Labor has to take the initiative in defending Australia against the dangers of climate change because the summer of catastrophe has highlighted our national vulnerability and because business and the states are now demanding national leadership, according to Anthony Albanese.

As revealed by Guardian Australia, the Labor leader will use a speech to a progressive thinktank on Friday to commit the ALP to adopting a net-zero target by 2050 if it wins the next federal election, without the use of carryover credits from the Kyoto period.

While Scott Morrison is holding off from making a commitment to carbon neutrality by 2050, partly because of an internal brawl within the Coalition and partly because the prime minister says Australia should not sign up to targets in the absence of costings, Albanese will say on Friday that adopting net-zero “should be as non-controversial in Australia as it is in most nations”.

According to the Labor leader’s speech notes circulated in advance, Albanese will commit Labor to adopting “a real target, with none of the absurd nonsense of so-called carryover credits that the prime minister has cooked up to give the impression he’s doing something when he isn’t”.

“That’s not acting. It’s cheating, and Australian’s aren’t cheaters. A Labor government will never use Kyoto carryover credits.”

Albanese will point out – as some in the government have noted publicly in recent weeks – that Australia accepted the net-zero pathway when the Coalition signed and ratified the Paris agreement. “This is what the world agreed to in Paris – Australia included.”

On Friday the finance minister, Mathias Cormann, confirmed the government “will be finalising a longer-term target in time for COP26” – the next round of climate talks in Glasgow in November.

“But what we will do as part of our process is to ensure that the agenda we determine to achieve any such target is environmentally effective and economically responsible,” he said.

Cormann accused Labor of committing to targets without setting out the cost, warning that Albanese is “making the same mistake” as former leader Bill Shorten.

Earlier, Labor’s climate change spokesman, Mark Butler, told Radio National the opposition would set out a detailed policy about how to achieve targets and its cost “well before” the next election.

Butler argued that the cost of reducing emissions should not be divorced from the cost of inaction and noted Melbourne University research had found actions to reduce emissions have a benefit cost ratio of 20 to one.

He also noted the CSIRO had found a net zero emissions path “will deliver higher wages and lower energy bills” in modelling relied on by the New South Wales Berejiklian government when it set its target of zero emissions by 2050.

In his speech, Albanese will say that “whether the current [federal] government accepts it or not, this goal is fast becoming the reality”.

“All states and territories in Australia have already promised to operate in a carbon-neutral way by 2050.

“The Business Council of Australia is calling for it. AGL, Santos, BHP, Amcor, BP, Wesfarmers, Telstra and others all agree. Seventy-three countries, including the UK, Canada, France and Germany, many with conservative governments, have already adopted it as their goal. Australia should too.”

Albanese will argue the lesson of the summer is preparation can help avert further tragedy, “and only positive, forward-thinking leadership can steer us through”. Courtesy of bushfires that claimed 33 lives and destroyed 3,000 homes, caused more than 1m animal deaths and saw more than 12m hectares burned, Australians have learned “we’re now living in dangerous times”.

Albanese will say climate change was a factor in the bushfires, and people touched by the tragedies of the summer now understood Australia had a lot to lose. “But the good news is we also have a lot to gain.”

The Labor leader will argue taking action on climate change means “more jobs, lower emissions and lower energy prices”.

“We should be a clean-energy superpower, harnessing the wind and sun to spark a new manufacturing boom and power generations of jobs; developing a hydrogen industry; creating manufacturing jobs here in Australia in new industries that provide well-paid jobs.

“Instead we have the government talking nonsense that they themselves have dismissed previously.”

The shadow cabinet took the decision to lock in behind a net-zero target before parliament resumed for 2020. The decision – Labor’s first significant move on climate policy post-election – comes as the opposition battles internal tensions about abatement targets and the future of coal.

Guardian Australia revealed on Thursday that concerns were expressed during the shadow cabinet deliberation about the risks of setting a concrete target in the absence of a roadmap to get there. There were also concerns about how Labor would answer the inevitable questions about the cost of action.

Labor has not yet taken a decision about what its interim emissions reduction target will be, and that decision looms as a future flashpoint.

The Morrison government will blast Labor for committing to a target without a cost-benefit calculation. But on Thursday, Labor’s Senate leader, Penny Wong, told the ABC the Coalition was not being transparent about the costs of inaction.

She said the path set by the Coalition was “a path which will impose, and is imposing, greater costs on Australians than the path of taking action”.

“We saw [the costs] over these recent months. We’ve seen them in the tragedies we’ve seen. We’ve seen them in the costs of drought and bushfires and natural disasters.

“But there’s more than the human cost. There is an economic cost, and what we know from what many people have told us is that it will cost us far more not to act than to act.”