When the creek beside Taudibura Garo's school in Papua New Guinea floods, the water doesn't stop at the gate. It rises through the pit toilets – making the school unsafe – sending the 16-year-old and her classmates home without being able to finish.

Nepal’s call for financial compensation following recent deadly floods underlines the need to help countries that contribute the least to climate change – but are increasingly grappling with its most lethal consequences, the top UN official in the country said on Wednesday.