Hydrogen’s moment is here at last

HYDROGEN HAS been controversial ever since the tragedy of the Hindenburg, an airship filled with it that went down in flames in 1937. Boosters say that the gas is a low-carbon miracle which can power cars and homes. The hydrogen economy, they hope, will redraw the energy map. Sceptics note that several hydrogen investment drives since the 1970s have ended in tears as the gas’s shortcomings were exposed. As we explain, the reality lies in between. Hydrogen technologies could eliminate perhaps a tenth of today’s greenhouse-gas emissions by 2050. That is a sliver—but, considering the scale of the energy transition, a crucial and lucrative one.