5 Ways Shipping Contributes to Climate Change

Aug 16, 2023 | Our Point of View

Shipping goods is a resource-intensive activity. It’s also an essential part of the global supply chain. Without supply chains, goods cannot be manufactured and sold to consumers. In this way, shipping plays a vital role in the economy and has become one of the fastest-growing sectors in many countries. Consequently, it is also one of the most impactful industries on climate change. Shipping accounts for around 3.5% of global GHG (GreenHouse Gas) emissions and is expected to grow by nearly 20% by 2030. Climate change poses further challenges for shipping. Intense weather conditions increase the risk of maritime accidents while rising temperatures lead to thinner ice cover, which makes navigation more difficult in some areas. This article details the five main ways shipping contributes to climate change – negative externalities that aren’t included in cost pricing or buyer decision-making.


Shipping vessels are ten times denser than rail, 20 times denser than air, and 100 times thicker than trucking. Consequently, they consume high amounts of energy per unit of transported cargo. While the speed and capacity of vessels are crucial for global supply chains, it also contributes to GHG emissions. Turbulence and bow waves created by high-speed vessels cause significant air and water pollution. The average speed of container vessels has increased from about 15 knots to 22 knots over the last 30 years. It could rise further if coastal states impose restrictions on the length of ships to prevent groundings on coral reefs.


CO2 emissions from fuel combustion are the primary source of GHGs emitted by shipping. As the demand for shipping continues to rise, so will CO2 emissions from the industry. Currently, crude oil is the largest fuel source for marine transportation. It is estimated that the energy content of crude will be depleted within the next few decades. After that, oil-based fuels will be replaced with biofuels and electricity. The GHG intensity of marine fuels is expected to increase as demand for them grows. CO2 emissions from marine fuels are only about 15% lower than coal. However, biofuels can significantly reduce GHG emissions from marine transportation since plants absorb CO2 from the atmosphere. Energy savings through more efficient engines and routing can dramatically reduce CO2 emissions from shipping. However, it will not be sufficient to reduce CO2 emissions by the required amount.


Transportation of crude oil from the wellhead to refineries is responsible for around 70% of the CO2 emissions from refining crude. CO2 emissions from transporting crude oil vary depending on the mode of transportation, distance, and energy efficiency. While importing crude oil via marine transportation is the most energy-efficient, it also produces the highest CO2 emissions. CO2 emissions from maritime transit vary depending on the amount of fuel used. Since CO2 emissions are currently not considered in pricing, consumers don’t consider them in their decision-making. The CO2 emissions of marine transportation are emitted in the same region where the crude oil is produced. The CO2 emissions are thus embedded in the price of crude oil.


Global warming impacts the frequency and intensity of extreme weather events, including maritime accidents. The power of extreme weather events has increased over the last decade, with an average annual increase of 0.19 degrees Celsius. The North Atlantic is expected to be the region with the highest growth in the frequency of extreme weather events. The intensity of extreme weather events in this region could increase by up to 70% by 2050. The power of extreme weather events has already created hazardous conditions for maritime transportation. Naval accidents currently cause around 5,000 fatalities and 4,500 serious injuries yearly. The International Maritime Organization expects that the intensity of extreme weather events will result in a significant increase in maritime accidents.


Shipping companies have started to respond to climate change by reducing CO2 emissions per ton of transported goods. Three trends can be expected to reduce CO2 emissions from shipping: The first trend is the development of cleaner fuels. Maritime transportation uses various fuel sources, such as heavy oils, light oils, and gas oils. Improved technologies have led to a significant increase in the efficiency of these fuels. The second trend is the use of larger vessels in coastal shipping. Larger vessels can transport more goods with less energy than smaller vessels. The third trend is the development of more efficient engines. Engine design and the use of new materials are expected to reduce the CO2 intensity of marine fuel.


The global economy can’t function without shipping, and its contribution to the economy is expected to grow. However, more action is needed from industry and government to ensure that shipping remains sustainable. This will reduce the negative impacts of shipping on the climate and the environment while continuing to be an essential part of the global supply chain.

Written By William Benton