The federal opposition is on the edge of open revolt over a bombshell climate report, with one frontbencher threatening to resign and a Nationals senator likening it to a biblical apocalyptic screed.

The National Climate Risk Assessment, released on Monday, laid out a catastrophic vision of Australia’s future if climate change runs unchecked, unpinning Labor’s plan to update its emissions reduction target.

But warnings of a concerning uptick in heat-related deaths and ballooning risks for coastal towns as sea levels rise were brushed off by opposition home affairs spokesman and future Liberal leadership aspirant Andrew Hastie.

The Western Australian MP told ABC radio he was prepared to quit the shadow frontbench or be sacked unless the Liberal Party abandons its 2050 net-zero greenhouse gas emissions target, which is being reviewed by energy spokesman Dan Tehan.

Hastie said he still supported Sussan Ley’s leadership, but his mission was to build “a stronger, more secure, more competitive Australia”.

“I’ve nailed my colours to the mast,” he said on Monday after the report was released.

The prominent conservative’s comments will further ratchet up pressure on Ley, who has consistently said she wants to let the post-election review process play out before any decision on net zero.

Nationals senator Matt Canavan, a long-time net zero critic, backed Hastie.

“I’ve been saying for a long time that net zero is not working for Australia or Australians,” the Queensland senator told ABC radio on Tuesday.

“Andrew, like many Australians, are waking up to the fact that the hype around net zero is not matching the reality.”

Canavan questioned the accuracy of the report, accusing its authors of spreading fear rather than conducting an objective scientific analysis of climate risks.

“It reads like the Book of Daniel, not a government report,” he said, referring to the Old Testament text that references the end times.

“I mean, I like government reports that are sober and reasonable, not dramatic.”

So-called moderate Liberal Tim Wilson, whose website promotes his role in implementing Australia’s first plan to reach net zero by 2050 as an assistant minister in the Morrison government, played down the need to reduce emissions.

“I don’t think people are stressed about us having emissions reduction,” he told Sky News.

“But we want to make sure that energy policy is driven by net-zero price increases and net-zero outages.”

At a crunch moment for climate policy, the report authors will be grilled about Australia’s vulnerabilities to weather hazards and the government’s plan to manage them by a Senate committee on Tuesday.

Prime Minister Anthony Albanese described the risk assessment as a wake-up call for anyone who denied the reality of climate change, as his government prepares to release its 2035 emissions target this week.

The cost of disaster recovery payments could rise by $40 billion a year as climate hazards compounded, the report warned.

It painted a sobering picture of Australia’s ecosystems, economy and way of life under global warming above pre-industrial levels.

Climate Change Minister Chris Bowen acknowledged many Australians would find the climate impacts “confronting” but said they were a vital reminder to keep cutting emissions.

Ley and her deputy Ted O’Brien have advocated for “credible” targets that don’t overburden households and businesses.

“We need to reduce emissions, but not at any cost,” they said in a joint statement.

A sharp increase in deaths due to heatwaves was among the most concerning findings of the climate risk assessment.

In addition, as many as 1.5 million people could be impacted by coastal extremes, such as flooding and cyclones, by 2050.

The vulnerabilities of coral reefs to higher ocean temperatures have been well-documented.

But broad-based ecosystem changes can also be expected, with about half of native plant species found in any location anticipated to be different at three degrees of warming.

-AAP