Image: REUTERS/Jason Lee

In December 2016, China’s environmental authority issued a ‘code red’ in Beijing. The highest level of a four-tier system, the alert warns residents when pollution has reached critical levels.

Schools were closed, thousands of vehicles were ordered off the roads, some factories ceased operations, and residents were told to stay indoors.

Image: China Xinhua News

China knows that its people are choking on smog. In 2013, Premier Li Keqiang declared war on pollution, with a pledge to reduce the country’s reliance on coal-fired power and to invest heavily in sources of renewable energy. The plan also included shutting down ageing cement and steel plants, a major source of the pollution.

And a recent study suggests that things may be starting to improve.

Image: Environmental Research Letters

Scientists from Tsinghua University, Beijing, undertook a study to see if the government’s plan was working.

They measured the amount of PM2.5 concentrations in the air using satellite- and ground-based observations. PM2.5 is a measurement of fine particulate matter. These tiny particles of pollution pose the biggest risk to human health because of their ability to penetrate the lung and cardiovascular system.

The scientists then used a computer model to estimate the population’s exposure to pollution across the country. It showed that PM2.5 concentrations decreased by 21.5% over China during 2013–2015, reducing from a measurement of 60.5 μg m−3 (micrograms per cubic meter air), to 47.5 μg m−3.

As a result, the scientists estimated that deaths due to PM2.5 pollution decreased from 1.22 million in 2013 to 1.10 million in 2015, a reduction of 9.1%. The authors of the study say that it “marks the first estimates of the impact of this stringent action plan on pollution levels and mortality rates from 2013 to 2015”.

According to the Global Burden of Disease 2015, outdoor PM2.5 exposure contributes to approximately 1.1 million deaths in China every year.

The World Health Organization says that human health is impacted above a limit of 10 μg m−3.

Image: Greenpeace

A 2016 study by Greenpeace also said that China’s air was getting cleaner. Using NASA satellite images to measure microscopic particles, the study found that levels of PM2.5 had decreased by 17% between 2010 and 2015.

“China’s systematic efforts to combat air pollution have achieved an impressive improvement in average air quality in the country,” said Greenpeace.

Getting tough on pollution

China is getting tough on pollution, according to its national news agency. It’s currently bringing online its latest thermoelectric center in Beijing's Chaoyang district – one of four major gas-fired thermoelectric centers, which together will cut the city's coal consumption by 9.2 million tonnes each year.

Meanwhile, in a pollution crackdown, nine construction companies were caught breaking dust-control rules and were suspended from bidding on projects in Beijing for a month.

The price of a booming economy

Image: REUTERS/David Gray

China’s pollution crisis is the consequence of its rapid industrialization: as the economy grew and factories sprang up, it became the world's largest polluter.

In recent years, however, China has channeled huge amounts of investment and effort into becoming a greener economy.

Earlier this year, the country said that it would prioritize green development and focus on clean technology.