再问北京蓝天

More than a month after Beijing's manipulation of air-quality data was first exposed, the government's response has been to -- wait for it -- manipulate the data even more. This year to date, record numbers of 'blue sky' days have been reported in the run-up to the August Olympics, thanks mainly to statistical shenanigans. The authorities are getting away with the deception, at least to judge from all the flattering media coverage they're generating.

Beijing notched up 22 blue sky days -- days when reported pollution falls below a certain cut-off -- in January, a new monthly record. It's a widely watched statistic both because Beijing purports to be cleaning up its pollution act and because the government plans to deliver 292 blue sky days this Olympic year. Sure enough, reporters were quick to pick up January's supposed good news, and not just the usual suspects like state-run Xinhua and Beijing-friendly China Daily. Reuters and Britain's Guardian also trumpeted the new pollution data, running this headline earlier this month: 'Beijing sees best run of clear skies since 2000.' Reuters at least noted that China's blue sky standards don't necessarily meet international norms.

But that doesn't mean Beijing's skies are getting any bluer. As I wrote in these pages last month, Beijing achieved stellar results the past few years mainly by moving pollution-measuring stations to less polluted parts of the city, as well as by changing its methodology for measuring pollution. Far from addressing these irregularities, the Beijing Environmental Protection Bureau has upped the ante. Starting from Jan. 1, the government included data from three new collection centers far removed from the polluted hustle and bustle of Beijing.

The three new stations sit in the scenic districts of Huairou, Changping and Shunyi. Huairou lies 60 kilometers to the northeast of the city center, past the second, third, fourth, fifth and sixth ring roads. Changping, 40 kilometers to the northwest, and Shunyi, 40 kilometers to the northeast, are also located beyond the sixth ring road.

These monitoring stations have a track record of producing clean-air results. Huairou reported blue sky pollutant levels in its neighborhood on nearly eight out of 10 days in 2007. Changping and Shunyi reported blue skies on roughly seven out of every 10 days and 6.5 out of every ten days in 2007, respectively, before they were added to the city monitoring network. In contrast, Qianmen, a monitoring station just south of Tiananmen Square, reported a blue sky day on average only once out of every three days in the same period. Qianmen is no longer included in the data collection for Beijing's headline pollution number.

Had the new stations not been included, the number of blue sky days in January would have been the same as in 2005, when 21 blue sky days were reported. Using the pre-2006 station locations, there would have been no more than the 20 blue sky days reported in 2003. An exact comparison with earlier years is no longer possible, because the government has removed stations from the most polluted areas, including Qianmen -- or at least no longer publicly reports the data.

There's nothing inherently wrong with adding new monitoring stations, even though doing so complicates year-to-year comparisons of Beijing's environmental progress. But even if one accepts that the new, more distant stations help build a picture of the metropolitan area as a whole as more people move away from the urban center, the authorities excluded additional reporting stations from the new 2008 list that would better represent what is happening in the air over the city's most developed areas.

For example, a list of monitoring stations prepared in 2006 by the National Environmental Monitoring Center had proposed including stations in the urban districts of Chaoyang, Haidian, and Fengtai for Beijing's blue sky calculations. This would have made more sense if the goal was to report city air quality. However, two of the stations slated to be added reported blue sky days for less than half of 2007, and even the 'best' new station location reported fewer than 60%. Data from these stations were not included in the January 2008 calculation.

Meanwhile, authorities are busily shifting the goal posts in a way that would give any Olympic athlete fits on the playing field. Back in 2004, Shi Hanmin, the director of the Beijing Environmental Protection Bureau, touted the 2008 Olympic target of 80% blue sky days for the city. But last month, the mayor of Beijing announced the new, 'ambitious' target of 70% blue sky days for 2008. Compared with other Chinese cities, the new 70% target is shockingly low. A city with blue skies on 70% of days each year would have languished at the bottom 5% of Chinese cities in the latest rankings by the State Environmental Protection Administration, based on 2006 data. Guangzhou, which has also received recent media attention due to its struggles with air pollution, had over 90% of 2006 classed as blue sky days.

With the new monitoring station locations, Beijing air quality and the number of blue sky days will undoubtedly continue to break records in 2008, garnering even more positive coverage in the national and international media. You'll just have to travel outside of the city to actually see the improvements.

