We greet the new year with a new development on an old old story — the European Commission's Mobile Air Conditioning Directive.

Just before Christmas, the EC announced it would definitely be taking Germany to court for infringing the MAC Directive. Whether this represents the final chapter in the saga remains to be seen, but Germany is being called to account for effectively allowing car manufacturer Daimler to sidestep the requirements of European law for an astonishing three full years.

It is a decision that has been welcomed by refrigerant firms and carmakers alike, because it finally appears appropriate punishments will be brought for Daimler's decision not to switch from R134a to the lower GWP gas R1234yf, as required by the MAC Directive way back in 2013 (and this was after all carmakers were given an extra year's grace).

"The Commission alleges that Germany has infringed EU law by allowing the car manufacturer Daimler AG to place automobile vehicles on the EU market that were not in conformity with the MAC Directive, and failing to take remedial action," the EC announced.

"In referring Germany to the Court of Justice, the Commission aims to ensure that the climate objectives of the MAC Directive are fulfilled and that EU law is uniformly applied throughout the EU so as to ensure fair competitive conditions for all economic operators."

It is the EC's belief that a) German authorities should have ordered Daimler to recall the vehicles that were still using R134a in breach of the Directive; and b) it should have penalized the carmaker for trying to circumvent the Directive.

The decision has united the cooling industry and the car industry, because Daimler's rebellion has affected both camps in different ways:

• arguably slowing development of the HFO R1234yf by creating uncertainty
• definitely creating additional environmental impact by not converting to the lower-GWP refrigerant
• incontrovertibly gaining Daimler a competitive advantage because R134a is considerably cheaper to install than R1234yf

And, as I have written before, the outcome of the court case is also of real interest to environmentalists and legal practitioners alike. The MAC Directive is a flagship piece of EC environmental law, which, if it has no "teeth," makes nonsense of drawing up legislation to drive environmental change.

To briefly recap — it has been rumbling for a long while after all — the Court of Justice of the EU will hear the Commission's charge that Germany has failed to apply the MAC Directive by allowing Daimler, best known as owner of the Mercedes brand, to continue with R134a. These "infringement proceedings" can result in fines levied against Germany for every day the country failed to apply the law.

It is expected that Germany will argue Daimler had bona fide reason to refuse to use the new R1234yf — the only refrigerant currently endorsed by the carmakers' body the SAE, to have a GWP under 150, as required by the Directive — in that it had safety concerns.

However, these "safety concerns" surrounding the potential of the HFO to ignite in a head-on collision were dismissed as a negligible risk by the SAE; by the Commission's own independent science arm, the Joint Research Centre; and by Germany's Transport Authority, the KBA. This will no doubt be a key part of the Commission's case.

It was also surely no coincidence the decision to prosecute came in the same week as the Paris global climate talks — it is being viewed an indication that the EC will not allow resistance to its climate legislation.

In some environmental lobbying circles, the Daimler concerns are still cited as a valid issue today, but I feel I should restate the SAE's conclusion, which seems pretty unequivocal to me. The report from the SAE's Co-operative Research Group concluded:

"During numerous and frequent meetings, the CRP members determined that the refrigerant release testing by Daimler was unrealistic in that it created extreme conditions that favored ignition while ignoring many factors that would be present in a real-world collision."

The irony of all this is that Daimler has now announced it will start using R1234yf in limited circumstances — albeit with additional safety precautions installed — as an interim measure while it develops carbon dioxide air conditioning solution for installation in models from later this year.

Since Daimler's argument flew in the face of so much scientific opinion, I will happily continue alleging that the carmaker has brazenly flouted European law. What is galling is that as long ago as January 2014, the Commission was indicating it would take Germany to court, and it could yet take another six months to hear the case. One should not expect swift punishment for transgression in the European Union, which does nothing for confidence in the rule of law.

I would love it if someone were to estimate the additional carbon emitted in the three-plus years that Daimler models were using R134a when they could have used something much lower in GWP. I am sure all those who have been doing sterling work in reducing leakage in their stationary refrigeration systems over the past three years would be equally interested in hearing how their good work has been offset.

For this reason, I hope the Court of Justice throws the book at Germany