Cyclone survivor Chris Black, 15, on Tuesday told National Australia Bank chief executive Ross McEwan to stop bankrolling the climate crisis by funding coal, oil and gas companies.

"I want to understand why you refuse to stop funding fossil fuels," he said, interrupting the AFR Banking Summit to hand the bank boss a letter.

"I think it's ridiculous."

NAB's Mr McEwan said he does understand the issues, and encouraged Mr Black to look at the bank's policies on coal, oil and gas.

"No, we're not funding new ones," the banker said.

Australia's big four banks - NAB, Commonwealth Bank, Westpac and ANZ - intend to phase out fossil fuel lending, and have clear commitments to financing a net zero emissions economy, but were warned at the summit to move more quickly.

Rebecca Mikula-Wright, CEO of the Investor Group on Climate Change, said the federal election has sent a clear signal from the community for more ambitious climate action this decade.

Obviously banks have an additional role in terms of how they lend, and pressure on them will to continue to increase, she said.

Australia has a competitive advantage in renewable energy that can be used to bring industry and manufacturing back onshore, instead of shipping raw materials offshore.

But Labor's 2030 target of 43 per cent emissions reduction must be implemented quickly, with detailed decarbonisation pathways, to send a clear signal to investors of the new direction, Ms Mikula-Wright said.

Rochel Hoffman, merger and acquisitions executive at Deloitte Australia, said clients are thinking deeply about climate in every deal and also see a huge opportunity to drive change.

She said private capital has been on the sidelines, but the tussle over energy giant AGL's future provides a clear example of how that is changing.

Tech billionaire Mike Cannon-Brookes has forced AGL to abandon plans to split into two parts and shut down its polluting power plants over a decades-long trajectory, which clears the way for another possible takeover bid and quicker exit from coal.

Anthony Miller, chief executive of Westpac Institutional Bank, acknowledged there's a lot more that has to be achieved in Australia, including how emissions are measured and reported, and how to measure performance against promises.

"Everyone is absolutely committed to what we need to do," he said.

"We need to electrify everything we do in the country, we then need to decarbonise the way power is produced for that, and that represents a major challenge in terms of the grid."

Significant investment is needed to turn the electricity grid into one powered by renewable energy, he said.

Julien Vincent, executive director of shareholder activist group Market Forces, said the election result was sparked by "immense frustration" on climate and the role of women.

"I think both of those have been addressed to a significant degree and hopefully neither of those issues get taken for granted again."

He said bank clients such as Whitehaven, Woodside, Santos, and New Hope should have their finance cut off.

"We need to stop making the problem worse," he said.

"These companies need to be told to sling their hook and come back when they're not trying to expand fossil fuels and have got a credible transition plan."

He said "people are rightly terrified" after deadly bushfires and Australia's costliest flood.

The 2022 event is estimated by the Insurance Council to have cost $3.35 billion in insured losses across Queensland and NSW.

Australian Associated Press