Commonwealth Bank chairman Paul O’Malley says governments, businesses, unions and communities need to start planning to ensure a fair transition for parts of the country that depend on the coal industry.

The banking giant is seeking to start discussion about the major economic changes coming as Australia cuts fossil fuel use, and has estimated that about 800,000 people are living in regions with a “high dependency on the coal mining value chain”.

As AGL Energy announced the early closure of its Victorian coal-fired power station Loy Yang A on Thursday, O’Malley and CBA chief executive Matt Comyn underlined the need to support regions that are economically at risk from such moves.

O’Malley said the bank wanted to be transparent about the financial risks facing these communities, and by extension, the bank’s lending portfolio. CBA has said it has about $14 billion in mortgages in communities economically reliant on coal.

As banks face pressure from investors to cut their exposure to climate risks, Comyn said there was a need for a “socially just transition”, which would involve a plan to support coal-reliant regions.

O’Malley, a former chief executive of BlueScope, highlighted the risk of employers cutting capacity in some areas, and said it was necessary that Australia’s decarbonisation push occur in a “caring” way.

“Ultimately, the most important thing is that a lot of the transition in Australia will result in customers having to make a transition,” O’Malley said.

“We’ve got to make sure that our customers who are spread across Australia understand the need for change, and are supported through change.”

O’Malley said the official plan from the Australian Energy Market Operator (AEMO) suggested coal-fired electricity would be “materially” cut by 2030, with potentially some coal power stations operating until 2043, before adding: “But when you get the announcements that are coming out, I suspect it’s earlier rather than later.”