I too have been to both these cities multiple times, spanning since 1983 all the way up to 2007.
I've seen significant differences between the capitalization then and now. As well as pollution levels then and now.
China has deffinitively gotten far far worse in pollution.
But I do share the assessment of Shanghai vs LA to a certain extent.
If LA had the same humidity level that Shanghai has LA would be far worse (all else unchanged).
Chinese are far far less reliant on the internal combustion engine than Americans. The top method of getting from A to B in China is still the bicycle followed then by public transport and then followed far later by ICE's. However the car is quickly catching up and congesting cities creating an urban Ozone that traps pollution in the cities even more.
When I visited Beijing in 1998 it was terrible, I literally could not see much but sillouettes of buildings that were but a mere 100 meters away. My last visit to these two cities just last year though proved different. Beijing had seriously cleaned up - thanks largely to it's extended brand new light rail, as had Shanghai.
There are still several more rual areas that are subject to heavy industrial pollution but it is clear that they are cleaning up.
As is the case with the Shandong city of
Rizhao, where get this,
99% of all heating is from solar energy and overwhelming majority of street lights get their power from solar panels.
Any such city in the US? Europe? Not that I know of.