Greenpeace activists scale BHP Billiton’s global headquarters in Melbourne to drop an "invoice" banner for its overdue pollution debts. Operating some of Australia’s most polluting coalmines, BHP Billiton is one of Australia’s top 10 polluting companies. In 2009 it produced close to 13 million tonnes of carbon pollution in Australia. With a modest carbon price of $26/tonne, BHP Billiton would be liable for just $338 million - equivalent to 0.6% of their global turnover.