The two elders, wearing weather-beaten cowboy hats with the strings cinched under their chins, stood at the edge of an empty farm, covering their mouths in disbelief.

Their homes — neat wooden cabins — had been smashed open. All their cattle had been stolen. So had their chickens. House after house stood vacant, without another soul around. It was as if some huge force had barreled into the village and swept away all the life.

Sioyia Lesinko Lekisio, one of the elders, had no doubts who did this. Swarms of herders from another county had invaded, attacking any farm or cattle ranch in their path, big or small, stealing livestock, ransacking homes and shooting people with high-powered assault rifles.

“There’s nothing we can do about it,” he said. “They want our land.”

Kenya has a land problem. Africa itself has a land problem. The continent seems so vast and the land so open. The awesome sense of space is an inextricable part of the beauty here — the unadulterated vistas, the endless land. But in a way, that is an illusion. 

Population swells, climate change, soil degradation, erosion, poaching, global food prices and even the benefits of affluence are exerting incredible pressure on African land. They are fueling conflicts across the continent, from Nigeria in the west to Kenya in the east — including here in Laikipia, a wildlife haven and one of Kenya’s most beautiful areas.

Large groups of people are on the move, desperate for usable land. Data from NASA satellites reveals an overwhelming degradation of agricultural land throughout Africa, with one recent study showing that more than 40 million Africans are trying to survive off land whose agricultural potential is declining.

At the same time, high birthrates and lengthening life spans mean that by the end of this century, there could be as many as four billion people on the continent, about 10 times the population 40 years ago.

It is a two-headed problem, scientists and activists say, and it could be one of the gravest challenges Africa faces: The quality of farmland in many areas is getting worse, and the number of people squeezed onto that land is rising fast.

“It’s a looming crisis,” said Odenda Lumumba, head of the Kenya Land Alliance, a group that works on land reform. “We are basically reaching the end of the road.”

More than in any other region of the world, people in Africa live off the land. There are relatively few industrial or service jobs here. Seventy percent of Africa’s population makes a living through agriculture, higher than on any other continent, the World Bank says.

But as the population rises, with more siblings competing for their share of the family farm, the slices are getting thinner. In many parts of Africa, average farm size is just an acre or two, and after repeated divisions of the same property, some people are left trying to subsist on a sliver of a farm that is not much bigger than a tennis court.

A changing climate makes things even harder. Scientists say large stretches of Africa are drying up, and they predict more desertification, more drought and more hunger. In a bad year, maybe one country in Africa will be hit by famine. This year, famine is stalking three, pushing more than 10 million people in Somalia, Nigeria and South Sudan to the brink of starvation.

But much of Africa’s farmland is in danger for another, perhaps simpler, reason: overuse. Fast-growing populations mean that many African families can’t afford to let land sit fallow and replenish. They have to take every inch of their land and farm or graze it constantly. This steadily lowers the levels of organic matter in the soil, making it difficult to grow crops.

In many areas, the soil is so dried out and exhausted that there is little solace even when the prayed-for rains finally come. The ground is as hard as concrete and the rain just splashes off, like a hose spraying a driveway.

“There are going to be some serious food-security issues,” said Zachary Donnenfeld, a researcher at the Institute for Security Studies in South Africa. “More and more countries will be reliant on food imports. You’ll increasingly see the international community come into more rescue-type situations.”

The fact that several of Africa’s biggest economies have grown impressively in the past 10 years may seem like an answer, but analysts say the newfound affluence may actually compound these pressures.

As people gain wealth, they consume more — more energy, more water and usually more meat, all of which intensify the pressures on the environment. In Kenya, a piece of meat is one of the first things people treat themselves to when they get a little extra cash, and as the nation’s economy grows, so does the taste for beef. Cows have always been a traditional form of wealth; now they’re big business. In the past 15 years, the number of cows in Kenya has shot up by more than 60 percent to around 20 million, driving a scramble for grazing lands.

Some parts of Kenya are now so overgrazed by cows and goats that all the grass roots have been eaten, leaving large stretches of bare earth, as measured by NASA satellite imagery that tracks net levels of carbon dioxide absorption. Herders from bare-earth zones in Kenya are often the ones invading ranches.

Private investors are tramping in as well. Since the 1990-2005 period, global food prices have increased by 50 to 75 percent. Many foreign companies and local businesspeople have speculated that despite soil degradation, African farmland is destined to become more valuable. Small landholders across the continent are increasingly getting priced out or even evicted to make way for big commercial farms. This has led to conflict even in usually peaceful places, like Malawi, where a land-defense movement recently started to fight back against foreign-owned tea plantations.

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