Apparently some time in 2010, the world’s inventory of cars - the vast majority oil-fuelled - reached 1 billion.
A back of envelope calculation tells me that if these were all swapped for electric vehicles like the Renault Fluence, powered from grid average sources, the tonnage of CO2 savings would be equivalent to the entire annual carbon footprint of UK and Spain combined, i.e. 855 million tonnes.
Anyone out there know how quickly we managed the horse-car changeover a century ago? Could we do the less radical transformation from oil to electricity, in less time?