London (AFP)

Global warming will accentuate the consequences of large-scale volcanic eruptions, amplifying the temporary cooling following this type of event, British researchers warned Thursday.

"Large-magnitude eruptions will have greater effects as the climate continues to warm," said researchers from Cambridge University and the British Meteorological Agency (Met office) in a statement.

According to their study, which will be published in the journal Nature Communications, plumes of ash and gas emitted by large volcanic eruptions will rise higher and higher in the atmosphere, and volcanic material linked to the eruptions will spread more rapidly over the earth. world.

The combined effect of these two phenomena will further prevent sunlight from reaching the Earth's surface, which "will greatly amplify the effects of temporary cooling" occurring after an eruption, an increase of around 15%.

For example, the eruption of Mount Pinatubo in the Philippines in 1991 and its plume - the second largest of the twentieth century - rocked the entire planet, causing global temperatures to drop by 0.5 ° C in 1992.

Eurption of Mount Pinatubo, June 12, 1991 in the Philippines ARLAN NAEG AFP / Archives

On the other hand, for smaller eruptions as it occurs every year, a strong global warming would reduce by 75% the effects of temporary cooling.

Melting ice caps are also expected to "increase the frequency and size of volcanic eruptions in places like Iceland," the researchers said.

"Climate change is not a phenomenon to come, it is already here, as the IPCC report published this week clearly demonstrates," warned researcher Anja Schmidt, co-author of the study.

This report by UN climate experts, released on Monday, says global warming is happening much faster than expected and that humans, "unquestionably" responsible, have no choice but to drastically cut emissions greenhouse gases, if they want to limit the damage.

Global warming: the key points of the IPCC report Alain BOMMENEL AFP

He also considered "likely" that at least one large volcanic eruption would occur in the 21st century, saying it "would reduce temperatures for one to three years, especially on land, and change extreme precipitation."

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