(01 of17)
Open Image ModalA little tourist wearing the PM2.5 mask walk on the Tiananmen Square during severe pollution on January 31, 2013 in Beijing, China. (Photo by Feng Li/Getty Images) (credit:Getty Images)
(02 of17)
Open Image ModalTraffic moves along a street as pedestrians walk on an overpass shrouded in haze in Beijing, China, on Friday, March 15, 2013. China\'s new premier promised to crack down on corruption and clean up pollution, acknowledging the need to tackle two issues that have stoked public anger toward the country\'s leaders. (credit:Tomohiro Ohsumi / Bloomberg / Getty Images)
(03 of17)
Open Image ModalTraffic moves along a street as pedestrians walk on an overpass shrouded in haze in Beijing, China, on Friday, March 15, 2013. China\'s new premier promised to crack down on corruption and clean up pollution, acknowledging the need to tackle two issues that have stoked public anger toward the country\'s leaders. (credit:Tomohiro Ohsumi / Bloomberg / Getty Images)
(04 of17)
Open Image ModalHaze surrounds the International Commerce Centre (ICC) in the West Kowloon district of Hong Kong, China, on Monday, April 15, 2013. Hong Kong\'s air pollution index reached the \"severe\" level for the third time this year, triggering a government warning, as the lack of air flow trapped pollutants in the city. (credit:Jerome Favre / Bloomberg / Getty Images)
(05 of17)
Open Image ModalDiesel fumes come out of a tug boat chimney as skyscrapers stand in the Wanchai district of Hong Kong, China, on Monday, April 15, 2013. Hong Kong\'s air pollution index reached the \"severe\" level for the third time this year, triggering a government warning, as the lack of air flow trapped pollutants in the city. (credit:Jerome Favre / Bloomberg / Getty Images)
(06 of17)
Open Image ModalA man wears a mask as he walks down a street in Beijing, China, on Friday, March 15, 2013. China\'s new premier promised to crack down on corruption and clean up pollution, acknowledging the need to tackle two issues that have stoked public anger toward the country\'s leaders. (credit:Tomohiro Ohsumi / Bloomberg / Getty Images)
(07 of17)
Open Image ModalTraffic moves along a street shrouded in haze in Beijing, China, on Friday, March 15, 2013. China\'s new premier promised to crack down on corruption and clean up pollution, acknowledging the need to tackle two issues that have stoked public anger toward the country\'s leaders. (credit:Tomohiro Ohsumi / Bloomberg / Getty Images)
(08 of17)
Open Image ModalA woman wears a mask as she walks on a street in Beijing, China, on Friday, March 15, 2013. China\'s new premier promised to crack down on corruption and clean up pollution, acknowledging the need to tackle two issues that have stoked public anger toward the country\'s leaders. (credit:Tomohiro Ohsumi / Bloomberg / Getty Images)
(09 of17)
Open Image ModalThis picture taken on January 29, 2013 shows a general view of buildings in the heavy smog in Jilin, northeast China\'s Jilin province. Beijing urged residents to stay indoors on January 30 as emergency measures were rolled out aimed at countering a heavy cloud of smog blanketing the Chinese capital and swathes of the country. (STR/AFP/Getty Images) (credit:Getty Images)
(10 of17)
Open Image ModalChinese tourists look at the view from the historic Jingshan Park as smog continues to shroud Beijing on January 31, 2013. (MARK RALSTON/AFP/Getty Images) (credit:Getty Images)
(11 of17)
Open Image ModalTwo Chinese policemen guard in front of two LED screens on the Tiananmen Square during severe pollution on January 31, 2013 in Beijing, China. (Photo by Feng Li/Getty Images) (credit:Getty Images)
(12 of17)
Open Image ModalA general view shows the Guotai Chambers building from the historic Jingshan Park as smog continues to shroud Beijing on January 31, 2013. (MARK RALSTON/AFP/Getty Images) (credit:Getty Images)
(13 of17)
Open Image ModalA Chinese tourist takes photos from the historic Jingshan Park as smog continues to shroud Beijing on January 31, 2013. (MARK RALSTON/AFP/Getty Images) (credit:Getty Images)
(14 of17)
Open Image ModalChinese tourists looks at the view from the historic Jingshan Park as smog continues to shroud Beijing on January 31, 2013. (MARK RALSTON/AFP/Getty Images) (credit:Getty Images)
(15 of17)
Open Image ModalTourists visit the Tiananmen Square during severe pollution on January 31, 2013 in Beijing, China. (Photo by Feng Li/Getty Images) (credit:Getty Images)
(16 of17)
Open Image ModalA little tourist wearing a panda mask walk on the Tiananmen Square during severe pollution on January 31, 2013 in Beijing, China. (Photo by Feng Li/Getty Images) (credit:Getty Images)
(17 of17)
Open Image ModalThe little tourists play on the ground with frozen ice at the Tiananmen Square during severe pollution on January 31, 2013 in Beijing, China. (Photo by Feng Li/Getty Images) (credit:Getty Images)