Pollution in China

Beijing authorities cancelled hundreds of flights and shut highways as thick smog descended on the Chinese capital on December 4 and 5, reducing visibility at one of the world’s busiest airports. Air quality in Beijing reached “hazardous” levels on December 5, according to the US embassy, which conducts its own measurements, while China’s state Xinhua news agency said pollution was likely to reach “dangerous” levels.

Airplanes queue to take off while shrouded in smog at Beijing International Airport on December 5, 2011. Beijing authorities cancelled hundreds of flights and shut highways as thick smog descended on the Chinese capital on December 4 and 5, reducing visibility at one of the world’s busiest airports. Air quality in Beijing reached “hazardous” levels on December 5, according to the US embassy, which conducts its own measurements, while China’s state Xinhua news agency said pollution was likely to reach “dangerous” levels. (LIU JIN/AFP/Getty Images)

Cars pass along a road in thick smog in Beijing on February 21, 2011. Beijing went “beyond” measurable pollution levels, the US embassy said, as a Chinese official warned people to stay indoors and avoid outdoor activities. Air pollution in Beijing has been consistently listed as among the worst in the world by international organizations such as the United Nations. (GOH CHAI HIN/AFP/Getty Images)

A child plays on an iPad as travelers wait for their flights delayed due to smog at Beijing International Airport on December 5, 2011. (LIU JIN/AFP/Getty Images)

Chinese people pass through the rail after a snowfall with heavy pollution on December 2, 2011 in Beijing, China. The Chinese capital embraced its first snowfall in winter. (Photo by Feng Li/Getty Images)

In a picture taken on September 14, 2011 Chinese environmental activist Wu Lihong checks the water quality in an irrigation channel outside a chemical factory beside a rice paddy and on the edge of Taihu Lake in Yixing in Jiangsu Province. Prominent environmental activist Wu Lihong plunges his hands into a thick layer of toxic green scum and brown foam floating on one of China’s biggest freshwater lakes. Despite a two-decade battle to clean up the once-scenic Taihu Lake that earned him three years in jail, Wu says the water still “stinks” from pollution. (MARK RALSTON/AFP/Getty Images)

Photo taken on January 19, 2011 shows heavy smoke after an explosion ripped through an oil refinery in Fushun, northeast China’s Liaoning province. The blast shattered the windows of buildings 100 meters away and ignited a blaze later brought under control by firefighters, which left more than 30 people injured. No deaths were reported at the facility owned by a subsidiary of China National Petroleum Corporation. (STR/AFP/Getty Images)

Chinese children swim along the algae-filled coastline of Qingdao, in eastern China’s Shandong province on July 17, 2011. Green algae continues to spread in waters off China’s east coastline and although not poisonous, it can hinder the fishing industry and tourism in affected areas. (STR/AFP/Getty Images)

Sunshine is filtered through particularist, as seen from Kowloon Peak, hanging over Hong Kong on February 6, 2011. According to the Environmental Protection Department (EPD) the pollution in Hong Kong ranged from medium to very high, with the pollutants such as respirable suspended particulates, nitrogen dioxide and ozone affecting the air quality. (ANTONY DICKSON/AFP/Getty Images)

A woman wears a mask as she makes her way along a street in thick smog in Beijing on February 21, 2011. Beijing went “beyond” measurable pollution levels, the US embassy said, as a Chinese official warned people to stay indoors and avoid outdoor activities. Air pollution in Beijing has been consistently listed as among the worst in the world by international organizations such as the United Nations. (GOH CHAI HIN/AFP/Getty Images)

People walk along a street in thick smog in Beijing on February 21, 2011. Beijing went “beyond” measurable pollution levels, the US embassy said, as a Chinese official warned people to stay indoors and avoid outdoor activities. (GOH CHAI HIN/AFP/Getty Images)

This photo taken on March 2, 2011 shows waste materials strewn all over a rubbish dump near a construction site in a suburb of Beijing. China, the world’s biggest polluter, plans to “go green” in the next five years, emphasizing energy efficiency and the battle on its choking pollution in its plans to revamp the economy, experts say. (GOU YIGE/AFP/Getty Images)

Algae floats in the Hanjiang river, a tributary of the Yangtze River in Wuhan after rain-triggered floods, in central China’s Hubei province on June 20, 2011. Flood-hit areas of central and southern China braced for more heavy rains after millions of people were forced to evacuate or were otherwise affected by the early onset of the rainy season. (STR/AFP/Getty Images)

