Farmers like Badsha Alal, 69, say they have witnessed changes in climate firsthand. Alal lives in Noakhali, a flood-prone area in south-central Bangladesh. Rains don't come when they used to, he says, and now the water comes in sudden, heavy bursts rather than falling evenly. Changing patterns means that age-old cultivation techniques are failing, making it harder for many farmers to work the land.