No cookie-cutter fixes on air pollution
A Nobel Prize-winning chemist who identified the cause of the atmospheric ozone hole has called for new studies into air pollution in the world’s megacities, arguing that differing local conditions mean the world cannot rely on cookie-cutter solutions created in highly developed cities like Los Angeles and London. Mario Molina, who in the 1970s identified chlorofluorocarbons, widely used as refrigerants, as a threat to atmospheric ozone, used examples of efforts to curb pollution in Mexico City and Beijing to highlight his contention that new knowledge and fresh policy solutions are needed to address the thick, sickening smog that obscures the urban air there. In Beijing, Molina said, steps to reduce sulfur dioxide have been successful in cutting levels of the pollutant, but not in clearing the air. The reason, he said, has been highlighted by laboratory studies that show that, in addition to sulfur dioxide, nitrogen oxides and ammonia are precursor chemicals...