美国加利福尼亚州与空气污染细颗粒物的斗争，显然是经济发展与环境保护紧张关系的一次教训。这次斗争是在美国加州环保局的加州空气资源委员会（CARB）与Killcarb.org组织之间展开的。环境加强监管后，管理成本自然上升，受其影响的利益相关者组成了名为Killcarb.org的协会。在中国人眼里，加州是“牛仔领地”，利益相关者之间的争夺异常激烈；而且，公众对抗场面也相当壮观。众所周知，加州前州长阿诺德•施瓦辛格（Arnold Schwarzenegger）是电影明星，其反对党故作姿态，分析时间、能源和资金的耗费，引导观望者痛下决心不再消极而妥协处理各种问题。

排放、监测和控制细颗粒物（PM2.5）的案例是一个极好的例子，其教训恰巧与中国实际相联系，值得中国学习借鉴。科学理论表明，直径小于2.5微米的细颗粒物危害健康。单一的颗粒物就能进入人体、肺甚至血液。虽然裸眼看不见细颗粒物，但它扭曲了光线，因而降低了能见度，我们称之为阴霾或烟雾。PM2.5主要来自发动机（特别是交通）和燃炉（特别是供电和供暖）中的燃烧。仅是一个极微小的2.5微米的颗粒物，很可能由百万亿个原子组成，通常，其中70%是碳原子。

空气中细颗粒物的浓度以毫克/立方米（mcg/M3）为单位。美国环保局（USEPA）提出了一项非常有效的评级体系，将<50界定为好，>300界定为危害大众健康，介于二者的区间范围界定为危害脆弱群体。许多公民认识到可以根据每小时的数据来调整各项活动，例如，当数值高时，避免高强度活动。

然而不幸的是，PM2.5普遍存在和健康的直接关系并不明晰。即使在1952年12月伦敦的大烟雾极端事件中，因此而死亡的人数并不确切，据说是介于4000到12000之间。就峰值，伦敦每天死亡人数的平均值从700（所有原因的正常死亡）增加到900。

加州，特别是洛杉矶和南部山谷流域地区，也曾经发生极端烟雾事件。地形导致自然大气逆温和雾，二战后工业的迅猛发展加重了大气污染，并达到了无法容忍、臭名昭著的地步。加州政府高瞻远瞩，在联邦EPA采取措施之前就着手开始解决该问题。

加州经济充满活力、节节攀升，愿意投入环境保护以维护好莱坞和加州海滩文化所塑造的健康、生气勃发的形象。加州的富人极力支持声名远播的大学和研究所，从而对解决和缓解环境问题充满信心，因为他们能承担解决环境问题所需的费用。此外在加州，公众也愿意以他们的视角加强监督，与商品生产和服务的利益相关者严重对立。

睡着时间的推移，加州空气资源委员会越来越强大。2008年，委员会健康和生态系统部新任命的主任作为一个权力机构官员，作为一项报告主笔人，主张提高标准降低PM2.5排放。该报告评述了一批原创研究项目，并以PM2.5排放和早逝之间关系为题进行二次研究。二次研究并不直接涉及死亡原因的科学原理，但对原创研究中死因和影响的关系进行统计分析。最后，报告建议PM2.5排放标准应从12mcg/M3下降到7 mcg/M3。Killcarb.com协会对标准调整给商业和就业所带来的影响感到悚然，最主要是影响欣欣向荣的卡车运输依赖型商业。大卡车通常是由内燃机发动的，司机是以冒黑色烟雾作为机器正常运作的标志。

2009年的加州，如同1870年的战场。是一场开放战。由于报告统计分析，不是直接的科学，因此容易引起争议，随后炸弹就引爆了。这位主笔人在向所有利益相关者简要介绍后，被指控诈骗。因为他统计学博士学位并不是从他所宣称的加州大学戴维斯分校获得，而是邮购的假学历。加州州长阿诺德•施瓦辛格（Arnold Schwarzenegger）试图为这位主笔人辩护，并指出审稿人是杰出专家。同样不可思议的是，委员会的两名成员明知其博士学历是假的却还为其掩饰，或许是为了实施官僚权力，又或许只是因为他们认为报告本身很不错。

