Friday, November 28, 2008

update on fall air quality in beijing

Yesterday a friend commented that it seems like the air quality in Beijing this fall has been much better than last fall. Turns out he's right:

(For background, see this post on Air Pollution Index (API)).

Although the air quality since 9/21 hasn't been as good as it was during the Olympic period, the average particulate matter concentration in the air this fall has been over 20% lower than the same time period last year and almost 40% lower than the same time period two years ago. Perhaps the one-day-a-week car ban is working?

FYI, the average PM10 concentration this fall of around 100 ug/m^3 is actually right at China's annual air quality target, though still five times higher than the WHO recommended annual level of 20 ug/m^3.

Lastly, I want to show again a long time-scale graph of daily API vs. time in Beijing:

There are two main take-away messages from this graph:

1) The improved air quality of the Olympic period (7/20 - 9/20, 2008) is quite apparent.
2) We have yet to see a major pollution spike (say, API above 200) since the Olympics ended...

highlights from BAQ2008 - ICCT and diesel emissions

This is the third in a series of posts noting some random highlights from the BAQ2008 conference. Here I'd like to feature a few great slides I saw presented by Dr. Anup Bandivadekar of the International Council on Clean Transportation (ICCT). (Side note: Dr. Bandivadekar is the lead author of MIT's "On the Road in 2035: Reducing Transportation's Petroleum Consumption and GHG Emissions.")

The presentation I heard by him was called "Diesel Passenger Cars: Safeguarding Air Quality and the Global Climate in a Shifting Market."

The presentation begins with an introduction to the "diesel dilemma," which I will briefly summarize as follows: diesels are more efficient than gasoline vehicles (therefore are better for energy security / CO2 emissions reductions), but pollute more, especially NOx and PM (therefore are worse for air quality). Certain areas of the world (most notably Europe and countries which have followed Europe's precedent) have promoted diesels for the former reason by subsidizing the cost of diesel fuel and setting higher emission limits for diesel vehicles as compared with gasoline vehicles.

As diesel engine technology and emissions control systems improve, though, there is a growing call to eliminate any special policy treatment afforded to diesels, and instead adopt "technology neutral" environmental standards. (Note: the US and Japan's technology neutral standards are one reason diesel passenger vehicles have not had large penetration in those markets.)

Indeed, Dr. Bandivadekar's conclusion states:
Diesels don't have to be the problem...

The trade-off between air pollution and GHG reduction is artificial -- solution lies in strict, technology-neutral emission standards
But there are two additional key points that Dr. Bandivadekar makes that I want to feature.

The first is that low sulfur diesel fuel is required if advanced diesel emission control systems are to be installed on vehicles. His presentation features an excellent slide showing graphically the PM reduction potential vs. diesel fuel sulfur content:

As standards become more and more stringent, it is critical that fuels and vehicles be treated as a system, especially with regard to sulfur content. Unfortunately, however, many Asian nations still have extremely high sulfur content in their fuels:

This high sulfur content in many areas, including China outside of Beijing (this point to be expanded on in another post), is a major limiting factor to the introduction of cleanest technology diesel vehicles.

Another fascinating point that Dr. Bandivadekar raised is that greenhouse gas emissions from diesel vehicles are more than just CO2. Incomplete diesel combustion also results in the emission of "black carbon," another powerful contributor to global warming. When considering total greenhouse gas emissions, diesels only have an advantage over gasoline when black carbon emissions are controlled:

(In the above slide, "DPF" refers to "diesel particulate filter," an emissions control device that requires low sulfur fuel to operate properly.)

Therefore, the need for immediate implementation of low sulfur diesel fuel and advanced diesel emission control technology is supported from both air pollution and greenhouse gas reduction perspectives.

Lastly, I'm posting up one of Dr. Bandivadekar's first slides, the ICCT's excellent Bellagio Principles:

highlights from BAQ2008 - Chris Cherry and e-bikes

Electric bikes (e-bikes) may not be on the tip of the sustainable transportation community's tongue yet, but I think they should be, and in this post I'll explain why.

Dr. Chris Cherry of UT Knoxville is a (the?) leading international expert on e-bike development in China. His BAQ2008 presentation, "Environmental Impacts of E-bikes in China (and Beyond)," did an excellent job framing the e-bike discussion and current status.

First, take a look at this graph of recent e-bike production in China:

2007 e-bike production in China was over 20 million units, two and a half times more than motor vehicles. Anyone who has traveled regularly to China recently can attest to the reality that e-bikes are proliferating like crazy in Chinese cities. The sheer magnitude of these numbers (and the rapid rate of increase) demands that we investigate the energy, environmental, and social impacts of e-bikes.

Regarding the energy and environmental impacts, here is an incredible table Dr. Cherry developed on per passenger-km emission factors of various different transportation modes in China:

The values in the table are colored by impact. As expected, of the modes compared here, bicycling is the only one that receives "greens" across the board, while cars and motorcycles are generally "red" for highest impact. E-bikes, on the other hand, are competitive with buses for environmental impact for most pollutants except lead. (The extremely high lead emissions result from the e-bike batteries, which are comparable to car batteries; this makes it absolutely critical that lead pollution from increased e-bike production and use be controlled with lead acid battery production management and recycling programs.)


In my opinion, e-bikes should be given high priority as an urban sustainable transportation solution. E-bikes provide much greater urban mobility than buses, with comparable environmental impact, but result in significantly less air pollution and greenhouse gas emissions than cars or motorcycles.

