Scooters Cause Smog in Taipei
Anne Stephenson
By Anne Stephenson,
Campus Outreach Coordinator,
Clean Air-Cool Planet
As you’ve discovered from Claire’s earlier post, she and I are in Taipei for climate action planning workshops for Taiwanese schools and universities. Our workshops went really well (more on that later) but first a post on Taipei in general…
At first glance, Taipei is a carbon management dream-city. It is unbelievably dense. It is 104.9 square miles, which is almost a 10th as big as the Greater Boston area. But its population is over 2.6 million, making its density per sq. mile almost double that of Boston. Its subway system (the MRT) is like a dream… quiet, clean, fast, with train after train after train. The MRT has a 94% satisfaction rate among its riders (Autopia Planes, Trains, Automobiles and the Future of Transportation All Subways Should be Like Taipei’s Marvel of Mass Transit), and is consistently rated one of the best in the world.
I arrived at our carbon management workshops totally jealous of the Taipei-based schools. Here, finally, were schools that didn’t have to convince their students to carpool or live on campus rather than drive alone. Alas, that was me seeing the MRT with the eyes of a tourist. Of course, the MRT doesn’t serve all of Taipei, or those students living in Taipei County. That, combined with low gas prices, makes scooters a popular option. While of course scooters are not as efficient as the MRT, they are pretty fuel efficient and therefore cheap to drive.
The challenge for schools and universities, like that of our host National Taiwan Normal University (NTNU), is finding the space for students to park scooters. But the environmental cost is more than the simple math of the emissions factor of the MRT vs. that of gasoline, plus the carbon impact of paving parking lots. Taipei’s smog problem is almost entirely created from scooter emissions and the soot covers everything. Because two-stroke engines like those of Taipei’s scooters suffer from incomplete combustion, they have far more particulate emissions than the average car. In fact, according to the non-profit organization Envirofit, one carbureted two-stroke scooter engine produces the pollution output of 50 modern automobiles.
Thankfully my new obsession with scooters coincided with my friend Cayce’s trip to Italy, and he’s been able to brief me on the latest in scooter efficiency. Aprilia and Piaggio, two Italian scooter companies, are selling direct injection scooters, which are vastly cleaner and more fuel efficient due to how finely the fuel is atomized. According to Cayce, these newer scooters are capable of up to 120 mpg, with minimal emissions. Perhaps even more encouraging is the work done by Envirofit, which installs direct injection retrofit kits in older scooters in Southeast Asia.
As you’ve recently read in Brooks’s posts, we must focus our attention on buying time for the arctic by focusing on the reduction of short-lived pollutants like methane and black carbon for the recent agreement in Copenhagen will not save the arctic. Until this trip, I had trouble wrapping my mind around the significance of black carbon as a short-lived forcer. Sure, I understood the principle of albedo, but it seemed hard to imagine it was a big impact (sorry Brooks). I now get it. I see that the albedo of this city has changed — white buildings could be (charitably) described as gray but are more black than anything. I can see how a little scooter smog can go a long way in turning glaciers from white to gray.
As cities like Taipei grow warmer, the human health impacts of urban heat island effect will be far more deadly because of the poor air quality. Claire and I fly home tomorrow with new perspectives on climate impacts here – urban heat island being a big one. And our workshop was a great introduction to carbon management challenges here – but scooter retrofits isn’t one of them. The technology exists; the only challenge is the sheer number needed.
Tags: arctic warming, carbon footprint, Carbon Management, carbon neutrality, COP-15, transportation
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January 2, 2010 at 4:28 am
It helps a lot that the fuel is finely atomized because it is injected with compressed air. But the main reason the Envirofit kits stop so much pollution is related to a big problem with two-stroke engines…..
they send a large portion of the gasoline out the tailpipe, unburned. Two-strokes don’t have valves. They have ports….holes in the side of the cylinder. As the piston goes down, forced by the explosion of gasoline, it passes the exhaust port and the hot gases go out the exhaust pipe. Continuing down, the piston passes the intake port, and gasoline mixed with air enters the cylinder. BUT, the exhaust port is still open, and some of the fuel goes out that port as the piston rises. Envirofit solve this by injecting all the fuel into the cylinder after the piston rises far enough to close all the ports, so no fuel escapes. It makes a huge difference in the amount of pollution.
March 17, 2010 at 2:40 pm
I had read back in 2004 or 2005 that Taipei had banned the sale of new two-stroke scooters. Is this ban in effect?