The judgement on the A5 road project handed down by Mr Justice McAlinden in the High Court on Monday has to represent some form of watershed moment for politics at Stormont.

The key part of the ruling was the Judge pointing to the failure of the Department for Infrastructure to provide evidence that the A5 project would not undermine interim and net zero greenhouse gas (GHG) targets set out in the 2022 Climate Change Act.

Perhaps the evidence can be presented at a later date, but anyone who takes time to look in detail at the current Act will quickly realise that some very creative accounting would need to be done to ensure a major road project was compatible with GHG targets.

In fact, the scale of the changes facing wider NI society is highlighted in previous advice from the UK Climate Change Committee (CCC). That advice includes a complete switch to electric cars and vans by 2032, a rapid shift away from oil fired central heating, cuts of around 20% to livestock numbers by 2030 and a major roll out of tree planting in NI. There would also have to be billions spent on carbon capture and storage technology. How the GHG emissions associated with a new road could dovetail with all of that is impossible to envisage.

Yet our politicians had the option of a less exacting (but still, extremely challenging) target suggested by the CCC of an 82% emissions cut by 2050. That advice was ignored by the majority, despite the warnings from the CCC and also from farmers who had worked out what net zero actually means for them. Months and months of lobbying fell on deaf ears.

The A5 judgement is perhaps the start of a process whereby wider society is made aware of the implications of the 2022 Act.

It was poorly drafted legislation that was allowed to get through Stormont because too many of our politicians would prefer to be populist than follow science, take good advice and make tough decisions that might not please their entire voter base. It will have to be revisited by MLAs.