Stubble burning every winter is a major contributor to New Delhi being one of the world's most polluted cities, with the smoke combining with vehicle exhaust, dust and remaining trapped in atmosphere.

India has seen a dramatic boom in renewable energy installations - but that's not been enough to supply increasing power needs, prompting the government to also double down on coal power

About three-quarters of the coal-fired generators near major cities are set to miss a year-end deadline to install equipment to curb sulfur-dioxide emissions