A picture taken on March 2, 2011 shows discarded medical pills strewn over a rubbish dump in a suburb of Beijing. China, the world’s biggest polluter, plans to “go green” in the next five years, emphasizing energy efficiency and the battle on its choking pollution in its plans to revamp the economy, experts say. (GOU YIGE/AFP/Getty Images)

Local residents fish in a polluted river in Beijing on March 29, 2011. China will aim to reduce both carbon intensity and energy consumption per unit of GDP by about 3.5 percent in 2011 compared with last year, the National Development and Reform Commission, the top economic planning agency, said in a separate report. (LIU JIN/AFP/Getty Images)

This photo taken on June 13, 2011 shows a Chinese boy running along the rubbish-strewn beach along the sea coast in Anquan village, south China’s Hainan province. China suffers from widespread water pollution after years of unbridled economic growth. According to government data, more than 200 million Chinese currently do not have access to safe drinking water. (STR/AFP/Getty Images)

A near deserted Tiananmen Square is pictured in Beijing on October 22, 2011, as thick fog covers the city for days. Heavy fog mixed with pollution was expected to smother the capital city for another few days, as thousands of domestic and international visitors arrive daily during the peak autumn tourism season. (Photo credit should read STR/AFP/Getty Images)

This general view shows a thick cover of fog in Beijing on October 22, 2011. Heavy fog mixed with pollution was expected to smother the capital city for another few days, as thousands of domestic and international visitors arrive daily during the peak autumn tourism season. (Photo credit should read STR/AFP/Getty Images)

A picture taken on September 14, 2011 shows algae fouling the water of Taihu Lake in Yixing in Jiangsu Province. Prominent environmental activist Wu Lihong plunges his hands into a thick layer of toxic green scum and brown foam floating on one of China’s biggest freshwater lakes. Despite a two-decade battle to clean up the once-scenic Taihu Lake that earned him three years in jail, Wu says the water still “stinks” from pollution. (MARK RALSTON/AFP/Getty Images)

A woman wears a mask as she rides a bicycle in Beijing on October 31, 2011. (PETER PARKS/AFP/Getty Images)

A man walks through heavy pollution on a street in Beijing on November 1, 2011. (PETER PARKS/AFP/Getty Images)

Cars drive on the Second Ring road in Beijing on November 22, 2011. Several Chinese celebrities have recently joined an online campaign aimed at pressuring the government into improving the way it measures air pollution, as residents increasingly worry about their health. The campaign comes as locals in Beijing, one of the world’s most polluted cities have started to question a discrepancy between US embassy readings of air pollution in the capital and official data that is often milder. (Photo credit should read MARK RALSTON/AFP/Getty Images)

An elderly couple wears masks as protection against air pollution in Beijing on November 22, 2011. (MARK RALSTON/AFP/Getty Images)

A Chinese motorist wears a mask as she makes her way along a smog filled road in Hefei, east China’s Anhui province on November 29, 2011. The amount of global warming gases sent into the atmosphere made an unprecedented jump in 2010, according to the US Department of Energy’s latest world data on carbon dioxide emissions, with China alone was the biggest polluter with a spike of 212 million metric tons in 2010 over 2009. (STR/AFP/Getty Images)

Chinese motorists make their way along a smog filled road in Hefei, east China’s Anhui province on November 29, 2011. (STR/AFP/Getty Images)

Cars travel on the second ring road as pollution reaches what the US Embassy monitoring station says are “Hazardous” levels in Beijing on December 5, 2011. Officially, Beijing’s air quality is improving but in recent weeks patients with respiratory problems have flooded hospitals, highways have closed and hundreds of flights have been grounded by thick smog. Concerns are being fueled in part by data gathered by the US embassy in Beijing, which produces its own pollution readings using a different gauge to Chinese authorities and broadcasts them online and on Twitter. (MARK RALSTON/AFP/Getty Images)

A truck containing used plastic bottles travels along a highway covered in haze in Beijing on December 5, 2011. (LIU JIN/AFP/Getty Images)

Cars pass through toll booths on a highway covered in haze in Beijing on December 5, 2011. (LIU JIN/AFP/Getty Images)