Radical plan to combat global warming 'may raise temperatures'

A controversial proposal to create artificial white clouds over the ocean in order to reflect sunlight and counter global warming could make matters worse, scientists have warned.

The proposed scheme to create whiter clouds over the oceans by injecting salt spray into the air from a flotilla of sailing ships is one of the more serious proposals of researchers investigating the possibility of "geoengineering" the climate in order to combat global warming.

Geoengineering – deliberately altering the global climate – was dismissed as outlandish fantasy a decade ago but has recently been seen as a serious topic of study, given the international failure to curb global emissions of carbon dioxide and the possibility of extreme climate change.

However, a study into the effects of creating man-made clouds which reflect sunlight and heat back into space has found that the strategy could end up having the opposite effect by interfering with the natural processes that lead to the formation of reflective white clouds over the ocean.

A team of scientists from Britain and Finland found that spraying salt water into the air to encourage the formation of clouds may actually hinder natural cloud formation over the coastal regions of the continents because of other pollutants from industrial activities.

"Our research suggests that attempts to generate brighter clouds via sea spray geoengineering would at best have only a tiny effect and could actually cause some clouds to become less bright," said Professor Ken Carslaw of the University of Leeds.

White clouds form naturally over the ocean as a result of saltwater spray being blown high into the air. The salt crystals form tiny particles on which cloud droplets form and the denser the droplets, the whiter the cloud and the more reflective it is towards incoming sunlight.

Twenty years ago, scientists proposed that it might be possible to augment this process with a fleet of ships designed to spray saltwater into the air. Calculations suggested that this could cool the planet if carried out on a large enough scale.

However, a computer model used by Professor Carslaw and his colleagues suggested that it would be difficult to create a uniform layer of saltwater spray and that natural particles in the air, called aerosols, could interfere with the process. "The formation of clouds from artificial sea spray is particularly sensitive to background levels of aerosol. This means that injecting spray around coastal areas where there is a lot of air pollution from land may not produce enough extra cloud drops to stave off global warming," Professor Carslaw said.

"In some locations, the artificial spray particles may hinder natural drop formation and could have an opposite effect on climate to that intended. In practice, generating a uniform covering of reflective clouds over large regions of the world's oceans would be extremely challenging," he said.


Artificial clouds

This notion involves augmenting the natural process of white-cloud formation over the oceans to reduce levels of incoming sunlight and heat. But it would not help the increasing acidity of the seas because it fails to address rising levels of carbon dioxide in the atmosphere.

Artificial volcanoes

Another idea is to emit sulphate particles high into the atmosphere to reflect sunlight back into space. These would simulate what happens in a volcanic eruption when the aerosol particles from the eruption cut out sunlight and cause limited global cooling. The sulphates would wash out within a couple of years but again this "solution" does not address ocean acidity, or the potential acidity of the sulphate aerosols.

Artificial trees

Being able to emulate the way trees convert carbon dioxide gas into solid carbon-containing substances is seen as the best geoengineering idea. But nobody has been able to do it better than trees – so why not simply plant more forests? This proposal reduces carbon dioxide concentrations and so helps ocean acidity.

Mirrors in space

The idea is to create a huge reflective surface between earth and the sun that could be adjusted to interfere with incoming solar radiation. Apart from the immense technical difficulties, the political implications of who controls this technology are problematic to say the least.

peopleFrankie Boyle responds to referendum result in characteristically offensive style
Arts and Entertainment
Highs and lows of the cast's careers since 2004
New Articles
i100... with this review
ebooksAn unforgettable anthology of contemporary reportage
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating

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

iJobs Job Widget
iJobs General

Cover Supervisor

£75 - £90 per day + negotiable: Randstad Education Group: Are you a cover supe...

Marketing Manager - Leicestershire - £35,000

£30000 - £35000 per annum: Ashdown Group: Marketing Manager (CIM, B2B, MS Offi...

Marketing Executive (B2B and B2C) - Rugby, Warwickshire

£22000 - £25000 per annum: Ashdown Group: A highly successful organisation wit...

SEN Coordinator + Teacher (SENCO)

£1 per day: Randstad Education Leeds: Job Purpose To work closely with the he...

Day In a Page

Scottish referendum: The Yes vote was the love that dared speak its name, but it was not to be

Despite the result, this is the end of the status quo

Boyd Tonkin on the fall-out from the Scottish referendum
Manolo Blahnik: The high priest of heels talks flats, Englishness, and why he loves Mary Beard

Manolo Blahnik: Flats, Englishness, and Mary Beard

The shoe designer who has been dubbed 'the patron saint of the stiletto'
The Beatles biographer reveals exclusive original manuscripts of some of the best pop songs ever written

Scrambled eggs and LSD

Behind The Beatles' lyrics - thanks to Hunter Davis's original manuscript copies
'Normcore' fashion: Blending in is the new standing out in latest catwalk non-trend

'Normcore': Blending in is the new standing out

Just when fashion was in grave danger of running out of trends, it only went and invented the non-trend. Rebecca Gonsalves investigates
Dance’s new leading ladies fight back: How female vocalists are now writing their own hits

New leading ladies of dance fight back

How female vocalists are now writing their own hits
Mystery of the Ground Zero wedding photo

A shot in the dark

Mystery of the wedding photo from Ground Zero
His life, the universe and everything

His life, the universe and everything

New biography sheds light on comic genius of Douglas Adams
Save us from small screen superheroes

Save us from small screen superheroes

Shows like Agents of S.H.I.E.L.D are little more than marketing tools
Reach for the skies

Reach for the skies

From pools to football pitches, rooftop living is looking up
These are the 12 best hotel spas in the UK

12 best hotel spas in the UK

Some hotels go all out on facilities; others stand out for the sheer quality of treatments
These Iranian-controlled Shia militias used to specialise in killing American soldiers. Now they are fighting Isis, backed up by US airstrikes

Widespread fear of Isis is producing strange bedfellows

Iranian-controlled Shia militias that used to kill American soldiers are now fighting Isis, helped by US airstrikes
Topshop goes part Athena poster, part last spring Prada

Topshop goes part Athena poster, part last spring Prada

Shoppers don't come to Topshop for the unique
How to make a Lego masterpiece

How to make a Lego masterpiece

Toy breaks out of the nursery and heads for the gallery
Meet the ‘Endies’ – city dwellers who are too poor to have fun

Meet the ‘Endies’ – city dwellers who are too poor to have fun

Urbanites are cursed with an acronym pointing to Employed but No Disposable Income or Savings
Paisley’s decision to make peace with IRA enemies might remind the Arabs of Sadat

Ian Paisley’s decision to make peace with his IRA enemies

His Save Ulster from Sodomy campaign would surely have been supported by many a Sunni imam