Plan to avert global warming by cooling planet artificially 'could cause climate chaos'

Proposal to inject tiny reflective particles into the upper atmosphere to block out sunlight could lead to droughts, warn scientists

Science Editor

A controversial proposal to cool the planet artificially by injecting tiny reflective particles into the upper atmosphere which block out sunlight would cause droughts and climate chaos in the poorest countries of the world, a study has found.

One of the more serious plans to “geoengineer” the global climate would in effect create another climate catastrophe that would result in misery for millions of people, according to a computer model of the plan.

Some climate researchers have suggested that mimicking the cooling effects of volcanic eruptions with massive injections of sulphate particles into the atmosphere may be necessary in an emergency if global temperatures and carbon dioxide levels continue to rise unabated.

It is known that the sulphate particles produced by volcanoes, which are relatively quickly washed out of the atmosphere, can reduce incoming solar radiation significantly, and so cause average global temperatures to dip.

However, a study by scientists at Reading University has found that the effect of a massive and continuous injection of sulphates into the air would be to alter the rainfall patterns over vast regions of the world, notably Africa, South America and Asia which could as a result be devastated by drought.

“We have shown that one of the leading candidates for geo-engineering could cause a new unintended side-effect over a large part of the planet,” said Andrew Charlton-Perez of the University of Reading, a co-author of the study published in the journal Environmental Research Letters.

“The risks from this kind of geo-engineering are huge. A reduction in tropical rainfall of 30 per cent would, for example, quickly dry out Indonesia so much that even the wettest years after a man-made intervention would be equal to drought conditions now,” Dr Charlton-Perez said.

“The ecosystems of the tropics are among the most fragile on Earth. We would see changes happening so quickly that there would be little time for people to adapt.

“Discussion of geo-engineering often prompts heated debate, but very often there is a lack of understanding of what putting large amounts of aerosol in the stratosphere will do to the complex climate system. Our findings should help to fill in some of the gaps about one of the leading candidates,” he said.

Volcanoes, such as the Mount Pinatubo eruption in 1991, can cool average global temperatures significantly for short periods, but to reverse the expected 4C rise in global temperatures as a result of global warming would need large quantities of sulphate aerosols to be injected into the upper atmosphere over the course of several years.

“To reduce global temperatures enough to counter effects of global warming would require a massive injection of aerosol – the small particles that reflect sunlight back into space. This would be equivalent to a volcanic eruption five times the size of that of Mount Pinatubo every year,” said Angus Ferraro of Exeter University.

“Previous predictions of how stratospheric aerosol injection would affect climate were based on a number of assumptions. By actually modelling what would happen if aerosol were to be pumped into the atmosphere around the equator, we have revealed a new impact of geo-engineering on tropical climate,” Dr Ferraro said.

“As well as reflecting some of the incoming energy from the sun and cooling surface temperature, the aerosol also absorbs some of the heat energy coming from the surface which warms the stratosphere. We have shown for the first time that warming the stratosphere makes the troposphere below more stable, weakening upward motion and reducing the amount of rainfall at the surface,” he said.

Professor Ellie Highwood of University of Reading, a co-author of the study said that there is an understandable desire to explore alternatives to deep-cuts in carbon dioxide emissions, which do not seem to be materialising as a result of the failure of countries to reach a binding international agreement.

“Climate scientists agree that cutting carbon emissions is still necessary to curb the damaging effects of future climate change. However, since such cuts are far from certain to materialise, proponents of geo-engineering research argue that whatever the world decides on its carbon emissions, it would be prudent to explore alternatives that might help us in the decades ahead,” Professor Highwood said.

“On the evidence of this research, stratospheric aerosol geo-engineering is not providing world leaders with any easy answers to the problem of climate change,” she said.

