I read an article about how all gas scooters with be banned soon in Shanghai.
http://www.echinacities.com/news/Sha...ooters-by-2016


But that leaves the question, what about motorcycles?

This opens the debate to what really matters in the pollution debate. There is a lot of confusing misconceptions out there.
For one, cars pollute more then scooters.
http://motorscooterguide.net/Article...than-cars.html

Taken from the article above,...
"Figuring out carbon (aka carbon dioxide or CO2) emissions is easy because you just have to look at how much fuel you’re burning. If a scooter burns less gas then a car then it’s producing less carbon than a car. Simple. So virtually every scooter produces less carbon than even the best cars. The biggest maxi scooters tend to be about on par with fuel efficient hybrids, as they both achieve about 45 mpg and thus produce similar carbon. Thus the claim that scooters are worse is dead in its tracks if you’re referring to carbon pollution and climate change."

Unless your talking about 2 stroke scooters,... those can pollute as much as a car but they are phasing out as no one manufactures them now since they are old tech.

The other thing is not all 4 stroke scooters are equal. Honda puts catalytic converters on their scooters before the exhaust gets to the muffler. This combined with automatic engine shut off start throttles for stop n go really puts them in a class of their own. I believe gas scooters can work in a highly populated city and still have blue skies, if other pollution contributing factors are handled.
Newer electric scooters are ideal, not the slow ones but the ones equal to a real 125cc. SH should look into a way of allowing and plating a high powered electric scooter to be allowed to ride in the other lane with gas counterparts. A Scooter such as this one http://www.gogoro.com/ In Taiwan you can see these riding the road as fast and as normally as the 125cc gas counterparts.

I have a feeling the biggest contributing factor in air pollution in SH are the factories. Even ones far away can catch down-winds or drifts into the city. If SH really wants to tackle it's air pollution problem it needs to push it's factories much further away from the city.
Now with Disneyland opening up it looks like they are doing just that.
http://qz.com/497132/china-will-clos...as-blue-skies/

The next problem for SH after it pushes all it's factories back are the high % of cars driving around with horrible exhaust muffler systems. I have seen tons of buses and cars there last time with pillowing amounts of white/black smoke coming out from burned out mufflers and cats no longer filtering any carbon emissions. This should be a big fine. Maybe they cracked down on this since last time I was out there (2012)

The last problem are normal cars polluting the air. Hybrids obviously pollute a lot less in a stop n go environment like SH.
What would make a HUGE difference in the air in SH would to make a law like after 2016 all SH plated cars must be hybrids.
That would make a HUGE difference and really clear the air in SH.
But, banning 125cc four stroke scooters in SH will most likely result in minimal results since truly they are not the main source of the problem, especially the hybrid honda scooters which pollute next to nothing.

Again tackle the problem at the source.
Cars and factories, not gas scooters.
Hybrids come in all shapes and sizes from SUV's to Porsche supercars and Ferrari hybrids.
There is a hybrid out for everyone's tastes including those wanting to show off.

To really get blue skies in SH it's a no-brainer make hybrids the only type of cars allowed in the SH area.
Push the factories out a good 500+ kilometers away from the city.
But banning 125cc gas four stroke gas scooters in the city? That would most likely result in the air index quality going from and unhealthy 170 to an unhealthy 163 or something.

Just restrict and reduce the pollution from the 2 biggest contributing factors and be done with it. Simple. Just my 2 cents.