Green group Transport & Environment (T&E) is claiming some shipowners will slip through the net of the European Union's emissions trading scheme (ETS) due to loopholes.

The group blamed "arbitrary exemptions" for some vessel classes, meaning that millions of tonnes of CO2 will not be covered by the carbon-pricing scheme from 2023.

T&E said this undermines the integrity of the EU's shipping laws.

The group calculates that more than 25.8m tonnes of CO2 emissions — close to the total output of Denmark at 26.2m tonnes — are exempt.

Offshore vessels servicing oil and gas facilities will not be included, and nor will dredgers, tugs and yachts.

Last July, the European Commission proposed an ETS for shipping, but it only applies to ships above 5,000 gt.

There are also exemptions for fishing and military vessels.

T&E said the exclusion of offshore ships makes no sense as they emit more carbon on average than bulkers or tankers.

Half of ships excluded?

All in all, the group claims just over half of Europe's ships are exempt from the proposal, despite them accounting for nearly 20% of the EU's shipping emissions.

This is double what the commission originally claimed exemptions would cover, T&E said.

Jacob Armstrong, sustainable shipping officer at T&E, said: "It's good that the EU is finally trying to address shipping's appalling climate impact.

"But its proposal based on arbitrary loopholes lets too many heavily polluting vessels off the hook. The EU must rethink its shipping laws to ensure that millions of tonnes of CO2 don't go unregulated."

T&E figures show emissions totalling more than 4m tonnes of CO2 will go unregulated from offshore ships of above 5,000 gt. Another 1m tonnes from dredgers will be exempted.

The group says the commission has explained the loopholes by saying they reduce the administrative burden while still covering the vast majority of emissions.

A new approach

"However, an approach that covers only ships that pollute over a certain amount — rather than based on size — would regulate more emissions without putting an administrative burden on small businesses," T&E added.

The group is recommending all vessels of above 4,000 gt be included, but only if they produce more than 1,000 tonnes of CO2 per year.

This would cover 12% more emissions than the current proposal.

The EU's shipping industry emits nearly 130m tonnes of CO2 each year, T&E calculates.

The European Commission has been contacted for comment.