SCIENTISTS, backed by billionaire Bill Gates, want to spray millions of tonnes of chalk into the stratosphere to reflect sunlight and slow global warming. Harvard University experts will test the system by sending a large balloon 12 miles above a Swedish town to drop 2kg of chalk dust into the stratosphere.

How crazy does this sound. Why don’t we just stop polluting the planet and allow it to recover from centuries of abuse by man, instead of sending more material up into our precious atmosphere? Easier said than done, but this sounds like a disaster waiting to happen.