International shipping is the backbone of our global trading system. But it can no longer be given a free pass on climate change. If this industrial sector were a country, it would be the sixth-largest emitter of greenhouse gases in the world — and if it doesn’t act now to reduce those emissions, by 2050 they could surpass total anticipated European emissions.

The International Maritime Organization, which sets regulatory standards for international shipping, is set to meet in London next week to consider approaches to reducing these emissions. So far, progress by the I.M.O. has been agonizingly slow, and the group’s timetable — to develop an “initial strategy” next week and a plan by 2023 — is similarly dilatory.

If the I.M.O. does not take action quickly, there is no hope of keeping the global temperature increase below the tipping points set by the Paris climate agreement. This is only possible if emissions peak by 2020 and decline rapidly thereafter. Every industrial sector, as well as country, must play its part in reaching the goal. And international shipping is the last big sector regulated by the United Nations to act.

Unfortunately, some countries that advocate the merits of climate action elsewhere are not singing from the same song sheet at the I.M.O., where talks are already underway.

The good news is that this is actually an important economic opportunity for international shipping if it wants to remain the cheapest low-carbon option for our global supply chain. Certainty about emissions standards is necessary to encourage the right kind of investment now. As Alistair Marsh, the chief executive of Lloyd’s Register, which provides consulting services to the shipping industry, said recently, “The later we leave decarbonization, the more disruptive it will be for shipping.”

Fortunately, solutions exist. A 2009 study by the I.M.O. found that “a significant potential” for reducing emissions “through technical and operational measures has been identified.” Those measures, according to the study, “could increase efficiency and reduce the emissions rate by 25 percent to 75 percent below the current levels. Many of these measures appear to be cost-effective.” But impediments, including “costs, a lack of incentives and other barriers, prevent many of them from being adopted,” the report added.

The Marshall Islands first proposed an industrywide target to curb shipping’s rising emissions in the lead-up to the 2015 Paris climate conference. The Marshall Islands may be a tiny, climate-vulnerable nation of low-lying islands and atolls threatened by rising seas, but it also hosts the world’s second-largest shipping registry and is almost entirely reliant on sea transportation for food and other crucial supplies. Given all this, perhaps no country is better placed to highlight the need to act, and to do so in a way that is economically sustainable.

In Paris, the Marshall Islands went on to form a High Ambition Coalition of progressive countries that was pivotal to securing the final agreement. That coalition is mobilizing once again, with the Pacific Island nations, the Caribbean, Latin American countries, Europe and others already working together to ensure a similarly strong outcome next week. While the Marshall Islands may be one of the countries most at risk from climate change, no country will be safe.

With this in mind, nearly 50 countries have already joined the Tony de Brum Declaration, which has called for urgent action to reduce the shipping industry’s emissions. The declaration, sponsored by the Marshall Islands and President Emmanuel Macron of France at the One Planet Summit in Paris last December, is named in honor of our friend, the former foreign minister of the Marshall Islands and a champion of the Paris Agreement, who died last year.

Countries truly committed to climate action will not accept anything less than a strong deal next week. But despite efforts by the I.M.O.’s secretary general, Kitack Lim, tackling shipping emissions still remains far down in the political in-tray of too many countries.

We need to change that, and change it quickly. Delaying action until 2023, as some have suggested, is waiting too long. In 2016 the world agreed on a similar deal to regulate aviation emissions, as well as the Kigali Amendment to the Montreal Protocol, which will phase down planet-warming refrigerants. And recent initiatives to tackle coal and to boost electric vehicles are showing that the economy is shifting much faster to reducing greenhouse gas emissions than many thought possible.

To achieve the goals of the Paris Agreement and to avoid the most devastating impacts of climate change across the globe, we cannot forget about international shipping. The world needs to take notice.