★ 0.0
★ 7.0
★ 7.2
★ 10.0
★ 6.9
★ 6.4
★ 7.1
★ 6.3
★ 6.6
★ 6.2
★ 8.0
★ 6.1
The huge tar sands in Alberta are a potentially profitable resource, but the environmental impact could be heavy and long-term.
