THE NEWS that delegates attending climate talks in South Africa yesterday were to discuss various artificial techniques that could reduce the amount of energy reaching the Earth from the sun is a worrying sign of the times.
As discussions appear to have yielded little progress to date at the United Nations climate talks in Durban last week in terms of reducing greenhouse gas emissions into the atmosphere, coming up with a Plan B to stop global temperatures rising is well worth looking into.
A geoengineering report released on Thursday evening produced by Britain’s Royal Society, the Washington-based Environmental Defense Fund, and the Academy of Sciences for the Developing World in Italy, is providing the basis for the discussions.
The scientists and philosophers from 122 countries who compiled the study came together last March for three days to brainstorm on how we can cool the Earth, in response to international concerns that world leaders would be unable to agree a new deal once the Kyoto Protocol comes to an end this year.
“The slow progress of international climate negotiations has led to increased concerns that sufficient cuts in greenhouse gas emissions may not be achieved in time to avoid unacceptable levels of climate change,” the report said.
Without a new climate change deal the notion that countries would reduce emissions and keep temperatures from rising above the two-degree threshold needed to avoid irreversible weather changes is fanciful at best.
However, scientists say that, in theory, if we can reflect even a small amount of the sunlight that hits the Earth’s surface back into space, it would have a dramatically positive effect in cooling the planet.
The ideas contained in the study by the coalition, which calls itself the Solar Radiation Management Governance Initiative, may seem far-fetched, but if they work, scientists believe global temperatures would be returned to levels of 250 years ago within a few years.
One idea put forward by scientists to reflect the sun away from the Earth’s surface is to spray aerosols containing sulphur dioxide high into the stratosphere. Here the sulphur would form into particles that would circulate the planet on stratospheric winds and block out a small amount of inbound sunlight.
Other suggestions include brightening marine stratus clouds to reflect sunlight back into the atmosphere; creating “sun shades” that can be positioned over the Earth; and even painting the world’s roofs white and planting light-coloured crops.
But are these ideas really feasible?
Steven Hamburg, chief scientist for the Environmental Defence Fund and co-chairman of the initiative, certainly believes so.
“Solar radiation management might sound, at first, like something from science fiction – but it’s not. There are already serious discussions beginning about it, and that’s why we felt it was urgent to create this governance initiative.
“Solar radiation management could be a Plan B to address climate change, but first we must figure out how to research it safely. Only then should we even consider any other steps,” he said in a statement.
While the scientists say their ideas are possible, if they become a reality the fallout is fraught with danger, as no one knows what their side-effects would be.
They could be physical in nature, in the sense that weather patterns and rainfall could unintentionally be altered, which means years of study are required to calculate the environmental impacts.
Or they could be political – spurring conflict among nations unable to agree on how such intervention, or geoengineering, will be controlled.
The idea of solar radiation management “has the potential to be either very useful or very harmful”, said the study.
