A think tank is launching a commercial urging NSW parliament to "stand-up to the coal lobby", as the government tries to pass laws prohibiting planning authorities from considering overseas emissions when examining local mining projects.

Deputy Premier John Barilaro in October revealed the state government was introducing legislation to prevent the regulation of overseas, or scope-three, greenhouse gas emissions in mining approvals.

But the Australia Institute, in a media release on Wednesday, said it “would be a dangerous step of political interference”.

“In an age of accelerating climate change it is unconscionable for the government to rush laws in that actually wind back protections against greenhouse pollution,” executive director Ben Oquist said.

“Buckling to the coal industry like this sets a terrible democratic precedent.”

The left-leaning think tank will on Wednesday launch the television commercial, which calls for NSW parliamentarians to “protect the laws that protect us”.

It comes after 47 scientists and experts signed an open letter to the state government in October urging it to defend the Independent Planning Commission against what it called “unwarranted and misleading attacks”.

It said NSW was already feeling the serious impacts of climate change, which were “made worse by emissions from coal mined in NSW”.

Mr Barilaro argues the proposed legislation and changes to the state environmental planning policy will “clarify concerns” around the export of coal.

It follows the planning commission in August imposing overseas emissions conditions on its approval of the United Wambo coal project near Singleton.

The commission in 2017 rejected the nearby Rocky Hill project with a judge subsequently stating the coalmine would increase global greenhouse gas emissions at a time when a “rapid and deep decrease” was required.

“These changes will help restore NSW law and policy to the situation that existed prior to the Rocky Hill decision and will provide the mining sector with greater certainty,” Mr Barilaro said in an October statement.