Spraying particles into Earth's atmosphere to try and cool a warming planet might sound like a good idea in theory, but it will only work if it's done properly – and even then, it could carry risks that might spill beyond our control, scientists caution.

According to a team led by aerosol scientist Miranda Hack of Columbia University in the US, there are real-world logistical, engineering, and political limitations that mean any stratospheric aerosol injections ( SAI ) intended to reduce global warming should be considered extremely carefully before any attempt is made.

"There are a range of things that might happen if you try to do this – and we're arguing that the range of possible outcomes is a lot wider than anybody has appreciated until now," says atmospheric chemist and aerosol

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