Time Magazine: That soupy brown air is the result of so-called black carbon expelled into the atmosphere in and around the Indian capital, from the burning of biomass for cookstoves and of black coal for electricity, and the incomplete combustion in the old diesel engines that propel most of the cars and trucks in the city. Breathing here isn’t all that good for you — there’s a reason the city is home to the "Delhi cough" — and now scientists are discovering that the sooty air isn’t good for the climate …