Danger Dust

Decarbonization of transport is underway. Here are future fuel predictions.

As the world races to decarbonize everything from the electricity grid to industry, it faces particular problems with transportation — which alone is responsible for about a quarter of our planet’s energy-related greenhouse gas emissions. The fuels for transport need to be not just green, cheap and powerful, but also lightweight and safe enough to be carried around.

Every energy solution has its pros and cons. Batteries are efficient but struggle with their weight. Hydrogen — the lightest element in the universe — packs a huge energy punch, but it’s expensive to make in a “green” way and, as a gas, it takes up a lot of space. Liquid fuels that carry hydrogen can be easier to transport or drop into an existing engine, but ammonia is toxic, biofuels are in short supply, and synthetic hydrocarbons are hard to produce.