Sir David Attenborough has said it is “palpable nonsense” to suggest that Australia’s bushfire crisis has nothing to do with climate changeas he warned “the moment of crisis” has arrived.

The 93-year-old British naturalist made the direct link between the ongoing bushfires and climate change during an interview with the BBC published on Thursday.

“As I speak, south-east Australia is on fire. Why? Because the temperatures of the Earth are increasing,” he said.

“We have been putting things off year after year. We’ve been raising targets, saying ‘oh well, if we do it in the next 20 years …’ the moment of crisis has come.”

More than 10.7m hectares of land have burnt so far in the Australian bushfires, including 80% of the Blue Mountains, and 50% of the Gondwana world heritage rainforests.

While Australian prime minister, Scott Morrison, has talked down suggestions there are climate change deniers in his party, several Australian government MPs have continued to downplay the role of global heating on the bushfire crisis, and Morrison has attempted to pivot the debate from acting on climate change to resilience and adaptation.

Attenborough said the world can no longer prevaricate and delay decisions, and the change needed to be made not by appealing to optimism but by highlighting it is a life or death decision.

“This is not just having nice little debates and arguments and then coming away with a compromise. This is an urgent problem that has to be solved,” Attenborough said.

“And what is more is that we know how to do it, that’s the paradoxical thing, that we are refusing to take steps that we know have to be taken.

“And every year that passes makes those steps more and more difficult to achieve.”

He said China needed to step forward and announce it is curbing carbon output because of climate change, and everyone else would “fall into line”.

“That would be the big change that one could hope would happen.”

He said the public mood had already shifted.

“People can see the problem, particularly young people can see the problem, and that must force governments to take action.”