Charting a greener course: How weather routing offers an easy path to decarbonizing the shipping sector

The shipping industry depends on well-worn maritime routes that have stood the test of time. Over the centuries, some of these routes have evolved to adapt to changes in technology, geography and geopolitics—but others are so deeply entrenched that they have carved metaphorical grooves in the ocean. As climate change continues to affect weather and ocean patterns, these traditional pathways are becoming both environmentally costly and economically inefficient.

IE University’s Dr. Daniel Precioso Garcelán, in close collaboration with a broader IE University team that includes project lead David Gómez-Ullate and Rafael Ballester-Ripoll, is working on an initiative that promises an immediate, cost-effective solution. By harnessing mathematical algorithms, the team is exploring how ships can leverage ocean currents, wind patterns and wave data to improve their routes—in much the same way drivers use Google Maps. This approach could present a timely solution to a pressing challenge. The shipping industry faces growing pressure to decarbonize and must take every opportunity to reduce its environmental impact.

The slow journey to net zero

“In recent years, the shipping sector has faced added pressure to reduce emissions,” says Dr. Precioso. “Alternative fuels such as green hydrogen, nitrogen and liquefied natural gas are being explored, and sail technology has been revived to harness the power of the wind.” Shipping accounts for 3% of global CO₂ emissions. If current trends continue, this figure could be as high as 10% by 2050.

The International Maritime Organization (IMO) has introduced some measures to address the sector’s contribution to climate change, though critics say their response has been slow and insufficient. In 2023, the organization released the IMO Strategy on Reduction of GHG Emissions from Ships. This document pushed for the uptake of zero or near-zero greenhouse gas (GHG) emission technologies, fuels and energy sources, aiming to achieve net zero by 2050. 

More recent developments include the adoption of the IMO Net-Zero Framework, which includes a mandatory fuel standard for ships and a global pricing mechanism for emissions. These measures will come into force in 2027, requiring ships to reduce their GHG emissions per unit of energy consumed. Vessels that exceed set emission limits will have to purchase credits to offset their excess, while those using sustainable technologies will be eligible for financial rewards.

Congested ports also increase emissions

Port congestion is another major international issue in the shipping industry. Since ships can’t always adequately predict when they will arrive at their destinations, they’re regularly met with packed docks and extended waitlists when they do.

The problem with this from an emissions perspective is that sitting beyond port, out in the ocean, is a diesel-heavy, carbon-intensive act. Ships burn fuel even when they’re stationary. What’s more, the scrubbers that many have installed, which are used to wash exhaust gases and prevent sulphur oxides from being released into the atmosphere, further pollute the water. When scrubber washwater is discharged into the sea, heavy metals are released with it, contaminating the water and contributing to ocean acidification. This led to the OSPAR Commission banning the release of discharge water from ships’ scrubbers in mid-2025. 

As a result of these and other related issues, addressing so-called “just-in-time” arrivals has become an industry priority.

The IE University research team’s proposed solution—weather routing—stands to be a critical piece of the puzzle. And best of all, it’s an intervention that can be put in place almost immediately. 

The Google Maps of the sea

Weather technology and prediction systems have been advancing steadily for decades, and predictions for ocean currents, waves and wind are more accurate today than they have ever been before. Dr. Precioso is capitalizing on this data to improve the way the shipping industry plans routes. 

Together with a large multidisciplinary team, he helped to develop an algorithm called Weather Navigation. It draws on oceanographic and meteorological data to optimize shipping routes in order to reduce fuel consumption and greenhouse gas (GHG) emissions.

“In principle, it works a bit like Google Maps: it finds the best routes for ships to follow,” explains Dr. Precioso. In practice, of course, it’s not quite so simple. The roads that Google Maps depends on, for example, are static. They aren’t subject to currents, swells, storms and waves. Google Maps is surface-level; Dr. Precioso’s solution is concerned with what’s happening both above and below the surface.

To gather a comprehensive picture of this shifting landscape, his solution pulls data from public repositories, including the National Oceanic and Atmospheric Administration; Copernicus, the European Union's Earth Observation Programme; and the HYCOM consortium, a multi-institutional effort sponsored by the National Ocean Partnership Program. With this information, it builds detailed models that can recommend an ideal route for a ship to take.

“With our solution, ships stand to reduce their fuel consumption and emissions by as much as 10% a year,” Dr. Precioso explains. “That amounts to approximately 300 tons of fuel, or the equivalent of taking 200 to 300 cars out of circulation per vessel, per year. For a shipping fleet of several thousand ships, the financial savings in fuel and the environmental savings in emissions are enormous.” 

What’s more, the algorithm is easy to install, and implementing this system is dramatically more cost-effective than many other sustainability initiatives. All it requires is a small computer on board with access to the internet or a simple USB connection. The infrastructure and training involved are relatively negligible. 

