New Delhi: India is "completely unprepared" to cope with widespread flooding and drought in the country as a consequences of global warming leading environmentalist, R K Pachauri, chairman of the inter-government panel on climate change and director-general of the Energy Research Institute, has warned.

"India has to implement adaptative measures to deal with the rising sea level, more intense-tropical storms and other threats to the eco-system," he said.

Pachauri pointed out to the urgent need for a range of measures including limiting new buildings along threatened coastlines, building forest corridors to allow threatened species to migrate and improving water conservation to cope with the threat.

More than 60 per cent of India''s nearly 1.1 billion people depend on agriculture for survival and climate change will drastically reduce crop production in the country, he said adding, "but we are yet to adopt adaptation measures".

Not only crop production would be reduced, but vast areas where food could be grown will also shrink, affecting the quantity, he said.

According to Pachauri, global warming would result in substantial decrease in cereal production in Asia, as a 0.5 per cent rise in winter temperatures would reduce wheat yield by 0.45 tonnes per hectare in India.

Climate change was also likely to heavily impact coral reefs, fisheries and other marine resources of small islands of the Pacific Ocean, Pachauri said adding there was likely to be a decline in the total tuna stocks and a migration of these stocks westwards, both of which would lead to changes in the catch in different islands.