New Delhi, Nov. 1 -- Climate Change and You is a fortnightly newsletter written by Bibek Bhattacharya and Sayantan Bera. Subscribe to the newsletter to get it directly in your inbox.

Dear Reader,

It's that time of the year again. North India is shrouded in a haze, and it's essential to check air pollution levels before going for a walk. It's a persistent problem which hits us year after year. The reasons behind the toxic air are well known. Round the year, it is caused by vehicular pollution, emissions from industries and power plants and biomass burning for cooking. During the winter season, biomass burning for heating and burning of paddy stubble adds to this load.

What happens during the winter is this: since the air close to the so...