RACHEL MARTIN, HOST:
China's efforts to control the coronavirus have meant many residents stayed at home and factories just shut down. That had an unintended effect - less air pollution. Cleaner air can improve public health, maybe even save lives. Joining me to explain why that isn't so simple in China right now is NPR climate correspondent Lauren Sommer. Hi, Lauren.
LAUREN SOMMER, BYLINE: Hi, Rachel.
MARTIN: All right. First off, just explain how big the drop was in air pollution in China.
SOMMER: It was significant. It was down a quarter to a third in some places compared to the same time period last year. And that's because people have been driving less. But the big thing is coal consumption because power plants and industry has ramped down. We're starting to see an uptick as China's activity is increasing, and that hasn't been true everywhere. Beijing actually saw an air pollution spike outdoors in February because there was a weather pattern trapping the pollution there.
MARTIN: OK. So if power plants and factories were running less, that also means carbon emissions dropped.
SOMMER: That's right - about a quarter. Now, that's a tiny fraction of China's yearly emissions, but it's still substantial because China is the largest emitter of greenhouse gases in the world. So even that short period of time in China equals what a state like Illinois or Ohio emits in an entire year.
MARTIN: Wow. So even though it's only a little bit over a month that we're talking about for these improvements, it's substantial enough to make a difference in people's lives.
SOMMER: Yeah. Even a short-term drop in something like air pollution can actually have benefits. And a good example of that is the 2008 Summer Olympics in Beijing. To improve air quality during the games, government officials limited car traffic and they shut down factories. And researchers actually tracked people during that time period, and they saw improvements in cardiovascular health and lung health. They also found that babies whose mothers spent their third trimester during the Olympic Games were born with heavier birth weights.
MARTIN: OK. So that was years ago. Are people in China right now seeing those benefits?
SOMMER: Yeah, it's a good question because the potential is really big here, you know. It's estimated that air pollution is linked to more than a million deaths per year in China. So I put that question to Jill Baumgartner. She's an environmental epidemiologist at McGill University.
JILL BAUMGARTNER: It would be a mischaracterization to say that the coronavirus was beneficial to health because of these air pollution reductions. In addition to tens of thousands of people who were impacted by the virus in China, you know, it placed stress on people's lives and on the health care system and lots of other sectors.
SOMMER: She says that people with health conditions other than COVID-19 may have not been getting the health care they really needed during this time period. And people may have spent more time indoors, so they would have been exposed to more secondhand smoke potentially or indoor air pollution from coal-burning stoves which are used in some parts of rural China.
MARTIN: Presumably, though, as the coronavirus is contained in China, this drop we've seen in emissions is going to be erased by the fact that the factories, the power plants, they're going to go back online and return to normal, right?
SOMMER: Yeah. And, of course, there's an incredible human toll here associated with this reduction in emissions. And there's also a high likelihood that it's going to be cancelled out as China tries to make up for its economic losses and really starts ramping up power plants and factories in the near term.
MARTIN: NPR climate correspondent Lauren Sommer, thank you.
SOMMER: Thanks. Transcript provided by NPR, Copyright NPR.