In the hilly Singrauli region of northern India, animals feed on ash-covered grass, smoke stings the eyes and burns the throat, and the reservoir is foul with toxins such as mercury and arsenic. Even the breakfast eggs are grey.

The critically polluted landscape was once forest and fields of grain and mustard flowers. But after four decades of industrial development, this is India's power hub. More than a dozen coal mines and power plants spread over two states generate a fifth of the country's electric power. The region is a key driver of India's greenhouse-gas emissions, the third-highest in the world for a single country.

Coal production is slated to expand here in the coming months, part of the new government's ambitious push to double India's output to more than 1 billion tons annually to meet the needs of a burgeoning economy - with growth now set to outpace China's, according to several forecasts.