Ekaru Loruman lay beneath a flat-topped acacia tree, its latticework of branches casting a soft mesh of shade upon his body. He wore a silver earring and khaki shorts, and lay on his side with his arm twisted awkwardly beneath him. The left side of Ekaru’s forehead was gone, blown away by the exit of a bullet. His blood formed a greasy black slick on the desert floor. His sandals, shawl and gun had been stolen.

Ekaru had been a pastoralist from the Turkana tribe who live in northwest Kenya, on the arid savannas of the Rift Valley. He had been killed the day before when a neighboring and related tribe, the Pokot, launched a massive cattle raid. Ekaru’s corpse lay here on the ground exposed to the elements with goats and sheep browsing nearby because the Turkana do not bury people killed in raids. They believe doing so is bad luck; that it will only invite more attacks. So they leave their dead to decompose where they fall. But these supernatural precautions will not hold the enemy at bay, for there are profound social and climatological forces driving them to attack.

The group of Turkana I was visiting had been pushed south by severe drought and were now grazing their herds at the very edge of their traditional range. In the pastoralist corridor of East Africa a basic pattern is clear: during times of drought, water and grazing become scarce, the herds fall ill, many cattle die. To replenish stocks, young men raid their neighbors. The onset of anthropocentric climate change means Kenya is seeing rising temperatures and more frequent drought. Yet, overall it is actually receiving greater amounts of precipitation. The problem is, the rain now arrives erratically, in sudden violent bursts, all at once, rather than gradually over a season. This means eroding floods, followed by drought. The clockwork rains, upon which Kenyan agriculture and society depends, are increasingly out of sync.