Delhi: 442. Lahore: 334. Beijing: 16. These are the levels of PM 2.5, one of the principle measures for air pollution, on November 19.

As Pakistanis and Indians struggle with hazardous air quality, in Beijing – a city once notorious for its smog – the air quality is currently rated as good.

Ahead of the 2008 Beijing Olympics, the Chinese government was so concerned about pollution that it introduced temporary restrictions on cars, shut down factories and stopped work on some construction sites. The measures worked and one study later found that levels of air pollution were down 30% during the period when the temporary Olympic restrictions were in place.

It would take a few more years before the Chinese government implemented a clean air action plan in 2013. Since then, China has achieved a dramatic improvement in its air quality.

In this episode of The Conversation Weekly podcast, we speak to Laura Wilcox, a professor at the National Centre for Atmospheric Science at the University of Reading in the UK, to understand how China managed to clean up its air pollution. But Wilcox’s recent research uncovered some unintended consequences from this cleaner air for the global climate: the pollution was actually helping to cool the atmosphere and by taking it away, it may have accelerated global warming. Wilcox explains:

 What we’re seeing is a removing of cooling that’s revealing warming that’s already there. So the air pollution isn’t the cause of the warming. It’s just letting us see stuff that we’ve already done.

Listen to the interview on The Conversation Weekly podcast. You can also read an article by Laura Wilcox and her colleague Bjørn H. Samset about their recent research on The Conversation.

This episode of The Conversation Weekly was written and produced by Mend Mariwany, Gemma Ware and Katie Flood. Mixing by Michelle Macklem and theme music by Neeta Sarl.

Newsclips in this episode from Voice of America, CBC, AP Archive, ABC (News) Australia, WFLA NBC Channel 8 and PBS.

Listen to The Conversation Weekly via any of the apps listed above, download it directly via our RSS feed or find out how else to listen here. A transcript of this episode is available via the Apple Podcasts or Spotify apps.

This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Gemma Ware, The Conversation

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Laura Wilcox receives funding from the Natural Environment Research Council (NERC), the Research Council of Norway, the Clean Air Fund, and Horizon Europe.