"Sunshade" to fight climate change costed at US$5bil a year

OSLO/SINGAPORE: Planes or airships could carry sun-dimming materials high into the atmosphere for an affordable price tag of below US$5 billion a year as a way to slow climate change, a study indicated on Friday.

Guns, rockets or a pipeline into the stratosphere would be more expensive but generally far cheaper than policies to cut world greenhouse gas emissions, estimated to cost between $200 billion and $2 trillion a year by 2030.