A giant mechanical digger gouges out a chunk of topsoil, grass and tree stumps, extending a neat furrow that stretches into the distance. Dozens of similar furrows run parallel with the regularity of a ploughed field.
Yet no crop could grow in the pitch-black surface exposed by the machine working 1,000ft below our helicopter. This is the edge of a fast-expanding open-cast mine in the Canadian tar sands, one of the world’s most polluting sources of oil.
It takes only a few minutes to fly across the 200 sq miles (520 sq km) of mines, processing plants and man-made lakes of toxic water. But Canada has so far extracted only 2 per cent of a resource that it hopes will turn it into a global energy superpower.
BP and Shell are among dozens of oil companies preparing to raise production from 1.3 million barrels a day at present to 2.5 million by 2015 and 6 million by 2030.
