Last March, the whole world saw one of the largest cargo ships in existence – 400 metres long, weighing 265,000 tonnes, loaded with 20,000 shipping containers – get stuck in the Suez canal. For six days, tiny tugs tried to nudge the Ever Given off a sandbar. Waiting at both ends of the canal were more than 300 cargo ships and tankers, carrying petrol, semiconductors, microchips, scrunchie hair bands, sneakers, hand-held travel steamers, ice-cream-makers, novelty socks and electric milk-frothers. As the global supply chain ground to a halt, we became aware that 90% of everything in our homes – clothes, appliances, food – has, at some point, been transported by sea.
Cargo ships burn some of the dirtiest oil going, known as bunker. Made from the sludgy leftovers of petrol…