Nicki Bennett is an American aid worker who bounces around from one hot spot to the next, working for Oxfam. She has been deployed to Sudan, eastern Congo, Chad, Zimbabwe, Malawi, Zambia and Guatemala. She is currently in Bangladesh working on post-hurricane reconstruction.

This week I’m back in Dhaka, the world’s undisputed rickshaw capital. With more than 300,000 of these brightly colored bicycle contraptions plying the city’s streets for trade, I rarely walk for more than a block before a rickshaw driver (known as “rickshaw-wallah”) pulls up next to me and urges me to hop on board.

I’ve learned it’s almost impossible to refuse a ride. This is partly because the rickshaw-wallahs are very persistent, partly because I feel I should be supporting people struggling to make a living (one in five of the city’s inhabitants depends on the rickshaw business for their income) and partly because Dhaka is now starting to get unbearably hot and humid (and I’m starting to get horrendously lazy).

Coming back from a meeting near my office this afternoon, I start chatting (well, mainly hand-gesturing) with my rickshaw-wallah and ask him where he’s from. I’ve heard lots of stories about families in the cyclone-affected coastal areas sending sons or brothers to urban centers like Dhaka to make a little bit of cash driving rickshaws (many people have not been able to return to their regular jobs as the cyclone destroyed their fishing boats and nets or washed away their crops). I’m wondering if my rickshaw-wallah is one of them.

Instead, he names a district that I’ve never heard of. We manage to establish that it’s somewhere north of Dhaka, near a river. “Floods,” he tells me. “In my village. Village underwater.” Finally the penny drops – he’s not just an economic migrant, he’s also a “climate migrant.”