Extreme E: Lewis Hamilton helping make racing environmentally friendly

Lewis Hamilton isn't just the world's most successful Formula One driver ever, he's also a key backer of a new off-road electric vehicle racing series called Extreme E.

The plan is that super-powered electric cars will race in some of the most remote locations on earth in an effort to – the organisers say – promote sustainability and encourage the take-up of electric vehicles.

Our chief environment correspondent Justin Rowlatt has been sizing up the new series.