A spokesman for BP added: "These are resources that would have been developed anyway." Licenses have been issued by the Albertan government to extract 350 million cubic metres of water from the Athabasca River every year.
The booming oil sands industry will produce 100 million tonnes of CO2 (equivalent to a fifth of the UK's entire annual emissions) a year by 2012, ensuring that Canada will miss its emission targets under the Kyoto treaty, according to environmentalist activists.
The company had shied away from involvement oil sands, until recently regarded as economically unviable and environmentally unpleasant.
Lord Browne of Madingley, who was BP's chief executive until May, sold its remaining Canadian tar sands interests in 1999 and declared as recently as 2004 that there were "tons of opportunities" beyond the sector.
But as oil prices hover around the 0-per-barrel mark, Lord Browne's successor, Tony Hayward, announced that BP has entered a joint venture with Husky Energy, owned by the Hong Kong based billionaire Li Ka-Shing, to develop a tar sands facility which will be capable of producing 200,000 barrels of crude a day by 2020.
In return for a half share of Husky's Sunrise field in the Athabasca region of Alberta, the epicentre of the tar sands industry, BP has sold its partner a 50 per cent stake in its Toledo oil refinery in Ohio.BP insists it will use a less damaging extraction method, but it accepts that its investment will increase its carbon footprint.