At the United Nations conference on climate change in Montreal, the US delegation is opposing an initiative by Canada to start formal discussions on how to tackle global warming.

Meanwhile, the scientist who first raised the alarm about global warming has said if greenhouse gases continue to be produced at current levels, the planet will be irreparably damaged within a decade.

Speaking at a meeting of experts in San Francisco, Dr James Hansen warned that just one more degree of warming would take the Earth into climate patterns it had not experienced for more than 500,000 years.