olympic pollution reductions confirmed by NASA satellite

A new study from NASA analyzed satellite measurements of air pollution over Beijing to conclude:

The [Olympic] emission restrictions had an unmistakable impact. During the two months when restrictions were in place, the levels of nitrogen dioxide (NO2) -- a noxious gas resulting from fossil fuel combustion (primarily in cars, trucks, and power plants) -- plunged nearly 50 percent. Likewise, levels of carbon monoxide (CO) fell about 20 percent.

The following images show comparative NO2 levels around China during August, 2005-2007 (left) and August, 2008 (right). Note the disappearance of the color red over Beijing in the image on the right.


Much of the air quality discussion on this blog and elsewhere has been about particulate pollution, not NO2 or CO, so it's nice to see the expanded analysis.

Monitoring of air pollution by satellite is just awesome. Last November, I heard a fascinating presentation by Argonne National Lab's Dr. David Streets on recent developments in satellite monitoring. It is getting so exact, he said, that, "we are exploring the potential of monitoring the change of power plant emissions in China from space." He then showed an example of pinpointing the opening of new power plants in Inner Mongolia through satellite observation:


Note pixel size of ~12km. Incredible.

Related post: final day of temporary air quality measures

paralympics air quality update - 9/6 API missing

The last time I presented daily API data was on August 24th, the final day of the Olympics. With the Paralympics now underway, I figure it's time to take another detailed look at the air quality status.

Since 7/20, the day the odd/even car ban and other temporary air quality control policies went into effect, the graph of daily API values is as follows:

A couple of things worth noting:

1) Though the API was below the target cut-off of 100 for the entire Olympic period, between the Olympics and Paralympics we saw one day, 8/29, in which the API shot up to 110.

2) The API data for 9/6 is conspicuously missing. (As always, my source for API data is the query at the bottom of MEP's air quality page.) Does anyone out there have this data point, perhaps from the Beijing EPB? I seem to remember that day - the day of the Paralympic opening ceremony - being particularly hazy, but I didn't check the data then. Missing data is always concerning, of course, but especially here.

Still, though, the results for overall air quality since 7/20 are remarkable. The average API from 7/20-9/9 of this year is 63; during the same period last year the average was 89.

Lastly, the weather has seemed quite strange recently here in Beijing; over the last few days I've seen two of the heaviest thunderstorms I can remember in China. Anyone agree?

paralympics underway!

Last Saturday night, the Paralympics began here in Beijing with a gorgeous and moving opening ceremony. Apparently you can watch it online here, though I can't seem to get the site to work from within China.

One of the most powerful moments of the ceremony was the lighting of the torch (which, by the way, it's nice to see blazing again!). Three-time high jump gold medalist Hou Bin hoisted himself, his wheelchair, and the torch by pulley from the floor of the stadium all the way up to the base of the cauldron.


It took him over three minutes to reach the top, and you could clearly see the strain on his face as he struggled to continue, even pausing occasionally to rest. It was an incredibly powerful symbol both of the struggle faced by so many people with disabilities as well as the ability to succeed and overcome those struggles through perseverance.

Here's the video on YouTube:

Photo credits: 1) Reuters/David Gray via NYT; 2) Xinhua.

what will happen on september 21st?

In my last post, I described how international media and conversation about Beijing's air largely went silent starting around the second week of the Olympics. However, local conversation here in Beijing has been anything but quiet. If anything, just as foreigners began to lose interest in the seeming non-story of Beijing's lack of air pollution, the local buzz about the improved air quality was just starting to gain momentum.

First, a little background: in August, 2008, Beijing had the cleanest air in 10 years, with the "density of major pollutants cut by 45%" during the month. The data is in and the results (and the air) are clear - the temporary measures to reduce air pollution in Beijing worked.