这个问题是许多地球科学辩论的小插曲：在微观层面，科学事实是不容置疑的，但是在宏观层面，我们的地球，对于许多科学问题而言，实在太大，太复杂从而难以圈定到一个单一事实或因素之上。对全球变暖这个问题，各种答案来自统计分析和计算机模型，存在很大程度的主观、预期或潜意识的偏见。加州PM2.5报告的主笔人不诚实到以邮购博士学位证书冒充威名远播（离得很近）的加州大学戴维斯分校的博士学位的弄虚作假，使得所有真实信息都变得可疑。

找到问题的解决方案是件好事。现在，无线电子监测装置现在无所不在，新技术质量不断提高，也降低了成本。除了监视摄像机和监听装置之外，环境监测已经发展出一门崭新学科——生态信息学。中国可以说走在这门学科前沿，2010年在北京召集召开了国际环境信息科学学会会议。

PM2.5的监测现在是项已成熟的可靠技术。美国驻华使馆有一部仪器每小时向互联网和推特（Twitter）发送报告。然而，绘制一幅大型时空图像，之后进行分析，减少事实被简单概念化，是所面临的更严峻的挑战。

艾伦·马克思女士（Ellen Marks）已研究了数十年并坚持积极思考。她为RTI工作，负责中国论题，RTI是美国北卡罗来纳州周边的大学组建的大型研究机构。笔者有幸听她谈论“数据可视化”情况。她将一份难以用简单语言概念化的350页报告用16张图表述出来了。

2009年，美国政府与RTI签约监测180个社区的PM2.5。基于过去10年生态信息学的进展、政务透明化，每个人能看到他们周边地区的三维图。这能帮助他们决定是否外去慢跑和制定慢跑路线，从而避开烟雾。从长远来看，还能影响房地产价值。

地球现在有70亿人口。我们所有人呼吸着相同的空气。然而，空气是流动的也是无形的。地球公民都需要知晓这一点。1661年，英国约翰·伊夫琳（John Evelyn）慷慨激昂地向国王上书请求减轻燃煤造成的阴霾。他提议改良燃料，将污染产业往外迁移“数英里”。250年后，伦敦烟雾事件发生，市民才注意到了伊芙琳的请求。人们将之调侃为“杰文斯悖论”——工业革命提高了技术效率，但这也促进更多的原煤消费，因此，尽管单位燃料排放量下降了，可是总污染排放却增长了。

阿尔·戈尔（Al Gore）通过获奖纪录片《不容忽视的真相》，通俗地解释了温水青蛙的两难境地：如果突然放入热水中，青蛙就会跳起来；但如果逐渐加热，青蛙会尝试着适应新环境也还是死去。在欧洲，虽然污染物已不是问题，然而污染物却导致预期寿命减短了。即使现代有了大型空气过滤器，但人们不可能只呆在家里。因此，温水青蛙的道理我们应该懂得，并积极向公众传播。

直接投资收益理所当然是人类决策和行动的重要动因。过去30年，中国在紧紧跟随西方200年工业革命步伐，但逐渐地，中国意识到了‘‘前车之鉴’’，并努力改善，现在中国拥有先进的清洁技术。这也正是中国戏曲了欧美国家的教训而得来的。

新中国的经历有一些与众不同之处。正当欧洲和美国的议会谴责少数党的领导阶层而陷入困境，在为预算和环境问题争吵不休，中国则拥有一个统一的领导阶层，谋求出类拔萃的政策建议和治理政见。中国在2007年将新的科学发展观写入党章，它将会为走出‘‘烟雾’’指明道路。

The tension between economic development and environmental protection provides an obvious lesson in Californian over the battle concerning fine particulate air pollution. The contest is between the California Air Resources Board (CARB) of USA California Environment Protection Agency and KILLCARB.ORG, the association of stakeholders threatened by higher costs of increased regulation. From the Chinese perspective, California is “cowboy territory” of aggressive contention between stakeholders, and the public confrontations are a spectacle. The participation of the Governor, movie star Arnold Schwarzenegger阿诺·施瓦辛格guarantees public recognition. Analysis of the wasted time, energy and money in the posturing by opposing parties can lead observers to have a greater determination to manage various aspects in a compromising rather than destructive way.

