A world desperate for a climate-friendly fuel is pinning its hopes on hydrogen, seeing it as a way to power factories, buildings, ships and planes without pumping carbon dioxide into the sky.
But now scientists are warning that hydrogen leaked into the atmosphere can contribute to climate change much like carbon. Depending on how it’s made, distributed and used, it could even make warming worse over the next few decades, even if carbon poses the bigger long-term threat. Any future hydrogen-based economy, they say, must be designed from the start to keep leaks of the gas to a minimum, or it risks adding to the very problem it’s supposed to solve. Some ideas now being tested, like shipping hydrogen in pipelines built to hold natural gas or burning it in individual homes, could cause an unacceptable level of leaks.