This first step of tar sand extraction is estimated to result in gasoline that carries a burden of "at least five times more carbon dioxide" then would conventional "sweet crude" oil production
Although producers recycle much of their water, about one barrel of water is lost for every barrel of oil culled
required to restore oil sand mining sites to at least the equivalent of their previous biological productivity, which involves revegetation and drainage restoration. None of this has yet been done on a large scale, however.
being accused of abandoning its "green sheen" by investing nearly 1.5bn to extract oil from the Canadian wilderness using methods which environmentalists say are part of the "biggest global warming crime" in history.
"oil sands" that lie beneath the Canadian province of Alberta and form the world's second-largest proven oil reserves after Saudi Arabia.
Producing crude oil from the tar sands a heavy mixture of bitumen, water, sand and clay found beneath more than 54,000 square miles of prime forest in northern Alberta an area the size of England and Wales combined generates up to four times more carbon dioxide, the principal global warming gas, than conventional drilling.
100 million tonnes of CO2 (equivalent to a fifth of the UK's entire annual emissions) a year by 2012
targets under the Kyoto treaty, according to environmentalist activists.
millions of tonnes of plant life and top soil is scooped away in vast open-pit mines and millions of litres of water are diverted from rivers up to five barrels of water are needed to produce a single barrel of crude and the process requires huge amounts of natural gas
Anglo-Dutch Shell and American combine Exxon-Mobil, boasts that it takes two tonnes of the raw sands to produce a single barrel of oil. BP insists it will use a less damaging extraction method, but it accepts that its investment will increase its carbon footprint
"It takes about 29kg of CO2 to produce a barrel of oil conventionally. That figure can be as much 125kg for tar sands oil. It also has the potential to kill off or damage the vast forest wilderness, greater than the size of England and Wales, which forms part of the world's biggest carbon sinks
The companies will invest $5.5bn (2.7) in the project, making BP one of the biggest players in tar sands extraction.
Canada claims that it has 175 billion barrels of recoverable oil in Alberta, making the province second only to Saudi Arabia in proved oil riches and sparking a 50bn "oil rush"
Canadian province expects to be pumping five million barrels of crude a day by 2030.
BP said it will be using a technology that pumps steam heated by natural gas into vertical wells to liquefy the solidified oil sands and pump it to the surface in a way that is less damaging than open cast mining. But campaigners said this method requires 1,000 cubic feet of gas to produce one barrel of unrefined bitumen the same required to heat an average British home for 5.5 days.
Licenses have been issued by the Albertan government to extract 350 million cubic metres of water from the Athabasca River every year. But the water used in the extraction process, say campaigners, is so contaminated that it cannot be returned to the eco-system and must instead be stored in vast "tailings ponds" that cover up to 20 square miles and there is evidence of increased rates of cancer and multiple sclerosis in down-river communities.
Experts say a pledge to restore all open cast tar sand mines to their previous pristine condition has proved sadly lacking. David Schindler, professor of ecology at the University of Alberta, said: "Right now the big pressure is to get that money out of the ground, not to reclaim the landscape. I wouldn't be surprised if you could see these pits from a satellite 1,000 years from now."
all Canadians are affected by the tar sands, no matter where they live.
all Canadians are affected by the tar sands, no matter where they live.
Canadians are affected by the tar sands, no matter where they live.
all Canadians are affected by the tar sands, no matter where they live.
The tar sands are the fastest growing source of global warming pollution in Canada. Yet, the federal government has no plan to curb their emissions
Global warming isn't the only environmental problem made worse by the tar sands. Toxic waste ponds, air and water pollution, habitat and species destruction are all legacies of the enormous operations in northern Alberta.
There are ways to curb the damage being done by the tar sands. Yet the federal government has so far failed to get industry to clean up.
Because of their sheer scale, all Canadians are affected by the tar sands, no matter where they live.