Former Australian Prime Minister John Howard has nothing but contempt for the "alarmist" scientific reports on global warming and climate change in a speech before an audience of climate change sceptics in London, England.

Mr Howard compared those who are urging governments to take action against climate change to religious zealots. He said he remained unconvinced that a global warming catastrophe is right around the corner and claimed he was "agnostic" on climate science. The former Australian leader preferred to rely on his instinct rather than on "exaggerated" reports, containing predictions of doom ahead.

He told British climate sceptics that an international agreement on climate change seemed unlikely. Mr Howard referred to a book written by one prominent climate sceptic that the scientific community has attacked for its false and misleading claims.

Mr Howard urged politicians not to be forced to surrender their role in the development of economic policy. He believes nuclear power is a clean energy source. Along with shale oil and fracking, nuclear power can meet the world's energy demands.

Mr Howard spoke before the audience of the Global Warming Policy Foundation, an organisation created by one of the UK's known climate change sceptic, Nigel Lawson. Mr Lawson also served as a chancellor in the Thatcher government.

Mr Howard revealed that Mr Lawson's book, An Appeal to Reason: a Cool Look at Global Warming, was the only book he read about the topic. He said he read the book published in 2008 twice while he was writing his autobiography and when he used it to support his arguments against climate change.

Mr Howard referred to Mr Lawson's claims in the book and said they were "compelling." Mr Lawson claimed that unmitigated warning might be 8.4 times better off for future generations in comparison with 9.4 times richer without climate change.

London School of Economics Grantham Research Institute on Climate Change Policy Director Bob Ward said the calculation that Mr Howard was referring to was actually based on "sleight of hand and faulty logic." Mr Ward said the book disregarded the scientific evidence and estimates presented by the Intergovernmental Panel on Climate Change.

Mr Howard's speech bore the title "One religion is enough" in reference to his claim that those who clamour for action against climate change employ a sanctimonious tone when reporting climate science findings.

He also criticised the "alarmists" for reportedly exploiting the NSW bushfires in October.