A British climate sceptic on Monday challenged the Australian Prime Minister Kevin Rudd about climate change, saying the government's proposed emissions trading scheme (ETS) was unnecessary.

Lord Christopher Monckton, who is on a 13-day lecture tour of Australia, claims climate change is not a problem for the planet and carbon dioxide emissions do not contribute significantly to global warming.

"The ETS which I understand your government is proposing to introduce is unnecessary," he said.

"It will simply be the largest tax increase in the history of Australia. All that will happen is that bankers and politicians will become even richer than they are."

The former adviser to British Prime Minister Margaret Thatcher said Rudd carried out "a 45-minute sustained personal attack" on him last November claiming he had no evidence on the effects of climate change.

Monckton said his evidence against climate change included the fact tropical cyclones in Australian are at a 40-year low, Greenland's ice cover is increasing 5cm a year and polar bear numbers are on the rise.

He claims world temperatures will rise by just half a degree (Celsius) by the end of the decade, compared with UN scientists' prediction of a 3.5 degree rise.