TOPSHOT - Traditional Samburu tribes-people shelter in the shade of an acacia at Merille livestock market, some 411km north of Nairobi in Kenya's Marsabit county, on April 30, 2019. - Nomadic livestock herders in East Africa's drylands have endured climate variability for millennia, driving their relentless search for water and pasture in some of the world's most inhospitable terrain. (Photo by TONY KARUMBA / AFP)