The ruling in the Land and Environment Court against the project proposed by mining company Gloucester Resources has been hailed by environmental groups as a landmark decision in their fight against fossil fuels.

But Mr Johnsen said the decision by the court’s chief judge, Justice Brian Preston, “goes beyond the remit of what the court should be about”.

One of the major reasons for this was because Justice Preston included the “Scope 3” emissions – mostly the carbon dioxide emitted by the burning of the coal by Rocky Hill’s overseas customers. 

“The outcome is not surprising given that the department (of planning) had recommended against it but for the judge to make such a significant contribution with his comments around Australia’s climate change obligations to Paris is taking it to a whole new level,” Mr Johnsen said.

“It puts a lot of developments at risk. Agriculture, transport … so many parts of our community are at risk because of this judgement.

“The Upper Hunter has mines, wines, equines and bovines.

“All are as important as each other, all of them produce emissions, and so by the nature of this judgement, all of them are at risk.”

Mr Johnsen’s accusations of  “judicial activism” were criticised by upper house Independent Jeremy Buckingham, who has written to the court accusing the Nationals MP of contempt of court.

Mr Buckingham said yesterday that Mr Johnsen was trying to bring the court into disrepute but Mr Johnsen said he was entitled to his opinion “like any other citizen”.

The NSW Minerals Council was still examining the decision but chief executive Stephen Galilee said: “If the intention of the judgement is to make developments contribute to emissions reductions beyond Australia’s national targets, there will be dire consequences for a range of industries, including agriculture, manufacturing and transport, which are all major emitters”.

Mr Galilee said such an outcome would carry massive economic and household costs but have “almost no impact” on global emissions reductions.

 The Environmental Defenders Office, which was part of the case, says the coal industry could have put a “contrary view” to the court about climate change, but did not, indicating that it accepted the science about global warming. Chief executive David Morris agreed the decision could “affect industries across the board”.

 The Newcastle Herald was unable to contact Gloucester Resources but legal sources said any appeal  would be heard by a full bench of the NSW Supreme Court. 

Read the verdict here