Global treaty is failing to curb ultra-potent greenhouse gas emissions

Emissions of a powerful greenhouse gas released as a byproduct in the manufacture of refrigerants are much higher than reported by governments, suggesting a global agreement to stamp out such emissions is failing.

Under the Kigali Amendment to the Montreal Protocol, signed in 2016, more than 160 countries said they would do their best to eradicate emissions of HFC-23, a gas with 14,700 times more warming potential than carbon dioxide. Data provided by governments suggest emissions have fallen by more…