For now, the Intergovernmental Panel on Climate Change has some information on India-specific impacts: There would be increase in rainfall by 15-40 per cent by the end of the 21st century with high regional variability. The mean temperature would increase by three to six degrees by the end of the 21st century.

The policy makers want to know specifically how much water would be available in the Himalayan rivers in the next 50 years. Also, which areas of the country would be worst affected by extreme weather. Apart from helping decide its own policies to combat these effects, some of this information is vital for leveraging international funds for adaptation. Exact information would help build a case for India in international climate change negotiations--it would illustrate how some parts of the country are vulnerable.

“China is one country that is light years ahead of us in modelling capabilities,” said R K Pachauri, chairman, IPCC, making a case for ramping up India’s computing facilities. China has already come up with its domestic roadmap for adapting to climate change.

Experts agree that understanding and predicting earth’s climate system, particularly climate variation, presents one of the most difficult challenges in science. According to the council, a supercomputer could help shed light on this debate.