Australian retirement savings could be put at risk unless regulators force the financial sector to be more transparent in managing the investment risks created by climate change.

That is is the view of former Liberal leader John Hewson, who is calling for regulators to take a much tougher line on how the financial sector handles the risks associated with global warming.

Dr Hewson, chairman of the Asset Owners Disclosure Project, made the call as new rankings showed many of the world's 500 largest asset owners, including some of Australia's biggest superannuation funds, were taking a more active approach to protecting their portfolios from climate change risks.

Even so, the AODP's annual rankings still labelled many financial giants as "bystanders" in their response to climate risks, and Dr Hewson said mandatory disclosure of climate risks was needed to prevent an "Australian train wreck".

Because of the country's high carbon intensity at a time when vital trade partner China is also trying to shift towards renewable energy, he argued Australia was particularly exposed to "systemic financial risk" caused by climate change.

"With the Australian government missing in action, the RBA, APRA and ASIC must drive change in fund and company reporting. Failure to do so may cost us our retirement savings," Dr Hewson said.

The AODP, a not-for-profit body that produces the annual ranking, is part of a growing international push among investors and regulators for greater action to avoid the risks of a "carbon bubble".

Much of this activity is focused on greater disclosure, in the belief more information would allow markets to "price in" the risks created by climate change.

The survey by the AODP said there had been a 19 per cent increase in the number of pension funds, insurance companies and sovereign wealth funds that were taking action in response to climate change. Yet there were still 201 asset owners that were ignoring climate risk, and 187 judged "bystanders" - those taking only the first steps in acknowledging these risks.

Australian funds were ranked among global leaders, with the Local Government Super fund reclaiming the top position, First State Super in third place, and Australian Super ranked 18th.

For the first time, the survey also ranked the world's 50 largest asset management businesses.

The only Australian manager included in this list was Macquarie Group, which the AODP report gave a D or "bystander" rating on its management of climate change risks. The bank did not complete its survey.

Macquarie said it "rejects any suggestion it does not recognise the financial risks of climate change", pointing to its disclosure of carbon exposure, and its large investments in renewable energy.

"As a significant global asset manager, Macquarie is fully committed to ensuring environmental risks are identified and managed responsibly in our business activities and relationships, and each member of staff shares the responsibility for identifying and managing these risks as part of normal business practice," a Macquarie spokeswoman said.

"As one of the world's largest investors in renewable energy, having invested or arranged over $14 billion into renewable energy projects since 2010, Macquarie is particularly aware of the opportunities and responsibilities that will continue to accompany the transition to a low-carbon economy."

Macquarie was this month given the green light to buy the United Kingdom's Green Investment Bank in a $3.9 billion deal, despite some critics doubting the bank's commitment to carrying out the company's environment goals.

The AODP ranked asset owners and managers on the basis of their governance and strategy, portfolio risk management, and their metrics and targets.

The report comes after a committee including Coalition, Labor and Greens Senators last week recommended several policy changes to improve how financial risks of climate change are disclosed to investors.

The Senate inquiry, which reported on Friday, said the corporate watchdog should review its guidance to directors on climate risks, while the Australian Securities Exchange should provide guidance on when disclosure of climate risks was needed.

The inquiry also said the government should review the Corporations Act to consider whether financial reporting obligations should be changed to force companies to make a "holistic" consideration of the viability of their business model.

In February, Australian Prudential Regulation Authority executive board member Geoff Summerhayes??? also said it would keep a closer eye on how banks, insurance companies and asset managers responded to the financial risks of global warming.