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.

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