Burning of agricultural waste in Punjab, especially paddy stubble, is a major seasonal source of air pollution in the NCR (and to a much greater extent in Punjab) in the winter months. Travelling through Punjab in November is like moving through dense fog, with very low visibility. It is estimated that every year over a million hectares of paddy stubble are torched in Punjab. This releases approximately 12 megatons of carbon dioxide into the atmosphere. NASA has been tracking this phenomenon and its satellite images show large chunks of Punjab to be on fire.
Air pollution has broader geographic ramifications because it respects no boundaries. It is a severe health hazard, causing respiratory problems and allergies. It also reduces visibility on the roads, resulting in traffic accidents and loss of life.