Efforts to reduce our carbon emissions are falling far short of what’s necessary to keep our temperature rise below 2 degrees centigrade. Is it time to seriously consider another option- using technology to cool the planet? Tom Heap and Helen Czerski explore the controversial field of geoengineering.

They're joined by Shaun Fitzgerald, Director of the Centre for Climate Repair at Cambridge University, Peter Brannen, author of The Story of CO2 is the Story of Everything and by Alex Davey, Deputy Director of Science at the Royal Botanic Gardens Edinburgh.

Producer: Alasdair Cross

Assistant Producer: Toby Field

Rare Earth is produced in association with the Open University