Environment Minister Josh Frydenberg has pointedly reminded Tony Abbott that "climate change is real", and that it was the former prime minister's decision to sign Australia up to the Paris climate change deal.

Mr Frydenberg has been politically close to Mr Abbott throughout his career, including a stint as the former prime minister's parliamentary secretary. Like fellow cabinet ministers Peter Dutton and Mathias Cormann, he remained loyal to Mr Abbott until the end of his leadership but has since wholeheartedly backed Prime Minister Malcolm Turnbull.

Mr Abbott delivered a major speech in London on Monday in which he suggested the science of climate change was not settled and that Australia's decision to sign up to the Paris climate deal was "a compromise based on the advice that we could achieve it largely through efficiencies, without additional environmental imposts".

The former prime minister has also questioned the value of the Paris deal in recent months and suggested Australia's commitment to reduce its emissions by 26-28 per cent by 2030 against 2005 levels was only aspirational.