Torrential floods in Kenya have killed nearly 200 people and displaced hundreds of thousands more since March. The deluge comes on the tail of a years-long drought that left millions hungry.

This extreme weather whiplash is just one example of the grim toll climate change is taking in some countries. Around the world, more than 3 billion people have been affected by it over the past 20 years — but those impacts are very unevenly distributed, according to a new Conservation International study .

The global study analyzed the number and location of people injured, made homeless or killed after a hurricane, typhoon or other climate disaster.…