On 23rd January the Beijing Municipal Environmental Monitoring Centre began to release atmospheric pollution data online (see this site but a knowledge of Chinese helps in navigating and understanding the data http://translate.google.co.uk/translate?hl=en&sl=zh-CN&u=http://zx.bjmemc.com.cn/&ei=EBVjT5LAIKXS0QWE-JT1AQ&sa=X&oi=translate&ct=result&resnum=5&ved=0CH4Q7gEwBA&prev=/search%3Fq%3DBeijing%2BMunicipal%2BEnvironmental%2BMonitoring%2BCenter%26hl%3Den%26biw%3D1707%26bih%3D1121%26prmd%3Dimvns ).
The hourly data had previously only been available for laboratory use (http://www.china.org.cn/environment/2012-01/06/content_24337033.htm) but the release of the data seems to be a response to public concern over air quality and the mismatch between government statistics and public perception of air quality. Some of this perception may have resulted from the release of atmospheric pollution data by the US Embassy from a rooftop monitoring station(http://ecocentric.blogs.time.com/2012/01/22/political-pollution-how-bad-air-equals-social-unrest-in-china/ for report and http://www.nytimes.com/2011/12/07/world/asia/beijing-journal-anger-grows-over-air-pollution-in-china.html?_r=1 for a discussion of the halting of the tweets in July 2009 and http://twitter.com/#!/beijingair for the tweet). The mismatch between official announcements about good quality air and the tweet caused some friction between officials and the embassy.
So what are we to make of the release of this data? Firstly, it is handy to know Chinese to interpret the site but then again the site is not aimed at an English speaking foreigner but at the Chinese inhabitants of Beijing so this is a fairly lame criticism. Secondly, the data release may be a political decision but at least the data is out there and can now be assessed by the public and by other scientists around the world working on air pollution – surely a good thing in its own right. Thirdly, should the data be questioned? The US embassy site seems to have taken on the role of arbitrator in assessing the data quality (at least in Western press releases). The US embassy is just one site with monitoring equipment at a specific height (not necessarily standardized to the height of the Chinese monitoring stations) so any spatial variation in air quality would not be picked up by data from one site. Even asking the question about data reliability is political. It suggests that the Chinese data will somehow be affected by the political powers that be (as if the US act of monitoring pollution isn’t political as well?!) Details of where the monitoring sites are located, the accuracy and standardization of the monitoring equipment, etc are reasonable scientific questions to ask both of Chinese pollution data and the pollution data of any monitoring network wherever it is. Such questioning ensures comparability of datasets. By releasing the data the Chinese scientists and authorities are putting themselves within this scientific debate. Criticising a dataset does not mean the data set is wrong; questioning and clarification and refinement to ensure compatibility is merely part of the scientific process.