Climate change could cause heavier rainfall on volcanoes

James Dinneen is a writer.

The majority of Earth's active land volcanoes could be affected by climate change. The risk of eruptions and mud slides has been linked to the amount of rain.

1816 was the year without a summer because of the eruption of Mount Tambora, one of many volcanic eruptions that change Earth's climate. Climate change and sea level rise can affect volcanic activity.

Jamie Farquharson at the University of Strasbourg in France and Falk Amelung at the University of Miami in Florida wondered how many active land volcanoes might get an increase in precipitation due to climate change.

The pair ran nine different climate models under different greenhouse gas emission scenarios to show how warming will occur by the year 2200. They looked at where most of the models agreed.

In the high emissions scenario, 716 volcanoes would see an increase in heavy rain, including most of the Pacific "Ring of Fire", and in the medium emissions scenario, 509 volcanoes would see an increase in precipitation.

Around a hundred volcanoes would see a decrease in the amount of rain by the year 2200. The models didn't agree enough to make a determination in many scenarios.

The researchers looked at reports from the Global Volcanism Program. They found that at least 174 volcanoes, including Mount Vesuvius in Italy, were linked to eruptions and mudslides because of heavy precipitation.

The nail in the coffin for how important rainfall is going to be for volcanic hazard was put in this.

Bill McGuire, a volcanologist at University College London, says that cold water can cause eruptions when it comes into contact with lava domes or the internal structure of a volcano. Lahars, the most deadly volcanic hazard, can be caused by heavy rains. Farquharson says that volcanos tend to be fragile.

The conditions under which an eruption or a lahar could happen are complex and could change from one volcano to another. The study shows that rain should be included in volcanic hazard monitoring. Monitors at many volcanos don't usually take meteorological data into account.

The journal was published by the Royal Society Open Science.