I remember when the temporary measures were announced back in June, I had mixed reactions. While on the one hand I was personally excited for two months of breathing clean air and riding my bike on gridlock-free streets, as an environmental professional I was disappointed that such temporary policies were needed in the first place. Clearly, the preferred solution would have been the implementation of stringent, permanent air pollution control policies that would have ensured sustainable, Olympics-approved air quality without the need for stop-gap measures. As I contemplated the potential results of the temporary policies, I asked many of my friends and colleagues what they thought would happen on September 21st (the first day after the temporary bans end). At that time (late June), virtually everyone's unanimous response was that Beijing would simply revert back to the same old smog that we had all become used to. In other words, most people I asked thought there would be no long term impacts of the temporary policies.

But I think those of us who have lived in non-polluted cities (please allow me to use the phrase "seen the light," meaning lived in a place where you can't look directly at the sun without burning your eyes, as you often can in Beijing) always held out one great hope: that Beijing's residents and politicians would be inspired; that they would experience life with crystal clear blue skies every day and wouldn't want to go back.

And over the past week or two in Beijing, the most amazing thing has happened: it seems that hope is being fulfilled. Media articles, blog posts, and chat forum polls are filled with discussion on how to keep the air quality this good, with much specific debate on whether or not the odd/even car ban should be made permanent. I'm happy - ecstatic - that these discussions are happening, and that the citizens of Beijing are taking direct interest in and action on air quality. I am even more ecstatic that, so far, the government is open to the opinions and suggestions of the people.

Regarding the permanence of the odd/even car ban, I think it is natural and expected that this should be the focus of the discussion, as this is the single temporary policy that has affected individual citizens the most. However, while I hate to inject any negativity into what I consider to be a wonderful development of citizen environmental activism in China, I feel I must point out that a permanent odd/even car ban may not be the best long term strategy to maintain the air quality we saw over the month of August. For one thing, it is unclear right now how much the air quality improvement can be attributed to the vehicle reduction (as opposed to the factory closures and construction halting). For another thing, as was pointed out on Time's China blog, such a policy could end up having the opposite desired effect, depending on the resulting purchase and use of second cars.

To summarize: hurray for the people in Beijing for demanding that this air quality continue, for the Chinese media for publishing their demands, and for the Chinese government for listening. But let's make sure this energy and drive are directed in the right directions. And what are those right directions? Well, Alex Pasternack has a great start up on Treehugger: 10 Ways Beijing (and Other Cities) Can Keep Its Skies Blue and Road Gridlock-Free.

olympics round-up: impressions of air quality

Photo by Lila Buckley

In the weeks leading up to the Olympics, Beijing's air quality was constantly in the news; questions about whether Beijing would meet its air quality targets, whether events would need to be postponed, and whether the pollution would affect athletes' performances seemed to be the constant refrain of Western conversations about the upcoming Games. In early July, the New York Times cited air quality as one of two primary remaining uncertainties about the preparations.

As the Games approached, these concerns seemed to be entirely validated. Two weeks prior to the Games, Beijing's air pollution exceeded the Olympic standard for four straight days; even the last few days before the opening ceremony were dangerously close to the limit.

Over the first few days of the Games, though, as the API bounced up and down, we began to see mixed reviews about the quality and the impacts. At that time, I predicted a stalemate, imagining that the end result would be the Chinese claiming success with regard to air quality and foreigners grudging that it still wasn't good enough. (Interesting side note here: as I have indicated, the average API during the Olympics was 49; before the Games started, beijingairblog specifically quoted an expert stating that an API of 50 was still "very unhealthy," claiming that only an average API of 25 would be "acceptable for Olympic competition.")

But then, by the second week of the Olympics, a funny - and unexpected - thing happened. The stalemate I predicted never really happened, because Beijing's air quality critics backed down. By August 13th, the New York Times called it "the great air pollution scare," dubbing it "the Y2K computer scare — a nonevent." On the 18th, danwei titled a blog post "Pollution wussies go quiet." Later, DH commented on my blog:

Yo Vance, Gotta tell you that after the start of the games I heard almost NOTHING about air quality from any of the major news sources. Seems like maybe they just decided it wasn't a story anymore. Plus none of the athletes wore those Batman-style gasmasks so there may have been no real "story" to cover...

