ACT Peak Oil

Canada's abandonment of its progressive stance on the environment has grave implications for the whole planet, not just Canada (Canada courts big oil, GW, 22 June). As NASA climate scientist James Hansen has famously said, should the proposed XL Keystone pipe-line go ahead, it would be "game over" for the climate.

An estimated 170 billion barrels of oil are recoverable from these tar sands alone. That is a problem in itself in terms of greenhouse emissions from burning the oil once produced. As Michael T. Klare notes in his recent book The Race for What's Left, however, the extraction process itself burns up tremendous amounts of energy and carries multiple environmental risks. The most common form of production comes from open-pit mining which requires cutting down vast forests of virgin pine and spruce. The tailings ponds that now cover 50 square miles are hazardous to wildlife - 'in April 2009, some 500 migrating birds perished after alighting on one of these ponds', writes Klare.

Where the tar sands are too far below the surface, wells are dug, steam injected and the resulting liquefied bitumen pumped to the surface. This not only uses vast amounts of water but also natural gas to heat the water to make the steam. Carbon dioxide emissions from burning a barrel of oil made from tar sands are three times greater than burning a barrel of conventional oil. In addition, levelling the boreal forests for open cut mining destroys the forests' capacity to act as a greenhouse gas sink.

Who will then regulate the oil industry if not national governments? As conventional oil supplies start their inexorable decline, oil companies are rushing in to mine unconventional deposits of oil. As well as tar sands, these include deep- and ultra-deep water, Arctic, shale oil and heavy oil. All carry massive environmental risks. Who will clean up after an Arctic oil spill, for instance? How is it even done?

Jenny Goldie, Michelago NSW Australia