While global financial markets remain focused on the credit crunch in the US, another market-rattling problem could be brewing thousands of miles away – in China. 

    Many investors expect a post-Olympic economic slowdown in China, as infrastructure spending slows and activities related to the run-up to the games wane. But a pullback could materialise before the Olympics, not after. 

    A pre-Olympic slowdown may be on the cards if the government is forced to act aggressively to reduce pollution in and around Beijing. As any visitor to Beijing quickly realises, air pollution is an acute problem, and one China wants to tackle swiftly, lest its Olympic coming-out party is shrouded in smog.

    Because of the Olympics, China has worked hard to go green. Around Beijing, various polluting industries have either been relocated or refitted with more energy-efficient technologies. Coal-burning plants have been converted to cleaner fuels, and more stringent vehicle emission standards have been instituted. Sizeable funds have been pumped into Beijing's public transport. As a result, the air quality has improved.

    However, doubts persist about China's environment, and for good reason. The challenge before the nation is herculean, considering that China is home to 16 of the world's 20 most polluted cities. As much as 10 per cent of China's farmland is polluted; roughly 700m of China's people drink water contaminated with waste. In 2007, China surpassed the US to become the world's largest emitter of greenhouse gases. 

    In Beijing, soaring car ownership and the lingering presence of many heavy industries are the main causes of air pollution. In addition, Beijing is surrounded by mountains that prevent pollutants from dispersing and is subject to severe sandstorms.

    Against this backdrop, the United Nations has warned that high levels of air pollution are a “legitimate concern” for anyone participating in the games. The International Olympic Committee has also expressed its concerns and has said that some events may have to be rescheduled. Haile Gebrselassie, the men's marathon world record holder, is threatening not to run if conditions are not safe. All of the above has not been lost on Chinese officials. According to Bloomberg, the government has already decided to close several coal-fired power plants, cement factories and chemical manufacturers about a month before the games. 

    Similarly, factories producing steel, building materials and other pollution-generating commodities may be shut down or have their production limited prior to the Olympics. Also, the government is expected to ban more than 1m cars from the capital's streets before and during the games. Construction activity is expected to be curbed sooner rather than later.

    To what extent these measures slow the pace of real growth in Beijing in particular and China in general remains uncertain. Yet there is little doubt that should the government mandate a two- or three-month, pre-Olympic reduction in industrial output, the general economy will feel some of the pain. The macro impact would not be insignificant, since Beijing and China's north-east account for about 30 per cent of the nation's industrial production.

    In the end, the more China struggles to improve its environment, the greater the potential for more draconian measures. The games are too symbolic for China not to act aggressively. Hence, if the air does not start to improve by the spring, China may have no choice but to slam on the industrial brakes.

    Such a scenario would stun a global financial community long-accustomed to China growing by 10 per cent or more a year. In particular, a pre-Olympic slowdown could result in a deflationary shock to the global commodity markets, triggering an abrupt decline in commodity prices. In turn, real growth in many high-flying commodity nations would weaken. The upshot: weaker global growth and softer global earnings in 2008.

    All of the above is another way of saying that there is a great deal riding on China and its battle to clean the air before this August.

    The writer is chief market strategist at Bank of America 

    盡管全球金融市場仍在關注美國的信貸危機，但在數千英里外的中國，另一個令市場不安的問題可能正在醞釀之中。

    許多投資者預計，在奧運會之后，隨著基礎設施支出放緩，奧運會相關活動退潮，中國的經濟增長將會減速。但是，這種減速可能在奧運會之前就會成為現實，而非在奧運會之后。

    如果中國政府被迫采取激進手段，減少北京及周邊地區的污染，那么奧運之前的經濟減速就會成為可能。任何前往北京的人都會很快意識到，空氣污染是一個嚴重問題，也是中國希望迅速解決的問題，以免奧運會的開幕式籠罩在霧靄之中。

    由于奧運會，中國已采取了大量環保措施。在北京周邊，各類污染企業要么已經搬遷，要么進行了技術改造，改用能效更高的技術。燃煤工廠已轉向更清潔的燃料，更嚴格的汽車排放標準也已經制定出來。政府還向北京的公共交通投入了大量資金。這些措施的結果是，北京的空氣質量已有所改善。

    不過，人們仍然對中國的環境持懷疑態度，而且理由充分。鑒于在全球20個污染最嚴重的城市中，中國就占了16個，因此中國面臨的挑戰非常巨大。中國多達10%的農田被污染；大約7億中國人的飲用水中含有污物。2007年，中國取代美國成為全球最大的溫室氣體排放國。

    在北京，汽車保有量不斷飆升，許多重工業企業遲遲沒有搬遷，成為空氣污染的主要原因。此外，北京四周環山，不利于污染物的擴散，并且北京遭遇嚴重的沙塵暴襲擊。

    在這種背景下，聯合國已經發出警告，對任何參加奧運賽事的人來說，嚴重的空氣污染都是一個“合理的擔憂”。國際奧委會(International Olympic Committee)也表達了自己的擔憂，并且表示，一些賽事可能不得不改期。男子馬拉松項目世界紀錄保持者海利•蓋布雷塞拉西(Haile Gebrselassie)威脅稱，如果環境不安全，他將拒絕參賽。中國官員注意到了上述所有情況。據彭博(Bloomberg)報道，中國政府已經決定，在奧運會前一個月左右，將關閉數家燃煤發電廠、水泥廠和化工廠。

    同樣，在奧運會前，鋼鐵、建筑材料以及其它致污大宗商品制造廠可能也將關閉或是限產。此外，在奧運會舉辦之前和期間，預計中國政府將限制逾100萬輛汽車駛上首都街道。預計建筑活動受到限制的時間只會提早，而不是推遲。

    這些措施將在多大程度上放緩北京乃至整個中國的實際增長步伐，目前仍不能確定。不過，幾乎沒有人懷疑，如果中國政府要求在奧運會前減少兩三個月的工業產出，整體經濟將會受到一定程度的影響。宏觀影響可能不容忽視，因為北京和中國東北地區的工業產出約占全國總產出的30%。

    總而言之，中國越是努力改善環境，實施更嚴厲措施的幾率就越大。奧運會的象征意義之高，讓中國不得不積極采取行動。因此，如果到今年春季，空氣質量還沒有開始改善，中國或許將別無選擇，只能對工業猛踩剎車。

    對于長期以來已習慣于中國年增長率在10%以上的全球金融市場來說，這種情形可能會讓它們目瞪口呆。特別是，奧運會前的中國經濟增速放緩，可能對全球大宗商品市場形成通縮沖擊，引發大宗商品價格突然下跌。進而，許多大宗商品生產國的實際增長可能走軟。其結果是：2008年全球增長走弱，全球業績走軟。

    上述種種情況從另一個側面表明，有很多因素依賴于中國以及中國在今年8月份前凈化空氣的努力。