The case of emitting and then monitoring and regulating fine particulate matter (PM2.5) provides and excellent example and give a pertinent lesson for China. Basic science shows that fine particulate matter with a diameter of 2.5 microns or smaller is harmful to health. A single particle can enter the human body and lungs and even blood stream. Figure 1 shows the relative size of a human hair with PM10 pollutants and the even smaller PM2.5. Fine particulate matter is invisible to the naked eye, but distorts light and thus diminishes visibility we call haze or smog. The main sources of PM2.5 are combustion in engines (especially traffic) and furnaces (especially electric power and heating generators). Even a tiny particle of matter 2.5 microns across consists on atoms, perhaps a hundred trillion, and typically about 70% are carbon atoms.

The intensity of fine particulate matter in the air is measured in micrograms per cubic meter. The US EPA provides a useful rating system classing >[WZN1] 50 as good and a scale indicating dangers to vulnerable groups and that <300[WZN2] is hazardous to general population. Many citizens aware of the dangers and of the access to hourly readouts regulate their activities accordingly, for example refraining from strenuous activity if the reading is high.

Yet unfortunately the direct relationship between PM2.5 prevalence and health is not clear. Even in the extreme case of the Great Smog of December 1952 inLondon, the number of people killed is not certain, said to be between 4,000 and 12,000. At the peak, deaths in London rose from an average of 700 per day (normal, from all causes) to 900 per day.

California, and especially Los Angeles and the southern valley basin have also experienced extreme smog. The topography causes natural atmospheric inversion and fogs and the fierce development after WWII exacerbated air pollution to infamous and intolerable levels. The California State Government moved proactively ahead of the Federal EPA to address the problem.

California has had a vibrant progressive economy and was willing to invest in environmental protection to uphold a wholesome healthy image as epitomized by Hollywood and California beach culture. California’s wealth had nurtured prestigious universities and research institutions and thus with confidence were environmental problems addressed and alleviated. They could afford to fix. If this had been China in the 21 century, the stakeholders wanting to directly make money from economic activities and the wider public concerned about environmental downside would not have been allowed or encouraged to voice their disputes to the media or sue each other in court. But in California they did and the momentum of increasing regulation collided as a public spectacle with the stakeholders producing goods and services.

The California Air Resources Board had grown powerful. In 2008 a newly appointed Manager to the Health and Ecosystems Section of CARB clearly was driven by wanting to make a name for himself as a powerful bureaucrat as lead author on a report recommending a lower level for PM2.5 emissions. The report described secondary research on a range of primary research projects into the link between PM2.5 emissions and premature death. The secondary research did not directly deal with the science of death causes, but on statistical analysis to link cause and effect in the primary studies. In conclusion the report recommended that PM2.5 emission standards should be lowered from 12 micrograms/M3 to 7 mcg/M3. The association called KILLCARB.ORG was horrified at the impact this would have on business and jobs, and most especially on the thriving truck transport business. Big trucks are invariably diesel, and the driver and mechanics’ dream is black smoke as a sign of healthy combustion.

In California 2009 this was equivalent to a gunfight 1870. It was open war. Because the analysis was statistical, not straight science, it was easy to argue interpretations and bias. Then the bomb exploded. The lead author, vocal at the briefing to all stakeholders, was accused of fraud. His PhD in statistics was not from UC Davis as claimed, but was a fake mail-order. Incredibly California Governor Arnold Schwarzenegger阿诺·施瓦辛格tried to defend the lead author and cited the eminent peer reviewers. Also incredibly, two of the Board had known the PhD was fake but covered up, maybe to enforce bureaucratic power, or maybe just because they thought the report was good by itself, regardless of the lead author’s credentials.

This problem serves as a vignette for many Earth sciences debates: at the microlevel, scientific fact is unquestionable, but at the macroscale, our Earth is too big and complex for many scientific questions to be pinned down to a single fact or factor. As in the whole question of global warming, the answers are supplied through statistical analysis and computer modeling and are very much open to subjective biases, intended or subconscious. For the lead author of the California PM2.5 report to be insincere to the point of pretending a mail-order doctoral certificate is a genuine PhD from the prestigious (and nearby!) UC Davis puts any verity to question. Given universal human nature, China will also need to contend with similar issues, and the goal, or at least the direction, is to improve science and lessen risks of prejudiced interpretation.

Dynamic Data Visualization

There are some good news solutions becoming available. Electronic wireless monitoring devices are now becoming ubiquitous through new technologies improving qualities and lowering costs. Besides surveillance cameras and listening devices, environmental monitoring has grown into a new discipline of Ecological Informatics. The International Society for Environmental Information Sciences convened in Beijing in 2010 and China is at the forefront of the discipline.

