Uncovering the Mystery of Cryptic Carbon: How Volcanic Eruptions Shape Earth’s Climate

A recent study published in Nature Geoscience has shed light on the potential long-term effects of massive volcanic eruptions on Earth’s climate. Researchers have found evidence suggesting that even after surface eruptions cease, carbon dioxide (CO2) dissolved in underground magmas could slowly escape to the surface, contributing to prolonged periods of warming, slow climate recovery, and mass extinctions.

Large igneous provinces, regions where magma wells up to the surface, have been responsible for significant climate disruption throughout Earth’s history. These volcanic events have released large volumes of greenhouse gases like CO2 into the atmosphere, leading to temperature increases and major biological changes. The study’s lead author, Ben Black, a volcanologist at Rutgers University, emphasized the immense scale of these volcanic provinces, with eruptions capable of covering the continental U.S. half a kilometer deep in volcanic rocks.

One of the most notable examples of the impact of large igneous province eruptions is the Siberian Traps event 252 million years ago, which coincided with the end-Permian mass extinction, also known as the Great Dying. Despite the cessation of volcanic eruptions, temperatures and CO2 levels remained high for about 5 million years. Scientists have previously attributed these prolonged warming periods to weakened silicate weathering feedback, acting as a natural thermostat.

However, the new study proposes an alternative explanation for the extended warming periods following large igneous province eruptions. Using numerical models to simulate the climate response to carbon and nutrient cycle perturbations, researchers found that CO2 emissions solely from surface eruptions were insufficient to explain the prolonged warm periods. The study suggests that carbon continued to leak from the volcanoes after the eruptions ceased, contributing to the extended warming observed in the aftermath.

The researchers’ simulations showed that as magma rises and cools, dissolved CO2 can escape even when the magma itself cannot. This “cryptic carbon” release could last for millions of years after surface eruptions end, impacting biological recovery following mass extinctions. The findings have implications for understanding the effects of present-day warming and human-induced carbon emissions, providing insights into how the planet may recover from abrupt disruptions.

Overall, the study highlights the complex interactions between volcanic activity, climate change, and mass extinctions throughout Earth’s history. By uncovering the role of cryptic carbon in prolonged warming periods, researchers are advancing our understanding of the long-term impacts of volcanic eruptions on the planet’s climate and ecosystems.