The Hunga-Tonga-Hunga-Ha'apai volcano erupted without warning. At first, Mere Taufa thought bombs were going off in the city of Nuku'alofa. 

Then the afternoon sky darkened as a cloud of smoke and ash rose 12 miles into the sky. "You could just hear screams everywhere," says Mere. 

Soon, huge waves were hitting the coast of Tonga. Hours later, waves flooded car parks on the coast of California 5,000 miles away. In Japan, 230,000 people were told to leave their homes.

Warnings were also issued in New Zealand, Australia, Hawaii and Alaska. Shock waves were registered 10,000 miles away in Britain. 

Tonga is not the only place in danger of volcanoes. Last September an eruption in the Canary Islands destroyed 200 homes. On Wednesday the Wolf Volcano in the Galapagos islands erupted. 

In 1815 Mount Tambora in Indonesia threw so much ash into the atmosphere that in some places it blotted out the sun. Temperatures fell and crops failed. Some called 1816 "The Year Without a Summer".

But now some scientists believe this could help us fight climate change.

In 1991, the eruption of Mount Pinatubo in the Philippines released millions of tons of sulphur dioxide into the atmosphere. These created tiny drops of moisture that scattered the sun's rays and reflected some of them back. The Earth's average temperature fell by 0.5C the following year.

It is possible that other volcanoes could have the same effect if we find ways to make them erupt. But if things go wrong, we could experience another "Year Without a Summer" - or worse.

Yes: Climate change is a critical problem and anything that might halt it is worth trying. If one volcano can lower Earth's temperature by 1C, a few eruptions could solve all our problems.

No: Volcanoes are incredibly dangerous, in terms of both the lava and ash they produce and the tsunamis they can trigger. Causing an eruption could have terrible consequences across the world.

Or... We should try to mimic the effects of a volcanic explosion without actually causing one. We could disperse sulphur dioxide high up in the stratosphere just as Mount Pinatubo did.