船舶的动力来自于柴油发动机，通常使用重质燃料油。它是原油炼制后剩余的重质油，粘度很大，在室温下粘稠度类似于花生酱，价格不高但杂质很多，硫含量特别高，可高达35000 ppm, 或者说是欧洲公路交通所使用的超低硫柴油硫含量的3500倍。这就是为什么海洋运输排放的二氧化硫占到全球排放总量的8%。
Ships are powered by diesel engines, usually heavy fuel oil. It is the remaining heavy oil after crude oil refining, with high viscosity. At room temperature, its viscosity is similar to peanut butter. Its price is not high, but there are many impurities. Its sulfur content is particularly high, which can reach 35000 ppm, or 3500 times of the sulfur content of ultra-low sulfur diesel used in European road transportation. That's why marine transportation accounts for 8% of global emissions of sulfur dioxide.
燃料燃烧释放二氧化硫，以废气的形式进入大气中。根据环境条件的不同，二氧化硫很容易与微小的水滴发生反应生成硫酸，这就是酸雨的成因。酸雨的酸度是普通雨水的10-100倍，对树木、植物和建筑物造成损害。如果酸雨不能在大气中分解，则会造成多种危害，二氧化硫被吸入后会造成呼吸道疾病，引发炎症，甚至导致心肺衰竭。2011年丹麦的一项研究显示，欧洲大约有5万多个过早死亡与海运造成的空气污染有关。
Fuel combustion releases sulfur dioxide into the atmosphere in the form of exhaust gas. According to different environmental conditions, sulfur dioxide is easy to react with small water droplets to form sulfuric acid, which is the cause of acid rain. Acid rain is 10-100 times more acidic than ordinary rain, causing damage to trees, plants and buildings. If acid rain can't decompose in the atmosphere, it will cause many kinds of hazards. When sulfur dioxide is inhaled, it will cause respiratory diseases, inflammation and even lead to heart and lung failure. In 2011, a Danish study showed that more than 50000 premature deaths in Europe were related to air pollution caused by shipping.