History has largely forgotten that the former Liberal leader, whose detailed policy manifesto Fightback! was dubbed the "longest suicide note" in Australian political history when he lost the "unloseable" election to Keating's Labor in 1993, was championing the cause of climate change all the way back then.

Former Liberal leader turned climate change activist John Hewson. Credit:Peter Braig

"I had a very significant climate policy back in '93 which I'm sure nobody read because they were distracted by something called the GST. I called for 20 per cent cut in emissions by year 2000 on a 1990 base. Here we are still debating 5 per cent by 2020. I think the country's lost the best part of 30 years in terms of making the essential urgent response. From a business point of view that's 30 years of lost opportunity."

Since then, climate change policy has brought about the downfall of three leaders, including Turnbull's first tilt at the Liberal leadership, when it was wielded to great political effect in the hands of former prime minister and famous climate sceptic Tony Abbott.

Dr Hewson, these days a businessman and renewable energy advocate, said he had been surprised by the lack of focus on climate change in this federal campaign, given the resurgence the issue is experiencing among voters, and urged bipartisanship to tackle the problem.