Shipping containers and cranes April 6 at the Port of Newark, one of the largest ports in the United States, in Elizabeth, N.J. (Justin Lane/EPA-EFE)

Member nations of the United Nations body charged with regulating shipping on the high seas adopted a first-ever strategy Friday to blunt the sector’s large contribution to climate change — bringing another major constituency on board in the international quest to cap the planet’s warming well below an increase of 2 degrees Celsius (3.6 degrees Fahrenheit).

The strategy embraced by a committee of the International Maritime Organization would lower emissions from container ships, oil tankers, bulk carriers and other vessels by at least 50 percent by the year 2050 vs. where they stood in 2008. The group also said that emissions from shipping should reach a peak, and begin to decline, as soon as possible.

“IMO remains committed to reducing GHG emissions from international shipping and, as a matter of urgency, aims to phase them out as soon as possible in this century,” the group said.

But the United States “reserve[d]” its position on the strategy, with Coast Guard official Jeffrey Lantz, who headed the delegation to the London deliberations, saying that the country views “the establishment of an absolute reduction target as premature.”

The United States also objected to how responsibilities would be divided between developed and developing countries, and expressed “serious concern about how this document was developed and finalized.”

Shipping in recent years has been responsible for about 800 million tons annually of carbon dioxide emissions, according to Dan Rutherford, the marine and aviation program director of the International Council on Clean Transportation, who was in attendance for the deliberations in London this week. That means shipping’s emissions are 2.3 percent of the global total.

“If you counted it as a country, it would be the sixth-largest source of CO2 emissions,” said Rutherford, noting that 800 million tons of annual emissions is comparable to emissions from Germany.

And ships, by burning heavy fuel oil, create not only carbon dioxide emissions but also significant emissions of black carbon, or soot. Black carbon is a short-lived but powerful climate-change driver.

Moreover, if nothing is done to halt emissions growth in the industry, emissions are projected to continue to grow, and shipping would burn up a significant share of the remaining global carbon emissions allowable under the Paris climate agreement — releasing as much as 101 billion tons of carbon-dioxide-equivalent emissions between now and 2075, according to an analysis by Rutherford’s organization.


(International Council on Clean Transportation)

“The world’s shipping industry has now, for the first time, defined its commitment to tackle climate change, bringing it closer in-line with the Paris Agreement,” Tristan Smith, an expert on shipping and energy at the University College London energy institute, said in a statement.

Shipping and aviation are two major greenhouse-gas-producing sectors that have sat rather uncomfortably in the context of the global push to cut emissions under the Paris climate agreement.

Both sectors are very difficult to decarbonize, since they rely on energy-dense fuels to allow ships or planes to travel great distances without stopping.

Meanwhile, since the sectors have major international components, they are not the responsibility of any single country to regulate as part of a domestic climate-change strategy. Instead, addressing their role in climate change has fallen to United Nations bodies such as the IMO and the International Civil Aviation Organization.

Yet despite the ambition of the current strategy for shipping, Rutherford’s group’s analysis shows that it may not be strong enough. The group says that to be consistent with the Paris agreement, shipping should emit no more than 17 billion tons of carbon-dioxide-equivalent emissions from 2015 onward but that the current agreement implies emissions between 28 billion and 43 billion tons. (No action at all, meanwhile, could have meant 101 billion tons.)

Groups that were pushing for something stronger included small island nations, which have the most to lose if warming exceeds 1.5 degrees Celsius, or 2.7 degrees Fahrenheit, since sea-level rise for these countries could be devastating.

The Baltic and International Maritime Council, the world’s biggest shipping consortium, celebrated the agreement.

“IMO has done something no one has done before: set an absolute target for emission reductions for an entire industry. It is a landmark achievement in the effort to reduce emissions, and something that every other industry should look to for inspiration,” Lars Robert Pedersen, the group’s deputy secretary general, said in a statement.

For shipping to decarbonize, current fuel oils would have to be replaced by biofuels or, perhaps  ultimately, hydrogen or batteries. But such innovations so far are being tested only in smaller ships, rather than the largest vessels, Rutherford said.

“The largest container ships use a tremendous amount of energy. They’re going to be harder to electrify or put hydrogen in,” he said.

A large emphasis will also certainly be placed on more energy-efficient designs to maximize the work performed by current fuels.

The current document is referred to as an “initial strategy.” But from here, IMO is expected to move ahead with regulations for global shipping that will gradually require these carbon-saving changes to the industry. Those could include mandatory energy-efficiency requirements, speed limits or other measures.