Add another entry to the ever-lengthening list of apocalyptic scenarios global warming might bestow upon Earth: massive volcanic eruptions all around the world.
In a recent study published in the science journal Geology, researchers show that historically, following periods of great glacial melt, the world subsequently experienced years of major volcanic eruptions. In some regions, as in Costa Rica, volcanic activity spiked five to 10 times. Remember, periods of severe volcanic activity are potential extinction events—increasing eruptions tenfold is something we'd clearly rather have not happen.
Researchers' working theory for why it might goes something like this: When tremendously heavy glaciers melt, they release pressure on the continents. Simultaneously, all that melting ice leads to rising sea levels, which increases pressure on the ocean crust. This, evidently, is a recipe for setting off volcanic activity.
"We propose that this variability in volcanic activity results from crustal stress changes associated with ice age mass redistribution," the study explains. "In particular, increased volcanism lags behind the highest rate of increasing eustatic sea level (decreasing global ice volume) … and correlates with numerical predictions of stress changes at volcanically active sites."
The scientists were able to build a model that predicted the jump in activity in aforementioned Costa Rica, home to the world-renowned Ring of Fire. And the model was meticulously built with hundreds of thousands of years' worth of volcanic historical data.
Volcanologist and lead author Dr. Steffen Kutterolf says that, "Among others pieces of evidence, we have observations of ash layers in the seabed and have reconstructed the history of volcanic eruptions for the past 460,000 years." And lo and behold, "There were periods when we found significantly more large eruptions than in others" says Kutterolf, the lead author of the Geology report.
Now, this isn't a new assertion; we've seen plenty of speculation that climate change-driven ice melt may mess with plate tectonics, causing earthquakes and volcanism. But we haven't seen such a detailed investigation into the relationship between ice melt and volcanoes, and the correlation evidenced here is pretty convincing.
Even so, this isn't really going to top off the list of climate concerns anytime soon—researchers found a lag time of around 2,500 years between the vanishing glaciers and the volcanic Ragnarok. For now, let's stick to bracing for the spread of infectious diseases, the rampant droughts, the coast-swallowing rising seas, and the violent frankenstorms, shall we?