Harvard researchers are set to test aerosol sprays that could be used to combat climate change.

The controversial technique could one day be used to block incoming solar radiation and cool down Earth to combat the effects of global warming. 

The first-of-its-kind experiment could begin as early as next year and will pump small amounts of material into the stratosphere to reflect the sun's rays.

But scientists have previously warned that the results of changing our own climate could be 'catastrophic'.

It will test the feasibility of what scientists are calling 'solar geoengineering' - though the Harvard team say that they will only use water vapour at first.