Pressure on China’s leaders to cut pollution from coal is likely to intensify – potentially hurting Australia’s exports – with new research showing Beijing’s air quality will get worse with climate change.
The Chinese capital’s ring of mountains to the west and north naturally traps pollution, especially in winter.
But a warming world is projected to increase the frequency of the most severe pollution events by half, according to research published on Tuesday in the Nature Climate Change journal.
The duration of events similar to the “Airpocalypse” of January 2013 – when pollution levels soared to beyond 20 times the level recommended by the World Health Organisation – will rise by 80 per cent, the study found.
Using 14 climate models, the research predicted a more stagnant air mass over northern Asia and a reduced land-sea temperature difference during winter, leading to weaker north-westerly winds, said Wenju Cai, a senior CSIRO scientist and lead author of the paper.
“If the air becomes stable, the air pollution cannot rise up and the wind is not there so it cannot be taken away,” Dr Cai said. “Then it becomes a serious problem.”
While the pollution had been getting worse in recent years, there was not enough data to determine how much climate change had already had an impact, he said.
Even so, the expected pattern may already be playing out. These include northerly winds often failing to reach Beijing and sometimes being replaced by southerlies that dragged in heavy industry pollutants from cities to the south that cloaked the capital, he said.
The chart below shows PM2.5 particulate levels compared with recommended levels of 25, and the 150 marker that triggers “severe pollution” warnings. Australia rarely reached a level of 25, Dr Cai said.
The research projections suggest the Chinese government will have to do a lot more if emissions cuts already planned are to make a difference in Beijing and many of the nation’s northern cities.
The municipal region this week closed the last of its coal-fired power stations and has forced other big polluters out of the capital in a bid to quell growing public concerns about pollution.
China imports about 10 per cent of the coal it burns, with Australia among the suppliers. A drop in coal consumption in China could affect Australia’s other markets, particularly if China resumes exports.
“Cutting coal would be quite effective – it cuts both particulates and greenhouse gases,” Dr Cai said.
The research indicated China had an incentive to encourage emissions cuts beyond its borders, he added: “Solving Beijing’s air pollution problems requires everywhere and everyone around the world.”
Teng Fei, an associate professor at Tsinghua University in Beijing who specialises in energy and the environment, said the government’s policy to replace coal with gas-fired power in Beijing itself was now complete. More distant provinces also provided electricity from renewables, coal and other sources.
“Most people expect coal consumption will stabilise [in China] in coming years, but whether it will reduce … we’re not too sure,” Professor Teng said.
He is doubtful, too, that China will use its global clout to nudge nations to do more to reduce greenhouse gases than they have committed to as part of the Paris climate agreement.
The 2015 accord, which came into effect last year, relies on a voluntary “bottom-up approach based on commitments by each nation”, said Professor Teng, who served on China’s negotiating team.
“China will not force other countries to do it,” he said.
This story Administrator ready to work first appeared on Nanjing Night Net.