Peter Hinchclife, secretary-general of the International Chamber of Shipping, agreed, adding: "We call upon the EU and China, and indeed all IMO member states, to support the industry proposals. The priority of governments should be to focus on the development of alternative, fossil-free fuels and the IMO should assess whether holding CO2 below 2008 can be achieved with technical and operational measures alone."

But, the two shipping organizations said they were worried about unilateral measures being considered by the EU that would include making shipping a part of the European Emission Trading Scheme. China is also considering a national emission trading scheme that could eventually include shipping.

The European Community Shipowners' Associations and the International Chamber of Shipping have said they broadly support the decision by China and the European Union to press ahead with plans to cut carbon dioxide emissions from ships, despite the United States announcing its withdrawal from the Paris climate agreement.

"The withdrawal of the United States from the Paris climate agreement should not jeopardize an ambitious global strategy to reduce the CO2 emissions of shipping," said Patrick Verhoeven, the shipowners' association's secretary-general. "We are therefore pleased that the EU and China appear to be working toward reinforced cooperation on delivering a climate agreement for shipping at the International Maritime Organization."

In Brussels last week, China and EU leaders agreed to intensify cooperation over a shipping deal, and will join Canada in hosting a ministerial summit in September to advance the Paris climate agreement, accelerating the transition to clean energy.

The shipowners' association and the shipping chamber are both working with the International Maritime Organization to produce an international proposal that will keep total global shipping's carbon dioxide emissions below the 2008 levels, before steadily cutting annual emissions to a percentage that is yet to be agreed by 2050.

"We remain firmly opposed to a patchwork of regional schemes that would distort international shipping markets, while doing little to tackle the reduction of the global industry's actual emissions," said Verhoeven.

Emission trading schemes allow companies that join them to trade greenhouse gas emissions allowances, provided the overall cap set by the administrators is not exceeded.