The Albanese government is being urged to end old growth logging “at a minimum” in order to meet a 2035 emissions reduction target recommended by the Climate Change Authority.

Australia’s most respected forest scientists, Prof David Lindenmayer, of the Australian National University, has also written to the authority questioning why it did not go further in its advice and recommend an end to all native forest logging.

The authority’s report, released last week, said ceasing old growth logging and halving re-clearing rates would be one of the steps required to meet even the lower end of a goal to cut emissions by 62% to 70% by 2035.

The report found that ending old growth logging, reducing other types of native forest harvesting and planting new forests “where it makes sense” could deliver about 6% of the necessary emissions reductions.

Last Friday, a day after the government announced it had accepted that target range, the environment minister, Murray Watt, told ABC radio in Tasmania – where logging of old growth forest continues – “it’s not the government’s intention to stop old growth logging altogether”.

The Greens forests spokesperson, the Tasmanian senator Nick McKim, said the authority’s advice was clear that “even Labor’s bottom-of-the-range target of 62%” could not be met unless old growth logging, at a minimum, ceased.

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“Labor needs to announce a date to end old growth logging, and if they’re not going to do that they need to explain where they are going to find the emissions reduction to make up the shortfall,” McKim said.

Some states, such as NSW, already have restrictions on logging identified and mapped old growth forest, which is forest that has either not been logged or cleared previously or where evidence of past disturbance is negligible. But logging of other high conservation value native forest continues.

The Greens position is that all native forest logging should end and it has called on the government to use forthcoming reforms to Australia’s environment laws to ban the practice.

McKim said ending native logging and reining in land-clearing would be one of the cheapest, fastest and most effective ways the government could cut emissions and protect biodiversity.

“You could end native forest logging literally in months and it would have a massive emissions benefit,” he said.

“It would actually save taxpayers money because it’s a heavily subsidised industry and what you’ve got to do is just transition communities.”

McKim pointed to some states where this was already happening, such as NSW, where the Minns government has announced a major economic transition package for workers and communities affected by a moratorium on logging within its planned great koala national park.

In a letter to the CCA’s chair, Matt Kean, this week, Lindenmayer wrote “the key issue here is the end [of] all native forest logging”. He wrote that scientific analysis showed “properly protecting native forests in Australia would make a highly significant contribution to the nation meeting its GHG (greenhouse gas) emissions reduction targets”.

In Tasmania alone, Lindenmayer wrote that native forest logging caused the equivalent of 1.1m cars worth of emissions every year.

“It’s blindingly obvious that we have to stop native forest logging altogether and it’s one of the most powerful short-term emissions reduction steps we can take,” he told Guardian Australia.

“There is also a massive economic benefit that would come from stopping native forest logging because the public wouldn’t have to support the massive subsidies that prop up the industry.”

A government spokesperson said McKim was “misinterpreting the CCA’s role”, which they said was to recommend a target to government, “not on plans to get there”.

They pointed back to remarks by the climate change and energy minister, Chris Bowen, to the ABC’s Insiders last Sunday, stating “there was one piece of advice the Climate Change Authority gave us”: the target of 62% to 70%.

“That’s the only recommendation before us, and we obviously decided to accept it,” Bowen said.

“So everything else the Climate Change Authority said doesn’t necessarily mean it’s your plan?” the host, David Speers, asked.

“Everything else – no. What they then did is in their report to me, quite rightly, is ran through some of the possibilities as to what achieving that might look like,” Bowen said.

In response to Lindenmayer’s concerns, the government spokesperson said the agriculture and land sector plan, one of six sector plans on Australia’s transition to net zero by 2050, “outlines support for a diverse landscape – balancing competing demands between carbon storage, nature repair and agriculture”.

A spokesperson for the Climate Change Authority said its analysis found “one way to achieve the 62% to 70% target involves ceasing clearing of old growth forests, halving re-clearing rates, and reducing native forest harvesting”.

“This is part of the Authority’s illustrative pathway for achieving the 62-70% target. There are other ways to achieve the same target, provided the equivalent level of abatement is made up across the economy,” it said.