By the end of the Games, air pollution was a non-issue, eclipsed by so many other stories of the Olympics. Air quality, which seemed so dominant a concern before the Games happened, was barely even mentioned in many of the summary write-ups of the Games that appeared shortly after the closing ceremony. (For example here, here, here, and here.)

However, while Beijing's air quality may no longer be making many headlines abroad, the exact opposite is true here in China. But this is a topic for a separate post...

end of the games

First of all, apologies for the lack of posting this week; I've been busy watching as many events as I can while simultaneously struggling through a wicked cold. With the end of the Games finally upon us, though, I thought I'd fire off some quick numbers on how Beijing did:

First of all, Beijing met its goal of keeping the API below 100 during the Games. Here is the data for the 17 days 8/8/08-8/24/08:


Second, it seems the temporary policies (+ regular rains throughout the Games) worked; let's take a look at some average numbers for comparison:

Average Beijing API during the Olympics, 8/8/08-8/24/08: 49
Average Beijing API since the car ban went into effect, 7/20/08-8/24/08: 64
2007 Yearly Average Beijing API: 101
Average Beijing API during Olympic period 2007, 8/8/07-8/24/07: 86
Average Beijing API during Olympic period 2006, 8/8/06-8/24/06: 76

The average API in Beijing during the 2008 Olympics was 43% lower than the average API in Beijing during the same period in 2007. I'd say that's a pretty dramatic improvement.

More analysis to come.

beautiful in beijing

Yesterday was one of the most beautiful days I've ever seen in Beijing. And the data supports it: the API of 17 yesterday is tied for the lowest on record (going back to June, 2000). Here's the data since the car ban started on 7/20:


As of 8/13, the New York Times was already quoting athletes calling Beijing's pollution concerns "massive hype," and proposing, "it may seem that the great air pollution scare is becoming the equivalent of the Y2K computer scare — a nonevent."

While I appreciate the optimism, I'm not quite willing to go that far at this point; I am still tracking the data carefully and will reserve any sweeping "success" judgments until the end of the Games.

Still, though, I suppose if Beijing can survive the opening ceremony with an API of 94 and the two long distance cycling events at 78 and 82, then the odds are pretty good that we aren't going to see any other dramatically different impressions of the air quality than what we have seen already.

the rift on air quality during the Games

Regarding everyone's favorite Olympic environmental topic, air pollution, it seems like we've reached the stalemate I wondered about at the end of my very first post on this blog. Depending on who you ask, China should either be congratulated for meeting its air quality goals or chastised for allowing athletes to compete in such horrible pollution.

On the one hand, the constant refrain from both the IOC and the Chinese media is that the air poses no risk to the athletes. From Reuters:

The International Olympic Committee (IOC) had warned it might reschedule events if the air quality posed a threat, but on Sunday it said there were no problems.

"The readings that we were looking at indicated that we have no cause for concern at this stage," said IOC spokeswoman Giselle Davis.

On the other hand, we are still seeing many reports with detailed descriptions of how bad it is here. From The Oregonian:

Last weekend, when days were hot, humid and still, the smoggy haze hung thick as a wool blanket. In her blog, [distance runner Kara] Goucher wrote:

"I have to say that the pollution and smog in Beijing is much, much worse than I imagined. It's a bit eerie how the sun never comes out all day. If you are walking around the village and you look ahead, you can't see all of the buildings. The pollution creates a fog that clouds over everything. It is unimaginable. I am shocked by how bad it is."

CNN summarizes, "Despite official assurances that the air is safe for competition, athletes and fans have expressed concern over the thick smog covering the entire city."

However, not everyone is convinced that the air is all that bad. From the New York Times blog:

A handful of track and field athletes worked out on a rainy Sunday morning at the United States Olympic compound at Beijing Normal University, and most said they had not been bothered by the air quality in Beijing. They were adjusting to the humidity, but the pollution, they said, had not been an issue.

