Climate change could cause heavier rainfall on volcanoes

Climate change could cause more extreme rainfall at most of Earth's active land-based volcanoes. Previously, rainfall has been implicated as a risk factor for eruptions and landslides.

The geological record is littered with volcanoes that change Earth's climate by spewing out gases and soot that reflect or trap radiation from the sun. For example, the eruption of Mount Tambora in 1815 cooled global temperatures so much that it made 1816 the "year without a summer." The relationship seems to go both ways: melting glaciers, rising sea levels and rainfall can affect volcanic activity.

Jamie Farquharson of the University of Strasbourg in France and Falk Amelung of the University of Miami in Florida wondered how many of Earth's roughly 1,200 active volcanoes might receive increased rainfall due to climate change.

The pair ran nine different climate models under medium and high greenhouse gas emissions scenarios, corresponding to 2-3ºC and 5ºC of warming by 2100. They then looked at were at least seven of the nine models matched.

Under the high-emissions scenario, they found that 716 volcanoes would see an increase in heavy rainfall, including most of the Ring of Fire in the Pacific, the East African Rift system, and some volcanic island chains in Antarctica and the Pacific. In the medium emissions scenario, 506 volcanoes would be affected.

In both scenarios, about a hundred volcanoes would see a decrease in heavy rainfall by the year 2100. There were also several hundred in each scene where the models did not agree well enough to make a determination.

The researchers also analyzed decades of reports from the Smithsonian Institution's Global Volcanism Program, which catalogues volcanic activity. They found that heavy rains had been implicated in eruptions or other hazards such as landslides at least 174 volcanoes, including Mount Vesuvius in Italy, Mount St. Helens in Washington, and Mount Reventador in Ecuador, all of which would receive more heavy rain with The warm-up.

Thomas Aubry of the University of Cambridge says this "puts the nail in the coffin for how important rainfall will be for volcanic hazards."

Heavy rains can induce eruptions when cold water seeps into lava domes and vaporizes, or by "rotting" a volcano's internal structure over time, says Bill McGuire of University College London. Heavy rains can also cause volcanic ash mudslides called lahars, which are the deadliest volcanic hazard. "Volcanoes tend to be quite fragile environments," says Farquharson.

Aubry says the conditions under which increased precipitation would trigger an eruption or lahar are complex and "could change a lot from volcano to volcano." But the study shows that rainfall should be considered as part of volcanic hazard monitoring, he says. The monitors of many volcanoes do not usually take into account meteorological data.

According to scientists, most active subaerial volcanic systems in the Holocene are expected to experience more intense rainfall as global temperatures continue to rise.

For every degree of warming over the next 80 years, intense precipitation is expected to increase by up to 46% in some volcanic regions, consistent with a high emissions climate future.

Another 33% of the world's volcanoes lack adequate model agreement to make predictions about whether future rainfall will be more or less intense.

These findings are consistent with many emission scenarios and suggest important attendant consequences for fallout-associated hazards in most subaerial volcanic systems on Earth.

The authors can look at how the Earth system has reacted to short- and long-term climate changes in the past to learn more about the coming years, where global warming of 1.5 to 2o C by 2100 appears to be a done deal.

Support us to keep independent environmental journalism alive in India.

Keep Reading

MP farmers battle stray animals, sleepless nights to protect crops

Indore’s Pipliyahana Lake struggles to survive, even after conservation measures

Costliest water from Narmada is putting financial burden on Indore

Changing weather pattern impacts soybean crops in Dewas region of MP

Follow Ground Report on X, Instagram and Facebook for environmental and underreported stories from the margins. Give us feedback on our email id [email protected]. 

Don't forget to Subscribe to our weekly newsletter, Join our community on WhatsApp, Follow our Youtube Channel for video stories.