Tony Abbott has urged Malcolm Turnbull to follow Donald Trump's lead and ditch the commitments made under the Paris climate agreements, signed by Mr Abbott himself when he was prime minister.

The former PM now says he never anticipated the climate change reduction targets he signed up would be binding.But he was immediately repudiated by one of his supporters - junior minister Angus Taylor - who said Australia would honour its international agreements.

Former prime minister Tony Abbott says Australia should withdraw from the Paris climate agreement. Credit:Alex Ellinghausen

Delivering the 2018 Bob Carter Commemorative Lecture in Melbourne, Mr Abbott said he had never thought reducing greenhouse gas emissions was worth doing, unless it could be done at a modest cost.

He said despite the rate of carbon in the atmosphere increasing from 300 to 400 parts per million there had been no "dramatic consequences" on the climate.