Bbc Inside Science

Why was the blast from the Hunga-Tonga-Hunga-Ha'apai volcano so explosive? Where are we on the global climatic thermostat? And how you can get involved in the Big Repair Project.Gaia Vince speaks with Auckland University volcanologist Prof Shane Cronin, one of the few human beings to have visited the now-disappeared volcanic land bridge that stretched until last week between the islands of Hunga-Tonga and Hunga-Ha'apai. It was destroyed in the disastrous eruption of the volcano beneath it last week that has wrought such devastation to the nation of Tonga, and whose effects were felt in the Americas and detectable all around the world. Why was this submarine eruption quite so explosive, given that the eruption itself was not one of the biggest or longest in living memory?Previous eruptions - notably Mount Pinatubo in the Philippines in 1991 - released huge amounts of particles and sulphates into the stratosphere such that they had a cooling effect on the atmosphere globally, lasting 2-3 years. Prof Richard Bet