When two disasters saved Earth from a worse one

In June 1991 the Philippine volcano, Mount Pinatubo, exploded producing one of the greatest volcanic eruptions in the 20th Century.

But what is less commonly known is that if Typhoon Yunya hadn’t coincided with the eruption, the impact could have been significantly worse.

It is well known that ththe Pinatubo eruption, which killed around 800 people and left 10,000 homeless, ejected so much dust into the atmosphere that it had a major effect on climate, depressing global temperatures by around 0.5°C for a couple of years.

Along with all the magma and ash, vast quantities of hydrogen chloride were pumped out of Pinatubo. Had this hydrogen chloride reached the stratosphere it would have initiated chemical reactions with chlorine (which is increased thanks to all chlorofluorocarbons – CFCs – we have pumped out) and massively thinned Earth’s ozone layer.

But luckily Typhoon Yunya powered its way through the eruption plume and washed most of the hydrogen chloride out before it got anywhere near the stratosphere.

Next time we might not be so lucky. New research suggests that future Pinatubo-like eruptions would likely cause serious thinning of the ozone layer, having a significant impact on skin cancer rates, livestock mortality and crop yields.