It leaks very readily, it ignites very readily, it burns with a wide range of air:fuel proportions, it burns with a high flame speed, and it burns hot.
Hydrogen is ... not a good choice for something to reticulate widely around the world.
Edit: That's leaving aside its low energy density. You need three times the volume of hydrogen as natural gas for the same quantity of heat, so existing pipe networks are unlikely to be useful.
Global warming potential is off to the side of all this.
Yet, millions of tons of hydrogen are today produced, transported and used.
There is nothing special about the volumetric energy density of NG. H2 has to move faster, if carried in the same pipe for the same use. Its lower viscosity means it can.
Municipal gas networks used to carry "lamp gas", a mix of CO and H2, in cast-iron pipes.
It leaks very readily, it ignites very readily, it burns with a wide range of air:fuel proportions, it burns with a high flame speed, and it burns hot.
Hydrogen is ... not a good choice for something to reticulate widely around the world.
Edit: That's leaving aside its low energy density. You need three times the volume of hydrogen as natural gas for the same quantity of heat, so existing pipe networks are unlikely to be useful.
Global warming potential is off to the side of all this.