An estimated 17.5 million people across South Asia are suffering as a result of the devastation of this year's monsoon floods. Nearly 700 have died.

A third of Bangladesh went underwater, including Hossain's district of Kurigram, after most of its 16 rivers overflowed following torrential rains and violent onrush of waters from upstream India, which was also tormented by the floods as rivers cut their ways from as far as the Himalayan nation of Nepal. Bangladesh, which is crisscrossed by 230 rivers, is the last channel through which waters are drained into the Bay of Bengal.

Experts have long been warning that a densely populated delta country like Bangladesh is one of the worst victims of climate change, and severe and frequent floods indicate that something has gone wrong.

"The current major floods affecting millions of people in Bangladesh along with super cyclone Amphan that hit the country a few months ago are both linked to human-induced climate (change) now becoming a reality," said Saleemul Huq, a Bangladeshi expert on climate change and director of the International Center for Climate Change and Development.

The impact of global warming in South Asia is evident by a steady sea level rise, changes in ambient temperature and rainfall patterns and an increase in cyclonic activity, experts say. More landslides and flooding are projected across the region, which is home to almost one-fourth of the world’s population. Thousands have already been displaced from low-lying islands in the Sundarbans, the world’s largest mangrove forest straddling Bangladesh and India.