However, e-bike development (and modal shift) should be carefully managed and understood. Direct modal shift from bikes to e-bikes clearly results in a net negative environmental impact, while the net environmental impact of modal shift from buses to e-bikes is unclear. Exploring this question, another slide of Dr. Cherry's presentation shows the results of mode choice surveying in Kunming:

The fact that most respondents chose an e-bike over a bus or standard bicycle may indicate that the e-bike proliferation has had a net negative environmental impact in Kunming.

That having been said, though, the primary, future environmental challenge in the transportation sector in China is controlling the impacts of a rapidly motorizing population. Therefore, the proliferation of e-bikes should be considered both in the context of current modal shift (e.g. what transportation mode would you choose today if not an e-bike) as well as the context of future behavior and mode choice. For example:

- How has the use of an e-bike transformed a customer's perceptions of the future need and use of a motorized vehicle?
- Has the owning of an e-bike delayed the inevitable purchase of a private car?
- Even if a car is purchased, what trips are the e-bikes still used for?

Most of all, whether you are for or against e-bikes, due to the massive growth in their production, at least two things are clear:

1) There is much more research to be done (modal share, lead pollution, safety, impact on regular bikes);
2) It is time for the sustainable transportation community to expand greatly the discussion of e-bikes and their impacts. (I told Dr. Cherry after his talk that at BAQ2010 there should be a whole panel on e-bikes, not just one presentation!)

Thursday, November 27, 2008

highlights from BAQ2008 - IEA

As mentioned in my last post, I'd like to feature some highlights from the BAQ2008 conference earlier this month in Bangkok. I haven't had a chance to go through even nearly all of the presentations, but there are some key slides / conclusions that I either remember from attending or found while browsing the files online that I'd like to post up here. Some of these will be a little out of context, but in all cases I will post the link to the original presentation for further info.

First, I'd like to post highlights from presentations I heard from Lew Fulton and Pierpaulo Cazzola of the IEA, based on energy demand projection research that went into the World Energy Outlook and Energy Technology Perspectives. (Side note: the just-released WEO 2008 Executive Summary is a must read.)

To start with, here are a couple of great slides from Mr. Fulton's presentation, "Transport, Energy, and CO2 in Asia: Where are We Going and How Do We Change It?":

The above slide shows IEA projections of global car stock by region (y-axis is in millions). Note the exploding dominance of China, especially after 2015-2020. This graph highlights both the incredible challenge we face to limit the energy and environmental impacts of vehicles worldwide, as well as the critical importance of guiding the inevitable growth of vehicles in the developing world in as sustainable a direction as possible.

On energy consumption and greenhouse gas emissions, Mr. Fulton proposed that it is both economically and technologically reasonable to target a 50% reduction in global light duty vehicle energy intensity by 2030. This loosely means reducing average car energy consumption from approximately 8 to 4 l/100-km. Note that some vehicles, such as the Prius, already achieve a fuel economy in this range.

However, current policies are not even close to guiding the vehicle fleet to this target. The following slide shows baseline vehicle fuel economy projections to 2050, taking into account all current legislation:

There is clearly a gap between what legislators (and the vehicle industry) are targeting, and what is currently possible (and required to meet necessary global GHG reductions).

Looking out to 2050, the IEA proposes that the majority of CO2 emissions savings from the transportation sector will come from improvements to conventional gasoline and diesel engines and traditional hybridization. This was surprising to me, as I expected electric vehicles and plug-in hybrids to play a bigger role. Additional savings are projected to come from some combination of electric vehicles and fuel cell vehicles, but the extent of those savings will depend on future technology improvements:

Fortunately, in the case of conventional engine improvements and traditional hybridization, pricing (in theory) shouldn't be the issue, as the fuel savings are on par with the additional technology cost for these vehicles:

Lastly, I'm posting up the conclusion slide from a talk with some overlapping content given by Mr. Cazzola called, "Fuel Economy as a Means to Avoid Future Greenhouse Gas Emissions from Transport":

The conclusion about monitoring increases in weight and power is critical, and something I will address in another post.

Tuesday, November 18, 2008


It's been a busy November for me so far, mostly due to tons of meetings and conferences. Most recently, I spent the past week down in Bangkok for the Better Air Quality 2008 (BAQ2008) conference.

All in all, the conference (actually my whole trip to Thailand in general) was just incredible - one of the best conferences I've ever attended. I had hoped to blog about the conference while down there, but internet access was sporadic for me, plus I was pretty engaged with meetings / discussions / panels for the entire time.

Over the next week, I will try to post up highlights from some of the presentations. In the meantime, I want to publicize the program, from which you can download most of the presentations. If you want to become an overnight expert on air quality in Asian mega-cities (plus a myriad of related issues like transport demand management, urban planning, health effects, links to fuel economy and GHG emissions, role of technology) these presentations are a fantastic place to start.

Before expanding on individual panels and presentations, though, I want to sing the praises for a moment of the Clean Air Initiative for Asian Cities (CAI-Asia). I was somewhat familiar with the group before, especially their excellent work summarizing Beijing Olympic air quality data, but it wasn't until this conference that I gained such tremendous respect for their dedication, organization, impact, and spirit. In just a few years, CAI-Asia has become the leading voice promoting partnerships and the sharing of air quality improvement experience throughout developing Asia. The incredible breadth and depth of this conference are testaments to the way they have catalyzed governments, NGOs, academics, and the private sector to work together towards the common goal of improving air quality in all cities.

Plus, I have to give them credit just for being so much fun...and recognizing that conferences are so much better when they are punctuated with singing, jokes, props, inspirational music, and the occasional strobe light...

Before signing off, I also wanted to mention that, earlier this month, I attended the very good 4th Regional Air Quality Management Conference from 11/6-7. Fulbright scholar Scott Moore has a good summary of the first day up on his great new blog, China Greenspace. As time permits, I will try to post up some comments on the second day, especially the transportation panel.