The first test of a project backed to spray millions of tonnes of chalk into the stratosphere, in an attempt to ‘dim the sun’ and cool the Earth, could happen in June.
Harvard University experts will test the system by sending a large balloon 12 miles above the Swedish town of Kiruna and have it drop 2kg of chalk dust into the stratosphere.
The aim of the estimated $3 million mission, backed by billionaire Bill Gates, is to have the chalk deflect a portion of the sun’s radiation, stop it from hitting the surface, and cool the planet.
The idea has been heavily criticised since its inception, with project director Frank Keutsch even calling the need for this scale of geo-engineering ‘terrifying’.
And experts have warned that the unusual technique could be disastrous for weather systems in ways nobody can predict.
Backed by a range of private donors including Gates, the test mission is launching from Sweden as they could offer a launch by the end of this summer.
The test would use a high-altitude scientific balloon (pictured) to raise around 2kg of calcium carbonate dust — the size of a bag of flour — into the atmosphere 12 miles above the surface
The balloon (similar to the example pictured) would take 600kg of equipment up into the stratosphere, and if all goes to plan, the dust would be released
The test balloon will lift 600kg of scientific equipment 12 miles above the surface of the Arctic town and if it all goes well, about 2kg of dust will be released.
This will then create a dust plume several kilometres in length – not large enough to have any effect on the intensity of the sun’s rays hitting the Earth.
During that first test the team would gather information on how particles of dust react with the air.
The aim of the mission, backed by billionaire Bill Gates, is to have the chalk deflect a portion of the sun’s radiation, stop it from hitting the surface, and cool the planet
This could then be fed into computer models to determine what would happen if it were ever carried out at scale.
Keutsch told the Times he wants to determine the true effects, as current models ‘may be too optimistic’ and make the technique look attractive.
It would takes tonnes of dust and plumes many hundreds of kilometres to make a difference – the theory being that the dust would create a massive sunshade.
There are a number of geo-engineering theories being proposed, including ‘shinier crops and buildings to reflect more sunlight’, microbubbles in the ocean and removing cirrus clouds.
This would reflect some of the sun’s rays and heat back into space, dimming those that get through and so protecting Earth from the ravages of climate warming.
Keutsch, whose Harvard lab is leading the project, says the strategy would only be deployed in desperation to stop parts of the planet becoming uninhabitable.
Without any efforts to stop climate change, such as curbs on greenhouse gas emissions from fossil fuels and other pollutants, parts of the world will be up to 10 degrees Fahrenheit warmer than they are today, studies show.