Shooting huge amounts of non-ozone-harming greenhouse gases into the atmosphere could counteract vast volcanic sulphur clouds that cause perpetual winters, new research suggests

The perpetual winters that follow giant volcanic eruptions could be avoided by shooting greenhouse gases into the atmosphere, according to new scientific research.

Deliberately interfering with the climate on a planetary scale, known as geoengineering, has until now been focused on counteracting global warming. One key geoengineering concept is to inject sulphur particles into the stratosphere to block sunlight and cool temperatures. But the likelihood of unexpected worldwide side effects have made geoengineering a very controversial idea.

Major volcanic eruptions naturally pump huge clouds of sulphur particles into the atmosphere and the giant eruption of Mount Tambora in Indonesia in 1815 dimmed the sun for several years around the world, leading to crop failures. Now, for the first time, scientists have analysed the idea of geoengineering to combat eruptions.

The work, published in Geophysical Research Letters, uses computer modelling and concludes it could be possible to counteract the climate effects of a Tambora-scale volcanic eruption by deliberately emitting greenhouse gases.

The researchers suggest a specific HFC gas could be used, as it only remains in the atmosphere for a few years, the same timescale as the volcanic sulphur. Also, HFC-152a does not destroy ozone, unlike its chemical cousins.

However, Professor Keith Shine, at the University of Reading and one of the research team, said: “We estimate that large quantities would be needed. This would be very expensive, and would require a vastly expanded industrial production capacity. Society would have to decide whether the risks associated with such a large volcanic eruption could ever justify this expense.”

The scientists calculate 1.25bn tonnes of HFC-152a would be needed in the first year. Today, just 150,000 tonnes of the most common related gas, HFC-1234a, are released each year.

“Considering such drastic action may appear far-fetched,” said Dr Jan Fuglestvedt, at the Center for International Climate and Environmental Research in Norway, and another member of the research team. “But it would be unwise for the scientific community and policymakers not to think the issue through. Future, large volcanic eruptions are inevitable.”

The study acknowledges “numerous practical, financial, scientific, philosophical and ethical issues.”

Other climatologists cautiously welcomed the research. “The possibility of deliberate intervention to ‘engineer’ our climate is undoubtedly scary, but climate change causes problems for both people and ecosystems, especially if it is large and rapid and whether it is warming or cooling,” said Prof John Shepherd, at the University of Southampton. “We need to be prepared, so far as possible, and explorations like this are desirable, even if some people find them distasteful.”

Prof Piers Forster, at the University of Leeds, said: “This is a great paper as it changes the perspective on geoengineering and as such reminds us what a ridiculous idea trying some technological fix to counter carbon dioxide could be.”

The enormous HFC injection into the atmosphere would keep temperatures from plummeting by trapping heat via the greenhouse effect. “Unfortunately this wouldn’t help with the major impact of large volcanoes on ecosystems which is changes in sunlight,” said Prof Peter Cox at the University of Exeter.