Women wearing masks to protect themselves from pollutants on Tuesday walked to a subway station on a polluted day in Beijing. The city’s red alerts for smog are as much about duration as they are about severity of pollution forecasts. The forecasting model must predict three or more days of smog with levels of 300 or higher on the city's air quality index, which typically would include having levels of dangerous PM 2.5 particles of about 10 times the safe level.
Women wearing masks to protect themselves from pollutants on Tuesday walked to a subway station on a polluted day in Beijing. The city’s red alerts for smog are as much about duration as they are about severity of pollution forecasts. The forecasting model must predict three or more days of smog with levels of 300 or higher on the city's air quality index, which typically would include having levels of dangerous PM 2.5 particles of about 10 times the safe level. Andy Wong The Associated Press
Women wearing masks to protect themselves from pollutants on Tuesday walked to a subway station on a polluted day in Beijing. The city’s red alerts for smog are as much about duration as they are about severity of pollution forecasts. The forecasting model must predict three or more days of smog with levels of 300 or higher on the city's air quality index, which typically would include having levels of dangerous PM 2.5 particles of about 10 times the safe level. Andy Wong The Associated Press

Lewis Diuguid: Beijing’s red alert air quality warning should set off urgency alarms at U.N. climate change summit in Paris

December 08, 2015 01:34 PM