By Kieran Cooke

As another monsoon season begins, huge numbers of homeless Bangladeshis are once again bracing themselves against the onslaught of floods and the sight of large chunks of land being devoured by rising water levels.

Bangladesh, on the Bay of Bengal, is low-lying and crisscrossed by a web of rivers: two thirds of the country's land area is less than five meters (approximately 16 feet) above sea level. With 166 million people, it's one of the poorest and most densely populated countries on Earth—and one of the most threatened by climate change.