For more than 40 years – ever since the Great Oil Crisis of 1973 – scientists, governments and media have been warning that the world must reduce its dependence on fuels derived from hydrocarbons. Initially, the main worry was supply – would the world run out of oil and gas before we found alternatives? But by the 1980s, an even greater danger came to the fore: climate change, aggravated by the massive amounts of CO2 being spewed into the atmosphere by oil-derived fuels.