The International Maritime Organisation (IMO) is to introduce the first mandatory measures designed to cut greenhouse gas emissions from the world’s shipping fleet, but doubts remain over its potency and application.

In what is being hailed as an historic breakthrough for the maritime sector, members of the IMO meeting in London voted late last week to approve proposals requiring new ships to meet technical efficiency standards that are estimated to lower emissions by between 25 and 30 per cent by 2030, compared to a business-as-usual scenario.

The newly adopted Energy Efficiency Design Index (EEDI) regulations enter into force from the start of 2013 and will apply to all ships of 400 gross tonnage and above from 2015 onwards.

This date is significant as the EU had threatened to incorporate shipping into its emissions trading scheme from 2013 if the industry failed to take steps to curb its emissions. However, a spokesman for EU climate commissioner Connie Hedegaard admitted that the bloc may still try to pull international shipping into the emissions trading scheme if it decides the new standards do not go far enough.

For several years the EU has been calling on the shipping industry to address rising greenhouse gas emissions, which currently make up around three per cent of the global emissions and are expected to more than double by 2050 if no action is taken.

While the bloc welcomed the agreement as a “major achievement”, Hedegaard stressed that the IMO still needed to agree more demanding market-based measures to deal with rising emissions.

“I hope this momentum will help the ongoing debate on further reducing emissions from international maritime transport,” she said. “Europe remains fully committed to keep addressing this issue at all levels and international fora.”

The new agreement will force ships built between 2015 and 2019 to improve their efficiency by 10 per cent, while those built between 2020 and 2024 will have to improve efficiency by 20 per cent. Ships built post-2024 will have to meet standards requiring a 30 per cent improvement in carbon efficiency.

Peter Boyd, chief operating officer of campaign group Carbon War Room, said the move would save $5bn in fuel costs and over 20 million tons of CO2 each year by 2020. But he added that the IMO had missed a “bigger environmental and economic opportunity” by limiting the regulations to new ships.

“The real prize for the planet and profitability is in the existing fleet,” Boyd said. “Today’s new standards if applied to all ships, not just new builds, would save the industry more than 220 million tons of CO2 and $50bn a year. Chasing all profitable efficiency savings could save even more.”

Controversially, countries will be able to waive the regulations until 2019, after the IMO acceded to pleas from a group led by China, Brazil, Saudi Arabia and South Africa for more time to roll out new technologies.

An IMO spokeswoman admitted to BusinessGreen that it was possible a large number of countries could delay the regulations, but she questioned whether it would be in their interest to do so.

“These amendments were designed to save money and fuel, so if you are ordering a ship, where is the logic for not applying it?” she asked.

IMO secretary-general Efthimios E. Mitropoulos added in a statement that he hoped greater consensus on the measures would be achieved in the future, after five of the 65 delegates voted against the regulations and 12 abstained.

“Although not by consensus – which, of course, would be the ideal outcome – the Committee has now adopted amendments… introducing mandatory technical and operational measures for the energy efficiency of ships,” he said. “Let us hope that the work to follow on these issues will enable all Members to build the consensus that evaded the Committee this time.”