Speaking ahead of this week's ANU Crawford Leadership Forum in a pre-recorded speech, UN Secretary-General on Climate Action Selwin Hart said if the federal government continued a "business as usual" response to climate change, it would have dire ramifications on Australia's high living standards.

The summit also included an address by OECD secretary general and former Liberal senator Matthias Cormann, who warned big tech was fracturing the global taxation system and leaving nation sates penniless.

In his speech, Mr Hart said Australia had been a leader in future fiscal planning and cautioned that both sides of government should aim to ensure the country maintained its high development standards by capitalising on a decarbonised economy.

"We are at a critical juncture in the climate crisis," Mr Hart said. "If G20 countries, including Australia, choose business as usual, climate change will soon send Australia's high level living standards up in flames.

"By contrast, if countries including Australia, choose bold climate action, a new wave of prosperity, jobs fairness and sustained economic growth is there for the taking."

Mr Hart also noted bolder and ambitious 2030 targets were needed to ensure global warming was limited to less than 1.5 degrees.

It is understood bolder targets before the end of the decade will be a focus of the climate talks at the Glasgow climate change summit in October.

The UN warned Australia would need to phase out coal production by 2034 to be in line with other G20 nations.

Mr Hart said it would be the responsibility of governments to ensure fossil fuel workers were able to transition to renewable energy industries.

Mr Cormann, who addressed the same forum, used his position as head of the OECD to warn of the rising challenges from globalisation and the digital disruption.

The former Liberal finance minister said large multinational companies were flouting loopholes in the various taxation systems to avoid paying tax in countries where the profits were made.

"The current outdated rules have allowed too many large multinationals to earn significant income in market jurisdictions around the world without having to pay any or only very little corporate income tax there," Mr Cormann said. "Those inequities and distortions have to be addressed and ideally, they have to be addressed in a multilaterally agreed way."

Mr Cormann noted digitisation and globalisation had distorted the system and created a challenging environment for various governments to raise revenue for public services and infrastructure investment.

The OECD is also attempting to act as an intermediary for competition regulators around the world, in a bid to ensure global competition is an even playing field.