Yasmine Marrero | Churning up trouble: shipping and the climate crisis
In today’s hyper-connected world, we can order goods from across the globe with a single click, and our economies are more intertwined through global trade than ever before.
When we think about the environmental impact of global trade, production, consumption, and waste often take centre stage. But what about transportation, especially the shipping industry, which drives global commerce and is one of the slowest sectors to decarbonize?
Shipping is the backbone of our globalized society, a highly complex system ensuring our fuel, food, consumer goods, raw materials, and medicine reach their destinations. This convenience, however, comes at a high cost in greenhouse gas emissions. The shipping industry accounts for more annual carbon dioxide emissions than the entire nation of Germany, and these emissions are projected to rise unless we rapidly decarbonize.
TRADING CLIMATE FOR A BUCK
Up to 90 per cent of global trade is made possible by ships, and the vast majority of the shipping industry’s emissions are at sea, too. Maritime shipping not only harms marine environments with oil spills, litter, and more, but also pollutes our air.
Most vessels rely on especially polluting fossil fuels that harm our health by emitting sulphur dioxide, nitrogen oxides, and particulate matter, and significantly contribute to global warming.
About 60 per cent of shipping relies on heavy fuel oil (HFO), a fossil fuel that produces more emissions and emits more harmful chemicals, including carcinogenic PAHs, than most others. HFO is the most popular fuel in shipping because it’s 30 per cent cheaper than its alternatives, including diesel. However, because it’s so emissions-intensive, it’s wreaking havoc on our climate.
Greenhouse gas emissions from maritime shipping – mainly carbon dioxide and nitrogen oxides – significantly contribute to global warming. As they accumulate in the atmosphere, they intensify the effects of climate change, including prolonged droughts, extreme flooding, and increasingly frequent and severe tropical storms. Ironically, these climate-driven events are beginning to disrupt the shipping industry itself, altering sea levels, damaging ports and ships, and making traditional shipping lanes more hazardous and unreliable.
For example, the Panama Canal is one of the world’s most vital waterways for global trade, but it is getting increasingly risky for ships to pass through. Why? In 2023, a severe drought forced authorities to reduce daily crossings because there wasn’t enough water in the canal for large ships to navigate, causing supply chain backups. To squeeze through, some ships are even forced to decrease the amount of cargo they carry.
As the impacts of climate change intensify, governments and companies must incorporate climate adaptation to future-proof the industry. Routes will need to be redrawn, and industry leaders and policymakers must prioritize investing in climate-resilient maritime infrastructure. Fortifying ports, upgrading vessels, and planning for more volatile weather are no longer optional – they’re essential to maintaining global trade’s stability.
Climate change will affect everyone, including the industries driving it. By 2050, the shipping industry could lose an astonishing $10 billion a year from climate change’s effects on ports alone, and up to $25 billion annually by 2100. What on Earth, if anything, can we do to avoid this?
SOLUTIONS JUST IN REACH
One common suggestion is to turn to international diplomacy. International frameworks are key to guiding global coordinated action, and the International Maritime Organization (IMO) is an essential player. As the UN agency responsible for maritime transport, it sets climate goals and regulations for the shipping industry. In 2023, the International Maritime Organization (IMO) established a new goal to effectively eliminate the shipping industry’s greenhouse gas emissions by 2050, with interim goals of reducing emissions by at least 20 per cent by 2030 and 70 per cent by 2040.
However, this agreement isn’t binding, and, according to delegates in the negotiation room, representatives of countries with considerable economic interests in maritime trade and oil production held back their ambitions. As a result, the IMO failed to adopt effective emissions reduction measures and serves mainly as a guide for companies and governments to set their own goals.
Slow steaming is a temporary solution that could be implemented almost immediately. This is just a speed limit for ships, but it is often considered the most cost-effective way to reduce carbon emissions. In a real-world trial, ships emitted up to nearly 30 per cent less carbon just by sailing slightly slower; if ships reduce their speeds by even just a mile an hour, they could still reduce their emissions by 20 per cent.
By creating queues at ports, ships won’t need to race to load and unload cargo. Speed limits can be enforced globally using the Automatic Identification System, which tracks speed and is mandatory on all large ships. Regulation is possible and legally enforceable without significant administrative costs, and the industry has already started to slow steam to adapt to port backlogs.
SAILING INTO THE FUTURE
As pressure mounts to decarbonize, some companies are adopting renewable energy innovations. One promising innovation is a modern rendition of centuries of sailing: wind-assisted propulsion. Cargill’s Pyxis Ocean uses two giant foldable wings to capture the wind, decreasing fuel consumption by up to 30 per cent. Meanwhile, Airseas developed the Seawing, a massive kite that tows its ships and could cut fuel consumption by up to 40 per cent.
Fully solar- or battery-powered transoceanic ships aren’t practical because of energy generation and storage limitations. However, solar panels could power smaller ships or be combined with other power sources, like wind, to decarbonize larger vessels. Electric batteries can be used for regional transport. For example, in 2024, COSCO Shipping launched the world’s largest river-to-sea electric container ship in China, which uses no fossil fuels.
These few trailblazing vessels are a tiny fraction of the 60,000 cargo ships that need to decarbonize worldwide, and may be much more expensive than the industry-standard HFO. However, the innovations mark a critical transition phase in maritime transport. With the right policies and public pressure, we could be at the cusp of a revolution that brings the world’s biggest vessels closer to net zero.
HELP TURN THE TIDE
We don’t need to wait for the industry to propel itself into the age of sustainability: we can use our collective power as a force for good. Buy locally to support your community while decoupling from unsustainable shipping. Better yet, reduce your consumption to only what you truly need and want to move away from hyperconsumerism and its environmental harm, including the impacts of unsustainable shipping.
You can advocate for sincere plans to decarbonise at the local, national, and international levels, join environmental events in your area, sign petitions, and more!
At its core, the environmentalist movement has always been powered by grassroots activism, and we have a place for you. The planet needs us now more than ever, but there’s hope on the horizon if you join us in the fight.
Yasmine Marrero is writing and research intern at EARTHDAY.ORG. She is a government major at Dartmouth College studying international relations, law, politics, and business. Send feedback to columns@gleanerjm.com



