Images of farmers burning crop stubble in India’s northern Punjab state. This practice is one of the key drivers of Delhi's annual smog problem, worsening the impact of vehicle and industrial emissions. It persists despite efforts to persuade farmers to use different clearing methods and threats of punitive action for those who defy burning bans. Eye-stinging and lung-burning smog peaks from October to February when colder air traps pollution, with residents advised to wear face masks outside at all times. IMAGES OF FARMERS BURNING CROP STUBBLE IN INDIA