This rift - between those who find Beijing's air quality acceptable and those who find it intolerable - that has opened up over the past few weeks is fascinating to me. Perhaps most interesting is that fact that the debate seems to be playing out on so many levels: technical, medical, psychological, political, and more. (I hope to blog in more detail on this topic later.)

In any case, no matter which side you take, at least we finally have some idea of what the air quality is going to be like during the Games. Since 8/8, the API has been up and down. And yet, with the API not "down" enough to make all the foreigners happy and not "up" enough to exceed the Chinese cut-off of 100, the result? Stalemate.

8-8-08

Today is a day to forget about graphs and data and simply to enjoy the spirit, the hope, the optimism, the unity of the Olympics.

I just changed my cell phone ring tone to the Olympic theme music. Needless to say, I am really excited. It is a great day to be here in Beijing!

One World, One Dream!
同一个世界，同一个梦想！

last day before the Games - API at 95

Today's API of 95 is not an encouraging last data point before the Games start tomorrow. I was just up at the Olympic Green and the air there is what my friend describes as "mashed potato air." Beijing API data since the car ban went into effect shown here:


No word yet on whether or not MEP will implement emergency pollution reduction measures. On the contrary, in some respects China doesn't seem all that worried, as evidenced by this article from Xinhua: "IOC: Beijing delivers on environmental promises."

los angeles 1984 olympic air quality

This is the second in a series of posts comparing Beijing's air quality to that of other Olympic host cities. Here, I explore the air quality of Los Angeles during the 1984 Games.

Summary: Lack of available data makes directly comparing the air quality during the Los Angeles Olympics to that of Beijing challenging. The only air quality data I could find for Los Angeles in 1984 are concentrations of ozone and Total Suspended Particles (TSP). Unfortunately, PM10 measurements did not begin in Los Angeles until 1988, and no ozone concentration data is available for Beijing.

Still, some rough comparisons may be made by examining LA's TSP data as well as PM10 data from 1988 on. Here, I conclude the following:

1) Beijing's 2007 annual average PM10 concentration (148 ug/m^3) was approximately twice as high as that in LA in 2007 (76 ug/m^3), and about 1.4 times higher than that in LA in 1988 (104 ug/m^3)
2) Since the car ban went into effect in Beijing on 7/20, the average PM10 concentration has been 111 ug/m^3, 7% higher than LA's 1988 average.
3) Using a rough estimate that PM10 in LA is about 55% of TSP, I estimate the average PM10 concentration in LA during the 1984 Olympics to be around 68 ug/m^3 (corresponding to a Chinese API of 59), more than double the concentration during the Atlanta Games.

Analysis: Again, let's start by examining data sources. The best data source I found was Air Quality Data Statistics from the California Air Resources Board. For an overview, I chose Air Quality Trend Summaries and queried PM10 for the South Coast Air Basin. Unfortunately, the earliest data available in this query is from 1988. Prior to 1988, it seems that the EPA only required the measurement of Total Suspended Particles (TSP), not PM10. The difference between TSP and PM10 is that TSP includes all particles of all sizes, whereas PM10 only includes particles smaller than 10 microns in size. The smaller particles are more damaging to human health because they penetrate deeper into the lungs.

Below is a graph of the available annual PM10 average data for the South Coast Air Basin and Beijing:

It is clear from this graph that Beijing's annual PM10 concentration is still significantly higher than that in Los Angeles, even looking all the way back to 1988.

But, as mentioned in my post on Atlanta, during the Olympics we care less about yearly averages and more about daily averages. And, indeed, the air quality in Beijing recently has been considerably better than the 2007 average. Specifically, the average PM10 concentration in Beijing since 7/20 has been 111 ug/m^3, just 7% higher than LA's 1988 average (104 ug/m^3).

