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
Voices
Lucerne’s Hotel Château Gütsch, one of the lots in our Homeless Veterans appeal charity auction
charity appeal
Life and Style
A woman walks by a pandal art installation entitled 'Mars Mission' with the figure of an astronaut during the Durga Puja festival in Calcutta, India
techHow we’ll investigate the existence of, and maybe move in with, our alien neighbours
Arts and Entertainment
Tony Hughes (James Nesbitt) after his son Olly disappeared on a family holiday in France
tv
News
people

Jo from Northern Ireland was less than impressed by Russell Brand's attempt to stage a publicity stunt

PROMOTED VIDEO
Sport
Nabil Bentaleb (centre) celebrates putting Tottenham ahead
footballTottenham 4 Newcastle 0: Spurs fans dreaming of Wembley final after dominant win
Arts and Entertainment
The Apprentice candidates Roisin Hogan, Solomon Akhtar, Mark Wright, Bianca Miller, Daniel Lassman
tvReview: But which contestants got the boot?
Arts and Entertainment
Jim Carrey and Jeff Daniels ride again in Dumb and Dumber To
filmReview: Dumb And Dumber To was a really stupid idea
Arts and Entertainment
Sir Ian McKellen tempts the Cookie Monster
tvSir Ian McKellen joins the Cookie Monster for a lesson on temptation
News
i100
Travel
Tourists bask in the sun beneath the skyscrapers of Dubai
travelBritish embassy uses social media campaign to issue travel advice for festive holiday-makers in UAE
News
ebooksNow available in paperback
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

Ashdown Group: Helpdesk Analyst

£25000 per annum: Ashdown Group: An established media firm based in Surrey is ...

Ashdown Group: Java Developer - Hertfordshire - £47,000 + bonus + benefits

£40000 - £470000 per annum + bonus: Ashdown Group: Java Developer / J2EE Devel...

Ashdown Group: Head of Finance - Financial Director - London - £70,000

£70000 per annum: Ashdown Group: Head of Finance - Financial Controller - Fina...

Recruitment Genius: Business Development Executive - Nationwide - OTE £65,000

£30000 - £65000 per annum: Recruitment Genius: This small technology business ...

Day In a Page

Jeb Bush vs Hillary Clinton: The power dynamics of the two first families

Jeb Bush vs Hillary Clinton

Karen Tumulty explores the power dynamics of the two first families
Stockholm is rivalling Silicon Valley with a hotbed of technology start-ups

Stockholm is rivalling Silicon Valley

The Swedish capital is home to two of the most popular video games in the world, as well as thousands of technology start-ups worth hundreds of millions of pounds – and it's all happened since 2009
Did Japanese workers really get their symbols mixed up and display Santa on a crucifix?

Crucified Santa: Urban myth refuses to die

The story goes that Japanese store workers created a life-size effigy of a smiling "Father Kurisumasu" attached to a facsimile of Our Lord's final instrument of torture
Jennifer Saunders and Kate Moss join David Walliams on set for TV adaptation of The Boy in the Dress

The Boy in the Dress: On set with the stars

Walliams' story about a boy who goes to school in a dress will be shown this Christmas
La Famille Bélier is being touted as this year's Amelie - so why are many in the deaf community outraged by it?

Deaf community outraged by La Famille Bélier

The new film tells the story of a deaf-mute farming family and is being touted as this year's Amelie
Calls for a military mental health 'quality mark'

Homeless Veterans campaign

Expert calls for military mental health 'quality mark'
Racton Man: Analysis shows famous skeleton was a 6ft Bronze Age superman

Meet Racton Man

Analysis shows famous skeleton was a 6ft Bronze Age superman
Garden Bridge: St Paul’s adds to £175m project’s troubled waters

Garden Bridge

St Paul’s adds to £175m project’s troubled waters
Stuff your own Christmas mouse ornament: An evening class in taxidermy with a festive feel

Stuff your own Christmas mouse ornament

An evening class in taxidermy with a festive feel
Joint Enterprise: The legal doctrine which critics say has caused hundreds of miscarriages of justice

Joint Enterprise

The legal doctrine which critics say has caused hundreds of miscarriages of justice
Freud and Eros: Love, Lust and Longing at the Freud Museum: Objects of Desire

Freud and Eros

Love, Lust and Longing at the Freud Museum
France's Front National and the fear of a ‘gay lobby’ around Marine Le Pen

Front National fear of ‘gay lobby’

Marine Le Pen appoints Sébastien Chenu as cultural adviser
'Enhanced interrogation techniques?' When language is distorted to hide state crimes

Robert Fisk on the CIA 'torture report'

Once again language is distorted in order to hide US state wrongdoing
Radio 1’s new chart host must placate the Swifties and Azaleans

Radio 1 to mediate between the Swifties and Azaleans

New chart host Clara Amfo must placate pop's fan armies
Homeless Veterans appeal: 'It's life, and not the Forces, that gets you'

Homeless Veterans appeal: 'It's life, and not the Forces, that gets you'

The head of Veterans Aid on how his charity is changing perceptions of ex-servicemen and women in need