Efforts to curb emissions of a powerful greenhouse gas commonly produced as a by-product of refrigerant manufacture might be falling short, and it seems eastern China is a major culprit. Nature: The hydrofluorocarbon gas, HFC-23, is around 14,700 times as powerful as carbon dioxide at warming the globe and has long been the subject of national and international climate-change mitigation efforts. Those efforts gained new traction nearly a decade ago when China and India — the world’s largest producers of the chemical — agreed to dial down its emissions. New research, however, confirms that emissions continued to rise in subsequent years, and an analysis of data from atmospheric-monitoring stations suggests that factories in eastern China are responsible for nearly half of the total.
The rogue emissions are one of several air-pollution sources under discussion at the latest meeting of the Montreal Protocol, held in Nairobi, Kenya, this week. Signed in 1987, the Montreal Protocol is generally considered the most effective international environmental treaty in history, having halted the destruction of the ozone layer while also slowing down global warming. But scientists have often played a role, scanning the atmosphere for chemicals, such as ozone-depleting chlorofluorocarbons (CFCs), that governments have agreed to phase out. “Science has been instrumental in evaluating compliance under the treaty,” says Megan Lickley, a climate scientist at Georgetown University in Washington DC.
