China, the world’s biggest emitter of greenhouse gases, could peak in emissions by 2030 or earlier, says a study from U.S. researchers who foresee Chinese demand for appliances, buildings and much industry reaching “saturation” around then.

The study by energy and emissions experts at the Lawrence Berkeley National Laboratory in California adds to a growing body of studies that say China could reach its maximum output of carbon dioxide (CO2) within two decades.

That matters for more than China. Its emissions path will be crucial to determining whether the world can restrict total greenhouse gas emissions to levels less likely to trigger dangerous climate change, such as more intense droughts, floods and storms that threaten crops and economic growth.