But first, India is the world's third largest emitter of greenhouse gases, that's third largest measured by total emissions not per capita emissions. Under pressure ahead of a big environmental conference in Paris at the end of the year the government in New Delhi's now formally pledged to reduce the intensity of its emissions by up to 35% by 2030. This is not a cap on emissions. A cut in intensity's measured against GDP which means that if growth continues, as the Modi government certainly hopes it will, total emissions will inevitably continue to rise.

As part of that balanced emphasis, India says it'll generate 40% of its electricity from non-fossil fuel sources, mainly solar and wind. I asked Sanjay Vashist who's director of an NGO called Climate Action Network South Asia - he's based in Delhi - whether the government's made a credible case for a greener future.

They are making a credible case because there is already an aim to increase renewable energy by 175 gigawatt by 2024. And if that happens, then the public-sector investments will be very much into renewable energy. There'll be institutional systems in place. There'll be infrastructure in place. And by then it will make certainly a good business case of adding more renewable energy rather than adding nuclear in large title.