Erupting Bali volcano materials could alleviate climate change, scientists hope
Erupting materials being spewed into the atmosphere by Indonesia’s Mount Agung volcano could prove to negate the effects of climate change, according to scientists.
A team from Cornell University is preparing to study just how much the eruption will cool the earth and whether this effect could be replicated in order to alleviate some of the effects of man-made climate change.
Douglas MacMartin, senior lecturer in mechanical and aerospace engineering at Cornell University, has authored a series of recent papers on how to mimic volcanoes by injecting sulphur dioxide into the stratosphere.
He believes the process, known as geo-engineering, could mitigate the effects of climate change and the Agung eruption could provide some important lessons for the method.
“Large volcanic eruptions, such as Mt. Pinatubo in 1991 and perhaps Agung in 2017 if it is large enough, cool the planet for a year or more by putting sulphur dioxide into the stratosphere where it forms sulphate aerosols that reflect sunlight,” he said.
“In principle, humans could deliberately do the same thing to help manage some impacts of climate change, an idea referred to as geo-engineering.
“There are a lot of concerns and uncertainties surrounding this idea, but we may be able to learn something about this from observing the stratospheric response to the Agung eruption, which would help improve how climate models represent processes such as sulphate aerosol formation and upper atmospheric chemistry.”
Ash and smoke ejected so far by the Agung volcano, which has been erupting in recent days, has not been big enough or high enough in the atmosphere to cool world temperatures.
Scientists are using it as an opportunity to study what would happen if the volcano had a much larger eruption, such as the one that occurred in 1963.
It is estimated that Agung spewed eight million tonnes of sulphur dioxide into the stratosphere in 1963, about 10-15 kms above the Earth’s surface, which was enough to trim world temperatures for months. That eruption also killed more than 1,000 people in Bali.
Satellite measurements of eruptions have only recently become precise enough to exploit volcanoes as models for geo-engineering.
That was impossible, for instance, when Mount Pinatubo in the Philippines erupted in 1991 and blew about 20 million tonnes of sulphur dioxide into the stratosphere, the second biggest eruption of the 20th century after one in Alaska in 1912.
Mount Pinatubo had a cooling effect on the Earth because the sun-dimming sulphur spread worldwide.
“Since Pinatubo we’ve got a lot better at measuring the effects of big eruptions”, said Matthew Watson of the University of Bristol. “We’re waiting for something to happen on a scale where we can start thinking about what it means for geo-engineering.”
He estimated that the Agung volcano has probably ejected only about 10,000 tonnes of sulphur dioxide in the latest eruption and has not reached as high as the stratosphere.
Governments agree they should focus most on cutting greenhouse gas emissions under the 2015 Paris Agreement rather than on science-fiction-like short-cuts to limit temperatures blamed for causing more heatwaves, floods and rising sea levels.
However, current policies still put the world on track to overshoot the Paris goal of limiting rising temperatures to “well below” two degrees Celsius above pre-industrial times.