Your questions answered: geoengineering

The world’s slow progress in cutting carbon-dioxide emissions has led some to call for research into ways we might counteract the effects of man-made climate change. Such attempts to geoengineer our climate range include planting trees to absorb CO₂; pumping sulphate aerosols into the atmosphere; and building giant orbiting space mirrors to reflect heat back into space.

We put your questions on these proposals for geoengineering to a panel of experts:

What do you see as the pros and cons of the different geoengineering techniques that have been proposed?

Richard Darton: Geoengineering comes in two main flavours: a variety of schemes known as Carbon Dioxide Removal (CDR), in which the most prevalent greenhouse gas is taken out of the atmosphere into safe storage; and Solar Radiation Management (SRM), which reflects sunshine back into space, to avoid it heating the Earth’s surface.

Carbon Dioxide Removal (CDR)  would be needed at massive scale in order to have any effect and this would take many decades