Though PM10 data is not available for LA during the Olympics, it may be worth taking a look at the TSP data to see what we can learn. Summary data for the area is not available prior to 1988, but we can query individual monitoring stations going back to 1983. I chose to query a 10-week period in 1984 starting with July 1. Though there are 12 monitoring sites in Los Angeles, daily data only exists for two stations: Los Angeles - North Main St. and Azusa. This data is shown in the graph below:


During the Olympic period (7/28/84 - 8/12/84), the average TSP concentration at LA - North Main St. was 113 ug/m^3, while the average at Azusa was 136 ug/m^3. I will take an average of these two readings, 124 ug/m^3, as a rough estimate of the TSP concentration in LA during the 1984 Olympics.

Of course, the most obvious question then is: what percentage of the TSP is PM10? I'm not sure the best way to answer this, but I suppose it's reasonable to make a rough approximation by comparing TSP and PM10 data for a time period in which both are available. Towards this goal, I queried TSP and PM10 for the first available year - 1988 - for the Los Angeles - North Main St. station, and compared the TSP to PM10 results for all common data points throughout the year. The result is that on average, the PM10 concentration was 55% of the TSP concentration.

Applying this 55% factor to the Olympic TSP data described above yields an estimated PM10 concentration during the Los Angeles Olympics of around 68 ug/m^3, corresponding to a Chinese API of 59. This result is significantly lower than even the 1988 average, but is consistent with descriptions of considerably improved air quality in LA during the 1984 Games.

Conclusion: Though it is impossible to compare directly the air in Beijing with the air in Los Angeles during the 1984 Olympics, it is clear that, from the perspective of PM10, Beijing's average air is considerably more polluted than that in Los Angeles even in the late 1980's. During the 2008 Olympics, for Beijing's air to be considered equal quality to Los Angeles during the 1984 Olympics, Beijing's API during the Games should average 59 or below.

the mood with just three days left

After seven years of construction and hype, it's hard to believe that the Games will finally be here in just three days. As we go down the home stretch, it's interesting to compare the mood internationally with that here within China.

Internationally, the overarching tone is one of question-filled tension, as if there are all these coiled springs here in Beijing, and everyone is just waiting to see which one is released first. Many Western media articles, as well as my friends and family, simply seem to be wondering out loud, musing on any of a number of topics:

- Will China's temporary environmental measures work?
- What will China's reaction to protests on its own soil be?
- Will the Games be safe and secure, given Beijing's unprecedented focus and expenditure on security? (Side question: is the extreme security justified by the threat, or simply an excuse for the Chinese government to increase surveillance and controls on its own people?)
- What will foreigner visitors think of the "sanitized" Beijing, one in which the taxi drivers speak English, dog is not served on menus, everyone queues properly, and no one spits?

On the whole, with regard to many of these questions, George Vecsey summarizes, "China sought these Games as a major step in its coming-out party, and now China will be tested in front of the world." So now the big question is, will China pass?

Of course, pervading so much of the asking of these questions internationally is an overall pessimistic tone, and sense that China may not pass the test. Over the weekend, one of CNN's home page leading headlines was, "Pollution, Internet, doping dominate Olympics lead-up." Everyone has the coiled springs under a microscope, watching for signs of movement.

In Western conversations, it seems to me that the myriad questions being asked, the anticipation, the anxiety, the sense that any stability is tenuous and any successes short-lived - all of it boils down to the fact that so many see these Olympics as a chance to have a referendum on China as a whole. I think this quote in a recent New York Times letter by Tom Scocca is a good summary:

...the underlying, animating question (or problem): is China fit to host the Summer Olympics? For some segments of the West, it can be answered by a simple syllogism: the Olympics are good. China is bad. China should not host the Olympics.

Like an expandable roller bag, that conclusion can be unzipped to hold whatever ideology you’d like to carry along in it: anti-Communism, democracy, Tibetan independence, press freedom, environmentalism, workers’ rights, Internet openness, Darfur.

Take your pick of the above issues. Each one is all over the news and conversations in the West, and so often accompanied by the simple concluding question, "How will the Olympics affect _____?"

Whereas the mood internationally is dominated by questions of politics and the environment, here in China, as one would expect, the mood is quite different. In my experience, there has been a slow and gradual shifting in mood over the last six or eight months.

