Reading in her hotel room in 1996, geology student Cao Jing noticed something alarming: the pages of her book were being coated with brown coal dust.
Her realization -- in Qinhuangdao, a tourist city where China’s Great Wall meets the sea -- marks the moment when the young undergraduate at Beijing’s Peking University became interested in studying the effects of China’s runaway industrial pollution. It was the first step in a 17-year journey that has taken Cao, 36, into the field of economics to tackle emissions in the world’s biggest producer of greenhouse gases.