WA Premier Roger Cook is being criticised after walking back his government’s promise to legislate a net zero emissions by 2050 target.

“I’m not going to shackle Western Australia to legislation which damages our efforts to help the world to decarbonise and reduce emissions,” Mr Cook told reporters at a press conference on Wednesday.

The government’s own Climate Change Bill 2023 was introduced to parliament by former environment minister Reece Whitby in November 2023.

It aimed to enshrine into law a commitment to reach net zero emissions by 2050 and to set interim targets from 2035 onwards.

The bill, however, wasn’t debated after its introduction and ultimately lapsed when parliament was dissolved ahead of this year’s March election.

This leaves WA and the Northern Territory as the only jurisdictions without a legislated 2050 target.

“Unfortunately, what we’ve seen now is the government walk even further back saying that they may not introduce a bill at all,” says WA Greens leader Brad Pettitt.

“[They’re] walking away from targets despite themselves actually saying less than 18 months ago how important targets are in terms of driving climate action, driving investment, and also giving the community certainty that the government is doing all it can to actually address climate change.”

Dr Pettitt introduced the Greens’ own version of the government’s now former bill last week.

He says the Climate Action this Decade Bill 2025 includes a requirement for a 2030 target to be set in addition to the 2035, 2040, 2045, and 2050 targets the original bill contained.

“Otherwise, it’s actually the same bill because it was a bill that provided a good foundation for climate action,” he says.

Peter Newman, Professor of Sustainability at Curtin University, says the government’s net-zero walk back could jeopardise the state’s ability to attract investment from across the globe.

“[Renewable energy] is the fastest growing area of financial investment,” he says.

“It will continue to grow in importance for the world of finance because [investors] have to be able to show their own credentials in the net zero space.”

He has also stressed that national targets aren’t enough on their own, after the premier said WA was already captured by the federal net zero by 2050 legislation.

“To avoid doing a net zero legislation of our own is avoiding the things that state governments do, and federal governments don’t,” Professor Newman says.

“They need us as well because things to do with land, the energy system, with transport, these are managed by the state, not by the federal government.”

Dr Pettitt says the country can’t achieve net zero without WA reducing its own emissions, which have risen by more than eight percent since 2005.

“The idea that Western Australia’s emissions keep rising and somehow the country as a whole is meant to get to net zero does not make sense unless you had a huge amount of offsetting,” Dr Pettitt says.

“But Western Australia’s emissions are approaching 100 million tonnes a year and you can’t offset all of that.”