I'm wondering if there have been factories opening up recently in kunming that have contributed to what appears to me a very rapid and sudden decline in air quality which I find difficult to attribute solely to cars or construction. yankee?

No idea, sorry.

Very few factories exist in Kunming. Not that Kunming wouldn't love to have them, but logistics and lazy labor pool make Kunming a very unattractive place to open one.

However, the 2nd ring road and beyond is just one apartment construction site after another. Add in the growth in trucks and cars others have mentioned plus a drought, you have more than enough reasons why Kunming air is on the fast track downhill. Whether this can be reversed in the future, or we will end up like Chengdu will remain to be seen.

Many USA cities 30 years ago had the same or worse air quality that Kunming is facing now. Taking cars and trucks off the road did not seem to be a reasonable option at the time so all new car and truck engines were required to burn more cleanly or they had to install emission systems. Oil refineries where also required to start producing cleaner safer fuels. The same quality of diesel fuel used by trucks and buses in china can only be used by farmers in the USA. Also did not hurt that many of the more polluting industries moved operations to other countries most notably china. Even now the remaining coal burning power plants are being required to install equipment to greatly reduce their emissions and many are converting to cleaner burning natural gas. Even if China makes the promised changes it could take a long time to see measurable improvements. It took Denver a city with many similar physical characteristics a long time to clean up there air.

Its hard to know how bad PM2.5 readings were in the USA before they started recording them in 1999 www.epa.gov/airtrends/pm.html

But from the levels since then it seems that PM2.5 for the last 13 or so years is MUCH lower in the US than what we see in China.

With lack of data its hard to say if cities in the US had similar or worse air qualities to what we have in Kunming at the moment (PM2.5 is supposed to be 65 today in Kunming.)

The argument that China uses to explain its high current pollution is that it's a developing country, that like the west when developing they are in a high pollution phase, but I don't buy that argument.

The Chinese government learns quickly and spends to get the best technology when they want,, weapons, Subway systems, space program, trains, luxury state of the art cars etc

I think one of the main reasons why pollution is such an issue here is the government cannot make money out of it so they don't want to make the needed investments in clean technology.

If we compare countries, pollution is currently quite bad in China, but in terms of accumulated green gas, it's still very far from, say the US or the UK. And currently, the US is the biggest polluter per capita, four times ahead of China.
It is said that China is projecting to be the world's largest user of solar and wind energy. There will probably be quite a lot of coal burning to produce turbines and solar panels for the growing energy consumption of 1.4 billion people, and it will probably be decades before those sources of energy have an impact on the quality of air.

Pollution in China is more striking because it's currently happening, and unlike the West in development times, they have to produce not only for their billion people, but also for the entire world. We are also witnessing it right in the middle of it.

There have been leaps in some solar technologies. 6 years ago they were using flat panel water heaters on the roof. This is technology that has been around for decades. This was the best available at the time.

Now the tubes with the heat exchangers are common. These are very efficient, our neighbor's often boils and spouts steam. Such is the demand in China that the industry has leapt onto new technologies.

I firmly believe that this will drive technology in other areas too, including energy, and China will be a leader. Why? Because USA and EU have a legacy energy industry. It is not realistic to rip it out and start again. However, China has a lot of new infrastructure to build, including energy production capacity. There is an economic driver for development, not just the political idea to do it.

I agree with tigertiger, but here's a reality check.

China is the world #1 consumer of coal.
China is the world #2 consumer of oil.

With 20% of the world's population it would be difficult to NOT be a leader in those categories. I prefer status that put things on a per capita basis.

How much of China's ongoing pollution is going to revolve around the density of its people. China has 1.34 billion people compared to the USA's 314 million living in a country which is 300,000 sq miles smaller than the usa. Take out Alaska and the parts of China which are not very livable and the sizes are probably fairly equal. Then you need to take a very high percentage of China's population and place it in the eastern half of the country where in usa the population though more dense on the east coast states it is still more evenly spread out. Question for a scientist here, if 1.34 billion people were to all fart at the same time how much methane gas would that produce?