北京操纵空气质量数据一事被曝光已有一个多月了，而政府这期间对此事的态度却是变本加厉──对其进一步操纵。今年截至目前，北京公布的“蓝天”天数已创出新高，主要是因为在统计上做了手脚。不过有关部门却并没有因此成为众矢之的，至少媒体报导使用的还都是些溢美之词。

今年1月份北京的“蓝天”（即各项污染指标均低于某一标准）天数达22天，创造了新的单月纪录。北京宣称要治理污染行为，并计划在今年的奥运年实现292天“蓝天”，空气质量数据因此也受到了各界的广泛关注。毫无疑问，媒体很快就对1月份的“好消息”进行了报导。除了中国官方媒体新华社和《中国日报》(China Daily)外，路透社(Reuters)和英国的《卫报》(Guardian)也对新公布的空气质量数据大加赞扬，本月早些时候还登出这样的头条：“北京蓝天天数创2000年以来新高”。不过，路透社同时指出，中国认定蓝天的标准不一定符合国际标准。

不过，这并不意味着北京的天空变得更蓝了。正如上个月我所写的一样，过去几年里北京公布的空气质量数据都很理想，这主要是因为监测站搬到了污染较轻的地区以及污染评估方法的调整。北京市环保局非但没有纠正这样的违规行为，反而越走越远。自今年1月1日起，政府在空气质量统计中增加了三个监测站的监测数据，而这些监测站都远离城市中心。

这三个新加的监测站位于北京周边的怀柔、昌平和顺义风景区。怀柔监测站位于距离市中心东北60公里的地区，昌平站在西北40公里，而顺义站则位于东北40公里的地区。三个监测站均远在六环之外。

这些监测站都有着良好空气质量的纪录。在被列入北京空气监测网络之前，2007年的监测数据显示，怀柔地区每10天中有近8个“蓝天”，昌平为7天，顺义为6.5天。相比之下，天安门广场南侧的前门监测站同期的数据为每3天中约有1个“蓝天”。如今，北京公布的总体空气质量数据中已经不包括前门站的监测结果了。

如果没有新加进上述三个监测站的数据，今年1月份北京“蓝天”的天数应该和2005年1月份相同，也是21天。如果采用2006年之前所设监测站的数据，2003年1月的“蓝天”天数应该不会超过报导所说的20天。要想与往年数据进行精确比较已经不可能了，因为政府已经把监测站从前门等污染最为严重的地区搬走了──至少是不再对外公布这些地区的监测数据了。

虽然增加这些新的监测站会令衡量北京环境状况的改善程度变得更为复杂，但这一做法本身并无可厚非。鉴于居民不断搬离市中心，人们或许可以接受增加郊区监测站有助反映北京整体空气质量的说法，不过却难以接受监管机构从2008年的监测点中把位于北京最发达地区的监测站剔除了。

举例来说，中国国家环境监测中心(National Environmental Monitoring Center)2006年曾提出一份监测点名单，建议在空气质量统计过程中加入北京市区的朝阳、海淀和丰台的监测数据。如果是为了发布城市空气质量报告，那么这种做法会更加合理。然而，2007年这三个监测站中有两个站点监测到的“蓝天”天数都不足全年的50%，即便是“位置最佳”的那个监测站，其监测到的“蓝天”天数也不到全年的60%。2008年1月份的统计中未收入这些监测站的数据。

与此同时，监管部门却在忙着“调整”空气质量目标，足以令奥运赛场上的任何选手大吃一惊。2004年，北京市环保局局长史捍民曾宣称2008年北京的“蓝天”天数要达到全年的80%。而就在上个月，北京市市长公布了70%这一“颇为艰巨”的新目标。与中国其他城市相比，70%的目标低得令人吃惊。根据国家环保总局公布的2006年城市空气质量排名，每年“蓝天”天数比例为70%的城市在所有受调城市中仅处于最后的5%。最近，广州因空气质量问题也成了媒体关注的对象，可是2006年该市“蓝天”天数已经超过了90%。

增加新的监测站点后，2008年北京的空气质量和“蓝天”天数毫无疑问将不断刷新纪录，国内外媒体对此也会进行更多的正面报导。不过，要想感受北京空气质量的改善，你得去趟北京郊区才行。