The first red alert over air pollution in the Chinese capital almost brought this city to a standstill in December, with schools shut, construction halted and driving restricted. Now, in a swift policy shift, Beijing plans to issue a red alert based on higher thresholds, despite government pledges to better address the toxic air. A red alert, the highest level of a four-tier warning system, will be issued if the daily average air quality index is forecast to exceed 500 for one day, 300 for two days or 200 for four days, Xinhua, the state news agency, reported on Sunday, quoting Beijing’s environmental agency. The new standards will take effect before the end of March, it said. The air quality index, used in many countries, is an aggregate measure of […]