Hacking the planet’s climate could buy the world time to develop cleaner sources of energy to counter global warming, one of Britain’s most senior scientists has claimed.
Lord Rees, the Astronomer Royal, claims that launching mirrors into space, triggering algal blooms in the oceans and seeding clouds are just some of “Plan B” schemes which will have to be considered by world leaders unless carbon emissions can be cut in the next 20 years.
He is due to tell the British Scientist Festival in Newcastle that although it is an “utter political nightmare” because “not all nations would want to adjust the thermostat the same way “, hacking the planet through geoengineering will have to be discussed, the Guardian reported.
Lord Rees is set to say that he is pessimistic that global carbon dioxide emissions can be reduced to safe levels within the next 20 years, meaning that by the end of the century gas concentrations in the atmosphere will rise above 500 parts per million (ppm).
This could trigger a 6C rise in average temperature and the melting of the ice caps which in turn could accelerate climate change, it is believed.
“If the effect is strong, and the world consequently seems on a rapidly warming trajectory into dangerous territory, there may be a pressure for ‘panic measures’,” he will say.
“These would have to involve a ‘Plan B’ – being fatalistic about continuing dependence on fossil fuels, but combating its effects by some form of geoengineering.”
Plan B could including putting mirrors in space to reflect sunlight away from the Earth, encouraging the growth of carbon dioxide consuming algae by fertilising the oceans with iron, and seeding clouds in the upper layer of the Earth’s atmosphere to bounce some of the sun’s energy back into the stratosphere.
But alongside the political issues there could be unintended side effects to the plans, Lord Rees warns, and if the measures were ever halted climate change could return with a vengeance.
Furthermore, geoengineering will only buy time and will not provide a get-out for cutting emissions, he says.
He believes that the world’s power could be decarbonised in 50 years, but only if we start now.
Doug Parr, Greenpeace’s chief scientist, argued that there are too many downsides to the idea when there are safer steps which can be taken immediately.