The report, brought out by Greenpeace, an environmental organization, takes into account the growing greenhouse gas emissions.

According to a report by BBC News, the study said that if global temperatures rise by about 4 - 5 degree Celsius in the course of the century - as they are projected to - the South Asian region could face a wave of migrants displaced by the impact of climate change.

Around 130 million people now live in India, Pakistan and Bangladesh in what are called low elevation coastal zones, which comprise coastal regions that are less than 10m above average sea level.

"Most of these people will be forced to leave their homes because of the sea-level rise and drought associated with shrinking water supplies and monsoon variability," said Dr Sudhir Chella Rajan, a climate expert and author of the study.

"The bulk of them will come from Bangladesh as most of the parts of that country will be inundated," he told the BBC.

According to Mohon Kumar Mondol, an activist from Bangladesh, that country is already experiencing the migration.

"Though Bangladesh is hardly responsible for the global warming and climate change, the Bangladeshi people are paying the price for it," he said.