Australia's climate policies are "a decade behind" other rich nations, according to a United Nations investment official, leaving the country exposed to risks of a so-called "green paradox" when carbon emissions will have to make a precipitous retreat.

A phasing out of coal and other fossil fuels is the centrepiece of four recommended investor goals to be unveiled by the UN's Principles for Responsible Investment unit in New York on Thursday morning, eastern Australian time.

The sun must set for coal, but what happens before the carbon curtain falls?

Fiona Reynolds, UNPRI's managing director, said investors needed to take the lead in forcing companies to reveal their exposure to fossil fuels and to step up pressure on governments to meet their Paris climate commitments.

"Investors have a huge, huge role to play on climate change," Ms Reynolds told Fairfax Media, citing their ability to influence the companies they own, including steering them away from fossil fuels to renewable energy. "This a really urgent issue."