The UK is putting tens of millions of dollars into trials for the technique known as geoengineering - intervening in nature in an attempt to slow climate change.
The funding will support trials in marine cloud brightening and stratospheric aerosol injection, which aim to reflect sunlight or absorb carbon dioxide to cool the planet.
Officials say the move is out of concern that emission reduction efforts may not be enough to avert dangerous climate tipping points.
However, critics warn that geoengineering could have unpredictable side effects, potentially altering weather patterns and diverting attention from emissions cuts.
Kathryn speaks to Damian Carrington is The Guardian's environment editor.
