In the world there are 1,500 active volcanoes without counting the unknown number of these mountains that are under the oceans. Each day, one or two dozen of them erupt somewhere in the world. The vision of one of these giants spewing lava, ash and smoke is frightening. But what if all started erupting at the same time? This question was asked to Parv Sethi, a geologist at Radford University in Virginia (USA) on LiveScience website. If such a thing happened Earth would not be able to survive, as a succession of environmental disasters even worse than a nuclear winter would trigger. But to our relief, the probability that something like that happened is so small that researchers consider it impossible.
But imagine for a moment the consequences of that cataclysm. ‘Things will become so bad that I wouldn’t want to survive on an Earth like this’, admits Sethi to Live Science. The biggest problem would be in the ashes and volcanic gases, cause we have to bear in mind that although some volcanoes do not have much strength, others like Yellowstone already pose a great threat by themselves, so 1500 at the same time is a global bombing. A thick layer of ash would engulf the planet, preventing sunlight from reaching the surface. A complete darkness would wrap us, plants would not be able to perform photosynthesis, crops would be destroyed and a drastic climate change would occur.
How long would this exceptional state last? According to Sethi, ash would remain in the atmosphere for up to 10 years. Acid rain caused by volcanic gases would kill any crop that survived ashes and contaminate groundwater and ocean surface. Farewell to coral and sea creatures with hard shells, goodbye to fish and other marine life.
Volcanic eruptions release carbon dioxide, a greenhouse gas, which could help compensate the global cooling caused by ash and stratospheric particles. But 1500 eruptions at the same time would be like entering an oven.
The only beings that would survive in these conditions are extremophiles that live in very acidic environments such as hot springs in Yellowstone or undersea deep vents, protected from the devastation of the surface. For humans, it could be saved (at least for some time) those which are orbiting the planet or perhaps in well prepared underground bunkers but Sethi says that if this great world eruption occurs ‘the lucky ones would be the dead ones’.