It is easy to see the pollution problem in an industrial city like Yinchuan in northwestern China but it is hard to realize this is typical across the world's most populated country.
The culprit is sulfur dioxide from coal, which is burned for everything from making electricity to cooking dinner. China produces twice the sulfur dioxide as America does, and by some estimates China may one day generate five times more than what we see today.
That's why just breathing is making Dr. Jiang's patients sick. He knows of only one cure, and it's not medicine.
The best cure is to leave for the countryside, he says.
If China's air pollution seems like a problem just for that country, think again. The stuff spewing out in China has now been detected in the United States, and some suspect it's beginning to affect the U.S. climate.
In California, Professor Tom Cahill tracks pollution across the Pacific, and a lot of what he sees these days comes from China.
"And these things...are coming from manmade sources in China, and laced in those materials are things like arsenic, lead and zinc," Cahill says.
A lot of early-computer modeling of Chinese pollution's effects on the global climate is turning out to be just plain wrong. This is why a massive new study with ground and air monitoring across Asia starts next year.
"We don't really know what the Chinese aerosol does. If it's full of soot, then it may actually heat the Earth. So until we know a better number on what those things are, we can't even do the calculations," Cahill says.
China is trying to clean up its air, but for the moment the pollution is changing the weather, experts say. Some blame it for the worst flooding that China has seen in its recent history - taking 4,000 lives.
For China and America, it's going to get a lot worse before it gets better.