At the beginning of this year, there seemed to be a combination of blind optimism and unspecific hope for the Olympics; when I asked my colleague in January what his biggest concern for the Olympics was, he thought for a long time but couldn't think of a single response. Similarly, in this video shot in February and posted on Time's China blog, many Chinese responded to the question of, "What's your biggest hope for 2008" simply with, "That China host the Olympics well," though with few specifics of what defines "well."

From March to May, though, there was a marked shift in China's mood. A series of negative events in China (Tibetan uprising, torch protests internationally, Sichuan earthquake, and others) left many Chinese feeling like victims, and I think suddenly there was a very real sense that perhaps something could go wrong in August as well. Surging nationalism encouraged China to stay strong in the face of such disasters; in May I was invited by a Chinese friend to join a Facebook group called "2008 China Hold On!" whose description reads, in part:

we have been expecting the great Olympics for years, but now when it is coming to us in 3 months, my country and our government are facing unexpected natural disasters and worldwide politcial challenges...

as a local Beijing person, I worried for such situation, while at the same time, i have condifence in our government. i am sure they can overcome all these difficulties and show the world how great and strong China is.

(I declined to join the group.)

Without the ability to predict or control natural disasters, China's fear of failure became more and more specifically focused on the fear of terrorism or vindictive sabotage. The response: increased security.


The impacts of the added security went much further than just inconvenience (three personal impacts: now having to send all bags through an x-ray before boarding the subway, having to show ID every time I enter my work complex, and being frisked three times recently before being allowed to enter a bar). The increased security was accompanied by an increased paranoia on the part of the Chinese that a terrorist attack might occur. In June, I asked all of my colleagues their biggest hope for the upcoming Olympics. In contrast to the responses from similar questions earlier in the year, this time about half of them said their only hope was for a peaceful, safe, and secure Olympics. (The other half hoped that they wouldn't have to work during the Games.) The fear of a terrorist attack or other deliberate disruption seemed acute and widespread. A few colleagues even mentioned leaving Beijing out of fear that it wouldn't be safe to stay here.

But over the last few weeks, it seems to me, the mood here within China has shifted again, this time away from one of paranoia about security and back to one of optimism, pride, and hope. Aided by the Olympic banners and Chinese flags that have gone up all over the city as well as the ever-optimistic state media, I think the mood here is positive, confident, and celebratory that China overcame so many obstacles and is ready, finally, to welcome the world.

I'll conclude with a telling example. Last weekend, at the exact same time that CNN featured the home page headline claiming pollution, censorship, and doping were dominating the Olympics lead-up, China Daily's home page led with the hard-hitting, "Rogge: Beijing Olympic Village is best ever." In light of this, I think a more accurate headline for CNN probably would have been, "Pollution, Internet, doping dominate Western media coverage about Olympics lead-up; China confident and patting themselves on the back."

Photo credits - 1: China Daily; 2: Boston.com, via The Beijinger.

atlanta 1996 olympic air quality

This is the first of what I hope will be several posts over the course of this week exploring historical air quality data from other Olympic cities. I'm starting with Atlanta because that's where I grew up. :)

Summary: Since the car ban went into effect in Beijing on 7/20, the average concentration of PM10 in Beijing's air has been 3.4 times higher than that in Atlanta during the 1996 Olympic Games. During the 1996 Olympics, the overall average concentration of PM10 in Atlanta was 31 ug/m^3. The highest daily average concentration was 51 ug/m^3. These values correspond to a Chinese API of 31 and 51, respectively. Since the car ban went into effect in Beijing on 7/20, Beijing's overall average concentration of PM10 has been 104 ug/m^3, with a daily average high of 186 ug/m^3. These values correspond to a Chinese API of 75 and 118, respectively.

Analysis: To start with, let's examine data sources. The most complete data source I found for historical air quality data in Atlanta was Georgia's Ambient Monitoring Program Database Query for Pollutant Data.

Historical data available for the Atlanta metro area during the Olympic period (7/19/96-8/4/96) includes ozone, SO2, CO, and PM10. (Info on available data is here; for this analysis I looked at the Georgia Tech monitoring station).

