Five years after virtually every world leader agreed to “phase down” the burning of coal for climate reasons, the fuel is more widely used than ever.

© Ahmad Mulia Panjaitan/Associated Press

Five years after virtually every world leader agreed to “phase down” the burning of coal for climate reasons, the fuel is more widely used than ever.

The Iran war is pushing countries to prioritize domestic energy in order to protect themselves from volatile oil and natural gas markets.

A new wave of start-ups are trying to harvest emissions-free energy from inside the Earth, but the industry still faces significant challenges.

© Eduardo Munoz/Reuters