fill the atmosphere and reflect sunlight, causing more cooling. If, instead, things occur over long periods of time, particles won’t build up in sufficient numbers to cool us off, while the release of carbon dioxide will lead to greenhouse gas related heating. If that is confusing, all you need to know is massive short lived eruptions make for a cold world, and slow long lived eruptions make for a hot world. 

And, slow, carbon dioxide releasing eruptions are just what happened at the end of the Permian age, 252 million years ago. 

If you want to scare yourself, google the Siberian Traps. Essentially, a massive swath of Siberia became a massive volcano for a while. And this wasn’t just casual eruptions – enough Lava was emitted that it could have covered the continental US in half a kilometer of lava. 

And if that’s not bad enough, even when the volcanoes had stopped emitting lava, they continued to emit carbon dioxide, perhaps for millions of years. New research shows how this happened with the end permian extinction event, and perhaps also at other times in Earth’s history where periods of warming couldn’t be easily explained.

In addition to explaining mass die-offs, these results also show that our planet can bounce back from warming periods triggered by the release of carbon dioxide.

This work appears in Nature Geoscience and is led by Benjamin Black. According to Black, “Our findings are important because they identify a hidden source of CO2 to the atmosphere during moments in Earth’s past when climate has warmed abruptly and stayed warm much longer than we expected. We think we have figured out an important piece of the puzzle for how Earth’s climate was disrupted, and perhaps just as importantly, how it recovered. If this is true, it could be good news for Earth’s recovery after human-driven climate warming. It means that if we stop turning the thermostat up, on geologic timescales of hundreds of thousands to millions of years, climate can recover.”

So, how about we turn down CO2 levels and run an experiment to see just how long it will take for our world to return to normal?

References