Start your day with The Independent, sign up for daily news emails
Life and Style
Steve Shaw shows Kate how to get wet behind the ears and how to align her neck
healthSteven Shaw - the 'Buddha of Breaststroke' - applies Alexander Technique to the watery sport
Arts and Entertainment
The sight of a bucking bronco in the shape of a pink penis was too much for Hollywood actor and gay rights supporter Martin Sheen, prompting him to boycott a scene in the TV series Grace and Frankie
tv
Sport
footballShirt then goes on sale on Gumtree
Voices
Terry Sue-Patt as Benny in the BBC children’s soap ‘Grange Hill’
voicesGrace Dent on Grange Hill and Terry Sue-Patt
Arts and Entertainment
Performers drink tea at the Glastonbury festival in 2010
music
Arts and Entertainment
Twin Peaks stars Joan Chen, Michael Ontkean, Kyle Maclachlan and Piper Laurie
tvName confirmed for third series
Sport
Cameron Jerome
footballCanaries beat Boro to gain promotion to the Premier League
Arts and Entertainment
art
News
ebookA unique anthology of reporting and analysis of a crucial period of history
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Guru Careers: Software Developer / C# Developer

£40-50K: Guru Careers: We are seeking an experienced Software / C# Developer w...

Guru Careers: Software Developer

£35 - 40k + Benefits: Guru Careers: We are seeking a Software Developer (JavaS...

SThree: Trainee Recruitment Consultant / Resourcer

£18000 - £23000 per annum + Commission: SThree: As a Trainee Recruitment Consu...

Ashdown Group: UI Developer - (UI, HTML, CSS, JavaScript, AngularJS)

£25000 - £40000 per annum: Ashdown Group: UI Developer - (UI, JavaScript, HTML...

Day In a Page

Abuse - and the hell that came afterwards

Abuse - and the hell that follows

James Rhodes on the extraordinary legal battle to publish his memoir
Why we need a 'tranquility map' of England, according to campaigners

It's oh so quiet!

The case for a 'tranquility map' of England
'Timeless fashion': It may be a paradox, but the industry loves it

'Timeless fashion'

It may be a paradox, but the industry loves it
If the West needs a bridge to the 'moderates' inside Isis, maybe we could have done with Osama bin Laden staying alive after all

Could have done with Osama bin Laden staying alive?

Robert Fisk on the Fountainheads of World Evil in 2011 - and 2015
New exhibition celebrates the evolution of swimwear

Evolution of swimwear

From bathing dresses in the twenties to modern bikinis
Sun, sex and an anthropological study: One British academic's summer of hell in Magaluf

Sun, sex and an anthropological study

One academic’s summer of hell in Magaluf
From Shakespeare to Rising Damp... to Vicious

Frances de la Tour's 50-year triumph

'Rising Damp' brought De la Tour such recognition that she could be forgiven if she'd never been able to move on. But at 70, she continues to flourish - and to beguile
'That Whitsun, I was late getting away...'

Ian McMillan on the Whitsun Weddings

This weekend is Whitsun, and while the festival may no longer resonate, Larkin's best-loved poem, lives on - along with the train journey at the heart of it
Kathryn Williams explores the works and influences of Sylvia Plath in a new light

Songs from the bell jar

Kathryn Williams explores the works and influences of Sylvia Plath
How one man's day in high heels showed him that Cannes must change its 'no flats' policy

One man's day in high heels

...showed him that Cannes must change its 'flats' policy
Is a quiet crusade to reform executive pay bearing fruit?

Is a quiet crusade to reform executive pay bearing fruit?

Dominic Rossi of Fidelity says his pressure on business to control rewards is working. But why aren’t other fund managers helping?
The King David Hotel gives precious work to Palestinians - unless peace talks are on

King David Hotel: Palestinians not included

The King David is special to Jerusalem. Nick Kochan checked in and discovered it has some special arrangements, too
More people moving from Australia to New Zealand than in the other direction for first time in 24 years

End of the Aussie brain drain

More people moving from Australia to New Zealand than in the other direction for first time in 24 years
Meditation is touted as a cure for mental instability but can it actually be bad for you?

Can meditation be bad for you?

Researching a mass murder, Dr Miguel Farias discovered that, far from bringing inner peace, meditation can leave devotees in pieces
Eurovision 2015: Australians will be cheering on their first-ever entrant this Saturday

Australia's first-ever Eurovision entrant

Australia, a nation of kitsch-worshippers, has always loved the Eurovision Song Contest. Maggie Alderson says it'll fit in fine