Tar sands in pictures

1) Boreal forest | The tar sand deposits sit beneath Canada’s pristine boreal forest, the world’s largest terrestrial carbon store. In 2007, 1,500 scientists from more than 50 countries called upon the Canadian government to provide more protection for what has been described as "a life support system for the planet".

Image: Jiri Rezac/WWF-UK

2) Wetlands | These are globally important habitats, home to rare species and vital for many migratory birds, and are also being destroyed by extensive tar sand developments.

Image: Jiri Rezac/WWF-UK

3) Seismic exploration lines | Tar sands cover 140,000 sq km in the primary boreal forest of Canada, an area larger than England. Before it is even decided whether an area will be exploited for tar sands or not, pristine wilderness is being destroyed and vital carbon storage and habitat lost. Seismic lines are cleared through the forest to assess possible tar sand reserves – in places these lines are six metres wide and just 40 metres apart. The cleared squares indicate where test drilling has taken place.

Image: Jiri Rezac/WWF-UK

4) Before and after – forest clearing | Once target tar sand reserves have been identified, vast areas of forest are cleared, the top soil and peat is removed, and wetlands are drained. The stark contrast can be seen above.

Image: Jiri Rezac/WWF-UK

5) Tar sands extraction – method 1 | The most easily accessible reserves are extracted via open cast mining. This emits on average three times more carbon dioxide than conventional oil extraction, not including the emissions resulting from deforestation. For every barrel of oil produced in this way at least 2 tonnes of material is mined. Some of these open cast mines are large enough to be seen from space. The small yellow dots in this image are in fact huge dumper trucks…

Image: Jiri Rezac/WWF-UK

6) 400 tonne dumper trucks! The largest in the world and larger than most houses.

Image: Jiri Rezac/WWF-UK

7) Toxic waste | The material from the mines is washed with warm water to remove the oil. On average, 3 barrels of water are used to produce 1 barrel of oil. Sourced from local rivers, most of this water becomes too toxic to be returned and collects in massive tailings ponds.

Image: Jiri Rezac/WWF-UK

8) Toxic ponds | Tailings ponds are acutely toxic to all life that come into contact with them, in November 2008, 500 migrating birds landed on a tailings pond and died almost instantly. Furthermore, a recent report found that 11 million litres of toxic waste water is leaking from these tailings into the water table and local rivers everyday.

Image: digitaljournal.com

9) Tar sand extraction – method 2 | Deeper reserves of tar sands are exploited in-situ. This form of extraction emits even more carbon dioxide than open cast mining, and is just as devastating to wildlife due to sub-surface pollution and forest disturbance.

Image: Jiri Rezac/WWF-UK

10) Upgrading | The oil extracted from tar sands is of low quality and therefore needs upgrading before it can be refined into petroleum products. This is a very dirty and energy intensive process and adds to the local pollution and carbon dioxide emissions from tar sand operations.

Image: Jiri Rezac/WWF-UK