Torrential rains that triggered floods and landslides have killed hundreds of people and displaced millions across parts of Africa, Europe, Asia and the US in recent months.

The unprecedented deluges overwhelmed even communities accustomed to extreme weather and showed the limitations of the early-warning systems and emergency protocols established in many countries to avoid major loss of life.

Climate scientists have warned that an accelerated water cycle is locked into the world’s climate system due to past and projected greenhouse gas emissions, and is now irreversible.

The communities that tend to pay the highest price are often in poorer countries, where environments can be more fragile and governance more patchy, and there are fewer resources to bounce back after a disaster.