Ideally, we would compare all four pollutants to Beijing's current levels. However, since we have no ozone data for Beijing, and PM10 is almost always the highest reported pollutant in Beijing, I focused my analysis for now only on PM10. Depending on time and interest, I may ultimately try to run numbers for CO and SO2, but we'll see.

I queried the Georgia database for PM10 data for various time frames and averaged the results to generate the following table:

(Maxes and mins are from daily averages, not hourly data points.)
(For a description of how to convert PM concentration to Chinese API, see the bottom of this post.)

From this table we can observe the following:

1) During the 1996 Olympics, the overall average concentration of PM10 in Atlanta was 31 ug/m^3. The highest daily concentration was 51 ug/m^3. These values correspond to a Chinese API of 31 and 51, respectively.
2) Atlanta's PM10 concentrations one month before the Olympics were significantly higher than they were during the Games.
3) Atlanta's PM10 concentrations exactly one year after the Olympics were not significantly different than they were during the Games.

The following graph shows the daily average PM10 concentrations for Atlanta during the 17 days of the Olympics:


Now let's compare to Beijing.

First of all, Beijing's 2007 average PM10 concentration was 148 ug/m^3, nearly 5 times Atlanta's average during the 1996 Olympics. (Source: Beijing 2007 Environmental Yearbook, in Chinese).

Since the car ban went into effect on 7/20, I calculate an average PM10 concentration for Beijing of 104 ug/m^3. This is significantly lower than the 2007 average, and is within Beijing's own air quality goal of a PM10 concentration below 150 ug/m^3 (corresponding to an API of 100), but is still about 3.4 times higher than the average concentration in Atlanta during the 1996 Games.

But during the Olympics, we care less about averages, and more about the precise daily results during a specific 17-day period. Since 7/20, Beijing has had a number of days which exceed China's air quality standard, the highest being 7/26, with an average daily PM10 concentration of 186 ug/m^3 (corresponding to an API of 118).

(Source for all Beijing API data is the query function at the bottom of MEP's API page (in Chinese).)

Conclusion: It seems clear that, at least from the perspective of PM10 concentration, Beijing's average air at present is still significantly more polluted than the air was in Atlanta during the 1996 Olympic Games. If Beijing hopes to equal Atlanta's air quality with respect to PM10, Beijing's API during the Games should average 31 or below.

how quickly things can change - API back up to 83

After a beautiful blue sky weekend, the white haze has returned again to Beijing. I spent the entire day outside in the dense, stuffy, heavy air, wondering to myself how anyone could imagine competing in such conditions.

MEP is reporting an API of 83 (though it is days like today that make me long for an independent confirmation of the official data). Here's the updated data since the car ban went into effect on 7/20:


The upturn takes us dangerously close to the limit of 100, and would, it seems to me, make MEP strongly consider moving forward with Plan B. We'll see what happens.

I had wondered if, after the rains of 7/28-7/30 cleared out any residual pollution, we had reached some sort of stable state where the 7/20 bans were finally doing the trick. Apparently I was wrong.

API of 27

With an API of just 27 today, Beijing is GORGEOUS. This is only the third time this year Beijing's API has been below 30.

Data since 7/20:


I think I'm going to go home and go running.

potential emergency pollution reduction policies

The Chinese Ministry of Environmental Protection today released a very detailed list of emergency measures (in Chinese) to be implemented just before the Games start if there is continued concern about meeting air quality targets.

The plan includes further limits on production at factories in and around Beijing, Tianjin, and Hebei, as well as even stricter vehicle restrictions. Under the new plan, in Beijing, in addition to the odd/even car restriction, vehicles whose license plate's last digit matches the last digit of the date would also be banned (though the same exemptions as the odd/even ban would still apply - taxis, emergency vehicles, etc.). Tianjin and Hebei would implement a similar odd/even car ban as Beijing currently has.

The unusually specific document includes exact numbers of factories affected (105 in Beijing, 56 in Tianjin, 61 in Hebei). Reuters has more.

