The China Meteorological Administration of the Chinese Academy of Social Sciences published a green paper on climate change on November 4. It reveals that 30 to 40 percent of Beijing's PM2.5 pollution comes from surrounding regions, the Beijing Daily reported.

Song Lianchun, director of the National Climate Center, said there have been 49 hazy days during 2013 in the Beijing-Tianjin-Hebei region and that PM2.5 levels were excessive on 79 days. The increase is attributable to higher energy consumption, airborne dust and general atmospheric circulation. The green paper also mentions that haze may jeopardize respiratory and immune system functioning as well as reproductive health.