A grandmother named Mariao Tede is among them. Early one recent morning, on the banks of a dry stream, with the air tasting of soot and sand, Ms. Tede stood over a pile of dark embers, making charcoal. A reed of a woman who doesn’t keep track of her age, she said she once had 200 goats, enough to sell their offspring at the market and buy cornmeal for her family. Raising livestock is traditionally the main source of income in the region, because not much food will grow here.

Many of her goats died in the 2011 drought, then many more in the 2017 drought. How many were left? She held up five fingers. Not enough to sell. Not enough to eat. And now, in the dry season, not even enough to get milk. “Only when it rains I get a cup or two, for the kids,” she said.

The most recent drought has prompted some herders to plunder the livestock of rival communities or sneak into nature reserves to graze their hungry droves. Water has become so scarce in this vast county — known as Turkana, in northwestern Kenya — that fetching it, which is women’s work, means walking an average of almost seven miles every day.

Ms. Tede now gathers wood to make charcoal, a process that is stripping the land of its few trees, so that when the rains come, if the rains come, the water will not seep into the earth. On the roadside stood what were once sacks of food aid, now stuffed with charcoal, waiting for customers.