" How many tons of CO2 are released by the volcano s in activity in the world? Go a little courage, answer! " launches Jean-Paul Robert on the Facebook page. Taking his courage in both hands, Sciences et Avenir dared to rub shoulders with Jean-Paul's question so that scientific truth would come out into the open. Tremble, volcanoes!
" The most common question I was asked (and still asked) during my 30s and some years as a geochemist specialized in volcano gases by both than scientists working in areas other than vulcanology, is "do volcanoes emit more CO2 than human activities?" ". Terrance Gerlach, a researcher at the US Geological Survey, finally came to grips with this issue. And he finally answered "no" in a study published in 2011 in Eos, a publication of the American Union of Geophysics.
Human activities emit 150 times more CO2 than volcanoes
] Terrance Gerlach compiled all the studies that measured the gas emissions of contemporary volcanic eruptions. It has reached a range of between 100 million and 500 million tonnes of CO2 emitted each year. Thus, at the height of its exceptional eruption in 2010, the Icelandic volcano Eyjafjöll emitted between 150 and 300,000 tonnes per day.
Emissions from human activity are much higher. In 2017, they reached 36.8 billion tons 150 times more! Volcanic eruptions influence the global climate, but not by their greenhouse gas emissions, but by their sulfur particles. These billions of tons of dust are indeed shielding solar radiation and prevent it from reaching the lower layers of the atmosphere. Volcanoes have a cooling effect rather than warming. The June 1991 eruption of Pinatubo, a volcano in the Philippines, caused a global cooling of 0.6 ° C.