India has been viewed by many, in my view unfairly, as an obstacle to progress. Now is the time for India to move into the lead on international discussions. The world has only just over four months to find an agreement in Copenhagen in December 2009. India's role will be vital. There is no more important issue for the well-being of future generations in India and the rest of the world. If Indian emissions were to peak at around five tonnes per capita in 2030 and China's around nine tonnes per capita in 2020, as part of successful global action, historians, looking back in 2050 would have to regard India as a hero.

Their emissions, on the road to overcoming poverty would have peaked at five tonnes per capita, compared with China at nine, Europe at 12, and the US at well over 20. This illustrates the consequences of past action by the rich countries in "filling up" the atmosphere and China's growth surge starting a decade or two before India's. Unfortunately, unless India is a hero in this sense, it will not be possible for the overall targets to be realised. We start in a very difficult and inequitable position.

This perspective surely underlines India's moral authority. It demonstrates that India is uniquely qualified to take a lead in framing the agreement. It shows how wrong it is to accuse, as some do, India of intransigence. And it establishes that India has a very powerful case for substantial technological and financial support for its move to low-carbon growth. The argument is not, however, only about the worthiness of India's moral position, its potential leadership and the future safety of the planet.

India has much to gain beyond the crucial issue of greater security from climate change. Low-carbon growth is likely to be more energy-secure, cleaner, quieter, safer and more bio-diverse. The transition over the next two or three decades is likely to bring a period of dynamic innovation and investment which could drive strong growth, just as the railways and electricity did in earlier periods. If India now takes the lead in these discussions of climate change, along the lines I have tried to describe, it will have transformed the future prospects of our planet. It will also have placed itself where it should be – at centre stage.

Lord Stern was delivering at the Jawaharlal Nehru Memorial Lecture hosted by Chatham House last week