For PM2.5, monitoring is now an established reliable technology. There is one instrument at the US Embassy in Beijing reporting hourly on the Internet and Twitter. The more difficult challenge is in mapping a broad picture in space and time and then analyzing it to reduce the facts to be easily conceptualized.

There is an answer. Ms Ellen Marks has decades of research experience and still thinking forward. She manages China interests for RTI, the giant research triangle of universities around North Carolina, USA. Now based in Beijing it is mesmerizing to hear her talk of “data visualization”. As an example she describes a 350 page report with 16 graphs that is hard to conceptualize in one thought-byte. But new software can grasp a trend in several seconds. For understanding PM2.5, this can be a outstandingly insightful.

Outside your window now, the sky is moving. The hazards in the air can be tracked, real-time. Pressure is being brought to make this knowable. The US government in 2009 contracted RTI to monitor 180 communities for PM2.5. Based on progress in the past decade of ecological informatics, with government transparency, individuals can see 3D graphics of their neighborhood. This can help decide if they will jog or not, and jog away from the smog. In the long run it can influence property values. This technology is coming to China and should be welcomed.

Educating the public

We are now 7 billion people in historically artificial boundaries called “194 nations and territories” according to the UN. We all breathe the same air. The hundreds million in North America and the billions in Asia all share the same air. But air is fluid. It flows. More troublesome, trouble is the air is invisible. Earthlings need to know. In England in 1661 John Evelyn wrote to his king passionately requesting ameliorating the coal-fired haze. He proposed better fuel, and that polluting industries be removed “a few miles”. It was 250 years later after The Great London Smog that the city heeded Evelyn’s plea. One reason for the dalliance was identified as the “Jevons Paradox” – the Industrial Revolution improved technological efficiency but this only encouraged greater consumption of coal, so that total pollution increased even as emissions per unit of fuel decreased.

Al Gore’s award winning documentary, Inconvenient Truth, popularized the dilemma of the frog in hot water: If placed suddenly in hot water it will jump out; but if in water that is comfortable but gradually heated, the frog will try to acclimatize and will die. Educated people should be at the forefront of awareness of emissions. Though there are many important factors in life, including wishing to be in a city for better income and amenities, enjoying decent life expectancy must also be a factor. Even in Europe where pollutions have been assiduously addressed, estimates of reduce life expectancy due to emissions is estimated at least a few months. Promoters of modern large scale airfilters scare customers with gross overestimates of reduced life expectancy, so like the frog in the warming water, it is hard to know when to make a critical decision on changing the environment. Chinese cities are criticized by visitors and now even China Daily (2011:12:6) headlines smog as a severe hazard and quotes the eminent Chinese health experts as identifying PM2.5 as replacing smoking as a top risk factor for lung cancer.

Ignorance on both sides or being smart together

Certainly direct vested interest is a major driver in human decisions and actions. So the environmentally conscious experts in a government institution, even if they have a fake degree like the example above in California, will try to enforce strict regulations for clean living. At the same time the truck drivers, the factory managers and their employees, and similar interests all want jobs and income. Sometimes Westerners sneer at the Chinese Governments quest for “harmonious” resolution of social problems, especially when obvious conflicts of interest are denied or hidden. But China has fast-tracked the West’s 200 years of Industrial Revolution in the past 30 years and is now leading technologies that will make the environment cleaner. Piggybacking the West’s recent advances in monitoring using satellite imagery and field transmitters of data, China will leapfrog some of the mistakes in development in Europe and America.

And there is something else very different in the new China experience. Just as parliaments in Europe and the US are bogged down with blaming and minority leadership, arguing over budgets and environment, China does have a unified leadership seeking the best and brightest policy advice and management. Professor Ma Zhong, Dean of Environment at RenminUniversity is an excellent example of how China will progress. In the new areas in China’s remoter regions, Professor Ma is vocal on not using second hand equipment from old industry, but investing in state of the art renewable energies and green technologies. Old factories on the east coast are scrapped for good. China’s new outlook on scientific development, written into the Constitution in 2007, will lead the way out of the smog.

[WZN1]John, I think you mean no more than 50 mg/m3 is good, right? If it’s true, then it should be < instead. Please clarify here (>50) and next note (<300).

[WZN2]See above.