All seven proposed expansions put to the NSW Labor government since it came to power in 2023 have been approved.
A further 19 are under assessment, despite a recent landmark court ruling finding the planning commission failed to consider the climate impacts of the state's largest coal mine expansion in 2022.
The project's approval was overturned in July by the NSW Court of Appeal after a community environment group successfully argued its case.
Elaine Johnson - one of the lawyers who led the appeal - says the NSW government has yet to take action in response to the findings.
"Which is surprising, because the impact is very clear," she told AAP.
Following the decision, Johnson Legal advised the state's planning department it needed to introduce local climate impact assessments as part of its approvals process for future projects.
The assessments would evaluate the impact of the mining projects on surrounding communities, including harms to infrastructure, rising cost of housing, and inability to obtain insurance in climate-affected regions.
These impacts were previously deemed unrelated to coal mine expansions under NSW planning laws, but the NSW Court of Appeal ruled in its July decision that they should be made mandatory considerations.
Months on, Ms Johnson said she had been advised the government was still considering whether to introduce the climate impact assessments.
It comes amid fears a bipartisan bill before parliament that would rewrite planning laws could make it easier for fossil fuel projects to be green-lit.
The legislation was touted by Labor as an initiative to accelerate housing approvals.
But environmental groups and lawyers argue the changes are not limited to housing development and could allow ministers to declare greenhouse gas emissions and climate change impacts are not relevant in the assessment of coal-mine expansions.
Parliament will vote in coming weeks on the proposed planning reforms and a bid by crossbencher Jeremy Buckingham to tack on a clause that ensures climate change cannot be considered irrelevant in planning decisions.
"Allowing climate change to be declared irrelevant would directly overturn the Mount Pleasant mine Court of Appeal precedent on considering downstream emissions," he told parliament in October.
"The (court's) decision is one of the most significant judgements on climate in the history of NSW, and it must be respected."
Labor is yet to refer a coal expansion project to the Independent Planning Commission, the authority responsible for making decisions on large development projects.
The Mount Pleasant expansion wrongly approved by the commission was referred there under coalition rule.
In response to questions from AAP, a NSW Department of Planning spokeswoman said the Independent Planning Commission remains the consent authority for major coal projects.
The department would ensure assessment processes satisfied all relevant legal obligations, including any recent Court of Appeal decisions, she said.
The most recent report published by the NSW Greenhouse Gas Emissions Projections predicts the state will fall short of legislated emissions targets if policy and action are not improved.
The targets - including 70 per cent by 2035 and net zero by 2050 - were passed by Labor in 2023.
The International Energy Agency says new fossil fuel project developments could lock in emissions that push the world above the 1.5C Paris Agreement temperature goal.
17°C