Can the thirst for black gold be made at any price? The extraction of the colossal reservations of bitumeux sands in the north of Alberta (Canada) makes the object of deep protests on behalf of scientists and of environmentalists. Last there dates, a report of the American Council of defence of natural resources (NRDC) gets worried about the threat of these careers of roofless oil to birds. Not less than one hundred and sixty million animals could disappear in the boreal forest in quarantine years. Because it is a nurserie true for migrant birds.

These sands contain huge reservations of oil, estimated at 173 thousand million barrels (1), the seconds of the world after Arabia Séoudite, according to the Canadian Association of the oil producers. A mixture of sand, of loam, of almost solid oil (10 - 12 %) and of a little water. When it makes the soil flush, the mixture is extracted in tracto-shovel. These roofless deposits represent 20 % Canadian reservations. The buried deposits request particular techniques of boring, making soften the bitumen to be able to exploit it. Today, the Canadian deposits produce a million barrels a day, a figure which should quadruple before 2020. The concerned surface is big as the quarter of the French territory.

The extraction of the bitumen requests big quantities of water and energy. The treatment consists in getting of the steam under pressure which creates a mixture of water and of oil which is then separated. Heat is given by power stations with gas, but it is more and more question to instal nuclear power stations devoted to the production of heat, to bring down the costs of extraction of the oil. Every barrel extracted from Alberta issues, before being used, eighty kilogramme of carbon dioxide, three times more than the conventional oil. This extraction already represents 4 % of greenhouse gas emissions Canada.

The Canadian boreal forest receives more half every spring of the American birds. A migration which concerns from 1 to three thousand millions fowls which leave their winter districts in the United States to come to nest in this region rich in lakes, in rivers and in marsh. According to NRDC, they count up to five hundred couples of birds by square kilometre. But this habitat is degraded by the working of the bitumen. Besides, oil industry pumps already so much water as consumption of a city of three million inhabitants. What changes the aquatic zones (rivers, marsh) visited by migrant birds. Besides, the rejected water contains a crowd of pollutants (benzene, xylène, mercury, etc.) . According to NRDC, 86 % boreal forests of Alberta would be already more undamaged. The organisation notices that some populations of birds have already diminished from 30 % to 90 % between 1968 and 2006, a tendency which will not be able to be reversed if the new plans of farms are not left.

Canadian oil industry maintains that she takes seriously very the environmental impact of her activity. And explain that she works to reduce the impact of these deposits on environment and climate. And underline that Alberta's oil will allow to improve the energy security of Canada. Of supply surer to the detriment of environment and of climate. What seems to leave cold the Canadian prime minister, named in a good standing on the site of the Canadian Association of the producers of oil: «I think that the working of bituminous sands will continue growing in accordance with the will of the government to reduce greenhouse gas emissions. We are of the opinion that these two objectives are not incompatible.»

(1) A barrel represents 159 litres of oil. Worldwide consumption is 80 million barrels a day, that is 29 thousand million barrels a year.

Picture: Working of bitumeux sands © Canadian Association of the producers of oil