A study by an international team of geological scientists has revealed the unseen source that could explain the duration of certain episodes of climate change.
A study has revealed the source influencing the sudden warming of the Earth
“Our findings are important because they identify a hidden source of CO2 in the atmosphere during times of sudden warming of the Earth’s climate, which lasted much longer than we expected.”explained Benjamin Black, a volcanologist at Rutgers University-New Brunswick in the United States, who coordinated the study carried out by an international team of specialists in geological sciences.
“We believe we have found a key piece of the puzzle of how Earth’s climate was disrupted and, perhaps just as importantly, how it recovered“, continued Benjamin Black, in a press release that accompanies the publication of the study in the journal Nature Geoscience.
“Large-scale eruptive provinces” (“Large igneous province” – LIP), vast regions formed by massive eruptions of magma in a short geological period, are associated with four of the five major mass extinctions that occurred after the appearance of complex life forms on Earth .
These eruptions released huge amounts of gases into the atmosphere, especially CO2 and methane, leading to global warming and ocean acidification.
252 million years ago, at the end of the Permian, intense volcanic activity in one of these LIPs, called the “Siberian Traps”, led to the most severe episode of biodiversity loss in the history of our planet. More than 90% of marine species and 70% of terrestrial species have disappeared.
The greenhouse effect, the high concentration of CO2 and the disruption of the carbon cycle persisted for about five million years, that is, about three million years after the end of the period of volcanic activity.
This slower-than-expected climate recovery based on climate and bio-geo-chemical models has long intrigued scientists.
Are there certain thresholds beyond which natural climate regulation systems begin to fail? And if not, then how can we explain the fact that these episodes last much longer than the volcanic activity that caused them?
anthropogenic CO2
The study’s authors compiled chemical analyzes of lava samples, developed computer models that simulated melting inside the Earth, and compared the results to climate archives preserved in sedimentary rocks before advancing the hypothesis that the phase of surface volcanic activity was not in fact the only one. which released CO2.
Even when the eruptions stopped, magma production continued deep in the Earth’s crust and mantle, and continued to release CO2, leading to prolonged climate warming.
If the hypothesis of this source “hidden” of carbon dioxide will be confirmed, it could mean that “thermostat“The Earth works better than scientists thought, argue the authors of the study.
This type of volcanism “it certainly cannot explain current climate change“, said Benjamin Black, however.
This “rare and exceptionally large phenomenon capable of mobilizing enough magma to cover the continental United States or Europe with a layer of lava half a kilometer thick“, last occurred on Earth 16 million years ago, he points out.
Currently, the carbon released into the atmosphere by all the volcanoes on Earth together represents “less than 1%” of CO2 emissions related to human activities, explained the American volcanologist.
“Our study suggests that Earth’s climate control systems continue to function even under extreme conditions” Benjamin Black added. This gives the study coordinator “the hope that geological processes will be able to gradually remove anthropogenic CO2 from atmosphereeven if it will take hundreds of thousands to millions of years”.
