India, Feb. 21 -- Under a scorching sun, Moses Oleseki scans the cracked earth where a waterhole once brimmed with life. His herd of cows, goats and sheep lazily roam behind him, their protruding ribs visible beneath thinning hides.

"We used to have a lot of grass in this area," the 47-year-old Maasai pastoralist said. "Now, we have to walk miles to find water and pastures. It is very disturbing."

Pastoralists across Africa are grappling with recurring drought spells that have denuded rangeland. The worsening impacts of climate change, overgrazing and land conversion for agriculture and development are driving the continent's grasslands to the edge, threatening food security and livelihoods.

From the Sahel to the Horn of Africa, herde...