The European Parliament has recognized weather navigation as one of the best solutions for sustainability in general, not just in its sector. It is also receiving widespread attention at naval conferences in Spain and beyond. The IE University team is working closely with colleagues at the Universities of Cádiz and Cartagena in Spain and at Dalhousie University in Canada. A grant from the Fundación BBVA, a charitable foundation that promotes research, advanced training and knowledge dissemination, has made much of this research possible. 

The technology driving change

Sailors have long followed prevailing winds, so how is this different? What innovations have pushed weather routing to the fore once again? 

Improvements in long-term forecasting are the first contributing factor. Ships are often at sea for days or weeks at a time. In order for weather routing to be useful, the prediction systems need to be as long-term and reliable as possible. Developments in this field have been impressive. “We have more than tripled our reliability window for forecasts, and that allows us to develop better, more dependable routes that shipping companies and their captains can trust,” says Dr. Precioso. 

There have also been major developments in computation. In the past, the calculations required to evaluate the many factors involved (from a ship’s displacement, hull length, engine power and cruising speed, to weather changes and sea conditions) and deliver an accurate route recommendation took hours. Now, all this can be done in minutes, and can be continuously updated. “We have worked with exceptional computer scientists to create a pipeline of data that is constantly being downloaded and used to adjust the algorithm accordingly,” Dr. Precioso elaborates. "If circumstances change at all, the algorithm can deliver an alternative route almost immediately.”

Multidisciplinary approaches like this project are invaluable in the fight against climate change, and they speak to another contributing factor—one that is less technological and more human. As climate change mitigation strategies become more urgent and complex, they demand the skills of an ever-expanding network of people. This project would not have been possible without the expertise and commitment of a large team of data scientists, mathematicians, software developers, oceanographers, naval engineers and shipping industry experts.

The many parties involved in this project are a testament to the essential role of human relationships in the adoption of new technologies—a theme that will be explored in a future article in this series.

A combined approach

Like most other carbon mitigation strategies, weather optimization is not a solution on its own. In fact, it will likely work best if combined with the other emissions reduction initiatives the shipping industry is exploring. 

For now, weather routing assumes that ships are using fossil fuels. But even as the sector adopts alternative fuels, weather routing will remain relevant. “Alternative fuels are still fuels, and shipping companies will always want to reduce their use as much as possible, both for financial and environmental reasons,” Dr. Precioso adds. “Once we regulate fossil fuels properly, we’re going to have to regulate sustainable fuels. Anything that reduces this reliance is going to be beneficial.” 

Modern sail technology is similar. New sails such as WindWings, Rotor Sails and kite systems depend on the wind and, as a result, will work best if combined with a weather optimization algorithm. The wind is a variable element, and only with the right weather-related data will ships be able to refine their sail strategy to gain maximum advantage.

Another emissions reduction strategy the sector is experimenting with is slow steaming. It refers to ships deliberately reducing their cruising speed below their design speed to save fuel and reduce emissions. Slow vessels that combine this approach with a route optimization algorithm will be able to travel more efficiently, finding the best compromise between speed and emissions. 

Weather routing helps to address just-in-time arrivals, too, by providing an accurate window for when ships can be expected in port. This reduces the emissions they burn while waiting out at sea. It is also a win for port authorities by enhancing their ability to coordinate traffic flows and optimize logistical operations. 

“Weather routing is both a quick fix and a long-term solution,” says Dr. Precioso. “It can be incorporated now—easily, quickly and cost-effectively—and it can be used in conjunction with a variety of other emissions-savings initiatives. It’s an essential tool that the sector can’t do without.”

Specific answers to specific problems

Weather Navigation is still being developed and hasn’t yet been made commercially available. However, the team has launched an online portal for interested parties to sample. Users can input their proposed trip and receive detailed information about the optimal route, weather patterns, velocity recommendations, fuel consumption and emissions. The tool’s availability is likely to evolve going forward—sector interest in the technology is there, and the environmental and economic urgency is clear. 

Looking ahead, Dr. Precioso is confident that in five to ten years, many ships will be using the green technologies mentioned in this article—and others still in development. “I believe more and more ships will be sailing slower,” he affirms. “Others will be using sails. All will want to reduce their fuel consumption. And amid these changes, we will need to be more efficient than ever with the routes we use.” 

He also expects this to lead to increased specialization in individual technologies. More people are likely to join the conversation, with researchers and experts in different fields getting involved and new branches of innovation developing. Different tools are required to traverse the open ocean compared to small seas, archipelagos compared to arctic routes, and unique ideas are going to be needed for each scenario. 

“It’s going to take a collective effort,” he says. “And instead of one all-encompassing solution, we are likely to see specific answers to specific problems. With all of these combined, we will ultimately see change. But it’s going to take time. Carbon neutrality in this sector is still a long way away—likely decades.” 

Weather routing is set to play a major part in this transformation. IE University’s research, together with its expert partners and global network, is helping to turn the tide on maritime emissions—one optimized route at a time.