The need for an emergency plan demonstrates a few things:

First, Plan A didn't work. Why didn't it work? To be honest, I'm surprised that it didn't, but I think there is a lot to be learned from the results. One big lesson is simply that Beijing's air quality is affected by a number of complex variables, including pollutant emissions, geography, wind and weather, meaning that it is virtually impossible to predict day-to-day air quality variability, much less the specific impacts of specific control policies.

Second, the WRI's Debbi Seligsohn has a good piece up about how it proves cars aren't the problem, and I think this is a key point. Given that Beijing's primary pollution problem is particulate matter, the majority of which likely stems from factories / construction sites / dust (not vehicles), one would not necessarily expect vehicle restrictions alone to have a large effect. (Though accompanying the 7/20 vehicles ban were parallel factory / construction restrictions.)

Third, as I've mentioned previously on this blog, it shows the Chinese government's complete commitment to meeting its air quality targets, regardless of economic impact. My colleague at lunch was asking who is going to pay these factories for lost production...a question we may never know the answer to.

API of 43

In a dramatic turn-around, today's API is just 43.Take a look at the API data since the car ban went into effect on 7/20:


The dramatic reduction from earlier this week seems clearly the result of light rain yesterday morning, which many people (including some media) are attributing to cloud seeding. I don't doubt this, though neither I nor anyone else I know has a direct source to confirm it.

The four consecutive days (7/24 - 7/27) exceeding the Blue Sky Day limit were putting major pressure on Beijing to deliver some answers about why the temporary environmental measures weren't working, and what they planned to do about it. If the data alone weren't enough, foreign media had a field day taking pictures of Monday morning's extreme haze.

Beijing's three-fold response was as follows:

1) Delay publishing the API data. I don't know if anyone else noticed this, but Monday's API wasn't made available until Tuesday, when both days were reported simultaneously as 96 and 90, respectively. Despite my previous post arguing against the trump card of doubting official data, China is nothing if not a place that makes you question and re-question what you think, and in this case I must say I have a hard time believing Monday's 96 reading.

2) (Presumably) seed clouds, as mentioned previously, to wash away all the particulates in the air.

3) Launch a PR campain calling Monday's event "fog" instead of "haze."

And so the game continues.

air quality targets

Over the last few days, it seems that the hottest topic to report on with respect to the Olympics is air quality, or lack there of, in Beijing. I even gave an interview on NPR last Friday on this very topic. Here, I want to reiterate / clarify / expand on a couple of points I made that were either shortened or edited from the interview.

First of all, I believe strongly that Beijing will meet its air quality targets for the Olympics. Why? Two reasons: first, the Beijing government will keep implementing stricter and stricter policies until they’ve achieved their desired results. (Actually, I think that one reason they started many of the bans on 7/20 was to give themselves enough time to go to Plan B if Plan A didn’t work). Second, I don’t think the Olympic air quality targets are really all that strict.

As far as I can tell, Beijing’s sole Olympic air quality goal / promise is for every day of the Games to be a Blue Sky Day, meaning that the API is less than 100. But Western media seems to be overlooking two key points about this goal. First, the API only considers three pollutants – NO2, SO2, and PM10. Noticeably absent from this list are the two pollutants that athletes seem most concerned about, ozone and PM2.5. Though Beijing monitors ozone and has a national standard, the daily concentrations are not reported publicly. PM2.5 is not even monitored.

Second, a Blue Sky Day in Beijing with an API of 100 could have a PM concentration of 150 ug/m^3. While China still considers this "good" (良) quality air, the US EPA would caution, "Unusually sensitive people should consider reducing prolonged or heavy exertion," calling this air "moderate."

Which leads me to wonder about the following potential scenario: throughout the Games, Beijing celebrates meeting its air quality goals, and yet the international community still complains loudly about the poor air quality. If this happens, who's at fault? Beijing for only meeting its domestic air quality targets instead of WHO targets, or the international community for not demanding more specific, more stringent air quality goals seven years ago?