A report from Reuters says that the world’s crude-steel output in September — 141.4 million tonnes — was the lowest monthly total since February, with mills in China cutting production, as Beijing intensifies its campaign for clearer skies.

Crude steel output in China, which produces roughly half the world’s steel, stood at 71.8 million tonnes in September, 5.3% higher than the September 2016 figure but down 3.7% from August.

Output drops of 30 million tonnes or more are expected in China this winter, as Beijing intensifies its war on smog.

Official figures from China show it has cut 110 million tonnes of legal steel capacity and 120 million tonnes of illegal capacity since the start of last year, but the cuts are only now starting to translate into lower production.

Average global steel prices have increased by about 50% since the 12-year lows of December 2015, according to consultants MEPS, driven by capacity cuts in China, soaring infrastructure spending, and increased trade protectionism.

However, the World Steel Association expects no growth in steel demand in China next year, as Beijing’s infrastructure spending declines and the country resumes its efforts to rebalance the economy and protect the environment.