Is there a substantial reserve of hydrogen fuel stored beneath the Earth’s surface?

For the past few years, companies and prospectors around the world have been searching for natural hydrogen reserves underground, spurred by estimates that there are trillions of tons of natural hydrogen on Earth. The discovery of this geological hydrogen could accelerate the transition away from fossil fuels. However, despite some tantalizing hints that vast reserves existed, exploration was largely unsuccessful.

Until recently, most geologists…