India, whose economy has grown by 8-9 percent annually in recent years, is one of the world's top polluters and contributes around 4 percent of global greenhouse gas emissions as its consumption of fossil fuels grows.

"We cannot wait for the inevitable to happen and hope to adapt to it," Vinuta Gopal, the group's climate and energy campaigner in India said, releasing the report on the ecologically sensitive region, one of the poorest in the world.

"We need policies that reduce the risk of destructive climate change, and moves towards economic development through decarbonisation," Gopal said.

The UN Development Programme in its latest report has also warned climate change will hit the world's poorest countries, increasing risks of disease, destruction of traditional livelihoods and triggering massive displacement.

Together, India, Bangladesh and Pakistan have nearly 130 million people living along coastal areas less than 10 metres (33 feet) above sea level, the Greenpeace report said.

"We are already seeing the effects," said Sudhir Chella Rajan, the author of the report and a professor at the Indian Institute of Technology.

He said the effect of rising temperatures was already apparent in the recurrent floods in coastal Bangladesh.

The number of people displaced by global warming could dwarf the nearly 10 million refugees and almost 25 million internally displaced people already fleeing wars and oppression.

Christian Aid has predicted there will be one billion people displaced by climate change globally by 2050.

India, Bangladesh and Pakistan have a total population of about 1.4 billion people.