The Sahel remains a sparsely populated region, and desiccated savannah dominates the landscape – stretching for miles into the distance. But look a bit closer, and you will see that the Sahel is really one big, busy highway - traversed not by humans, but by their massive herds of livestock. For untold generations, people here have consumed their milk and meat or sold it in nearby markets. Now however, as climate change has begun to hit the Sahel, herds are thinning out and their owners are suffering.