Shipping emits a much greater share of greenhouse-gas emissions than you might think — more than a million tons annually, nearly 3% of the global total, and rising steadily. The problem is soluble — but work to solve it has been outrageously slow. Any further delay is unacceptable. A strong international push joined by governments, banks, businesses, ports and the shipping industry itself is needed right now to clean up the sector.

Why has so little been done? One big reason is that the more than 50,000 ships that carry freight internationally, hauling 90% of the world’s cargo and emitting as much carbon dioxide as Germany, operate largely beyond the scope of any country’s emissions limits. The United Nations’ International Maritime Organization, the world’s shipping regulator, sets goals, but progress requires action by national governments. Many have close ties with the shipping business and would prefer to avoid strict new rules. This needs to change. Ports and businesses also need to take action, collectively and individually.

In 2018 the IMO set a target of reducing greenhouse gases from shipping at least 50% by 2050. And starting this year, ships are required to scrub most of the sulfur out of their emissions, or use cleaner-burning fuels. These moves were much too timid. If the world is to avoid warming beyond 1.5 degrees Celsius, the goal must be much more ambitious. Over the next few years, the IMO is expected to dial up its goals for decarbonization. This work needs to accelerate, with governments following through promptly.

Another strategy has been to use lower-carbon natural gas, though this has led to higher emissions of methane, which is especially bad for the climate. Instead, shipping needs to switch to advanced biofuels and zero-carbon fuels such as hydrogen and ammonia, now being developed.

Ships made of lighter materials with slender hulls, air-lubrication technology, advanced propellers and other innovative features use significantly less fuel — especially compared with the oldest bulk carriers and tankers, which are only minimally streamlined. New wind technologies are in the works, including designs for both soft and rigid sails, wingsailstowing kitesrotating cylinders and wind turbines — some combined with solar cells and paired with batteries. It’s essential to get started right away replacing old ships with more efficient. Ships typically last 20 to 30 years, so it will take time to overturn the entire global fleet.

Governments can help by recognizing their responsibility to regulate ships traveling from port to port within their borders. This traffic accounts for 30% of all shipping emissions, according to the IMO. The commitments that countries made under the Paris climate agreement demand that they regulate these emissions. They can and should do so with low-carbon fuel standards, speed limits, investments in advanced shipping technology and other efforts.

The European Parliament is considering including shipping emissions in the EU carbon market starting next year, which would require shippers to pay for the carbon pollution they produce. This is a good idea that Europe should embrace — and a good model for other countries and the IMO alike.

Banks and other businesses can play a crucial role, as well. Some banks already incorporate emissions targets in their financing of new ships, and disclose the carbon intensity of their shipping portfolios. Companies whose goods and materials travel by water can express their preference for cleaner ships by signing contracts now to send freight on the first zero-emissions vessels. Ports can help lower emissions by reducing ships’ waiting time, supplying clean electricity so they can turn off their engines while docked, extending discount prices and other incentives for energy efficiency, and preparing the storage tanks and other infrastructure that will be needed to supply low- and zero-emissions fuel.