ADDIS ABABA, Ethiopia — Business is booming on the small patch of land where Eyasu Debela and four friends run a store by the side of the road selling tree seedlings for people to plant. The stock in their tree nursery on the outskirts of the Ethiopian capital, Addis Ababa, spans more than 15 varieties, from avocado and mango to olive and rosemary, and shoppers are flocking in as people in Africa’s second-most populous nation embrace one of the largest tree-planting campaigns the world has ever seen.

“People are encouraged to plant seedlings. So many of them come to us,” Debela, 29, told NBC News last month. Ethiopia’s rainy season between June and September is the busiest period, when radio, television and flyers urge people to plant trees across the country, he added. Launched by Prime Minister Abiy Ahmed in 2019, the Green Legacy Initiative has turned tree planting into a national obsession, mobilizing tens of millions of Ethiopians in a drive toward 50 billion trees by 2030.

The government says it has already planted more than 48 billion, including a single-day record of over 800 million seedlings in August. The campaign exists to confront a problem decades in the making: deforestation, eroding soil and a warming climate have left soil that no longer holds water, leading to crop failure and, in the worst cases, deadly landslides. Officials call it one of the most ambitious restoration efforts on Earth, and there are signs that degraded land is recovering as forest cover climbs for the first time in generations.

But experts caution that mass tree-planting schemes don’t always deliver what they promise, while the country is also wrestling with the impacts of conflict and climate change.

Forests once covered an estimated 35% to 40% of Ethiopia, but by the late 1980s, deforestation, overgrazing and expanding farmland had reduced that to less than 3%, driving the soil erosion that helped fuel the devastating famines of that era, according to a 2020 study published in the journal Environmental Systems Research.

The annual cost of soil degradation “is estimated to be about $4 billion,” according to Beyene Teklu, an agricultural economist at Ethiopia’s Hawassa University, who said that erosion can cut crop yields by as much as 30% in some areas, a hit that lands squarely on the nation’s 12 million smallholder farmers and the food supply they support.

It’s a pattern that the government says it’s now determined to reverse. As part of the Green Legacy Initiative, it distributes free seedlings to farmers in rural areas hit hardest by degradation, and to entrepreneurs in the city like Debela, whose nursery got its start on government-provided land.

The government “provided us with free nursery space, and we have also received training on the care and maintenance of seedlings at the government’s expense,” Debela said.

In the 10 years between 2013 and 2023, the annual deforestation rate fell from 92,000 hectares to 27,703 hectares, according to the government’s 2023 National Forest Cover report, which also noted that forest cover increased from 15.5% to 23.6% during the same period.

“Ethiopia is one of those countries in Africa that really is showing how it’s done,” said Peter Okaalet Alele, Africa regional director for the Forest Stewardship Council, a global nonprofit that sets standards and certifies sustainable management of the world’s forests that is working to certify roughly 4 million hectares of Ethiopia’s restored land. The sheer breadth of citizen involvement — farmers, students, civil servants, soldiers — is what sets the campaign apart, he said.

“You need massive action, massive investment. You need every hand you can get.”But getting trees in the ground is only half the battle.

A 2023 study of reforestation projects across Asia led by the U.K. Centre for Ecology & Hydrology found that roughly half of planted trees at 176 sites didn’t survive five years. The chances of survival depended in part on where and how the trees were planted: Trees planted in more sheltered, already forested areas tended to fare better, as did larger seedlings, the study found. Researchers also caution that forest-cover figures can be sensitive to how “forest” is defined and measured, making comparisons between datasets and over time more complicated. Aad Kessler, a researcher at the Netherlands’ Wageningen University who studies sustainable land management, said the intention to regreen was “highly laudable,” but that the campaign raises basic questions that are hard to answer from the outside.

“How many of these trees survive? Where do they plant those trees?” he said. Ideally, he added, “you involve the local population, creating ownership, and plant the trees on sites where they can water them if needed, which requires investing in awareness-raising.”

Abreham Berta Aneseyee, an environmental scientist at Ethiopia’s Wolkite University and an adviser to Ethiopia’s Ministry of Agriculture, pushed back on the idea that the campaign is planting blind, saying training ran alongside the campaign. He said government experts visit villages house to house, advising farmers on forestry, livestock and land management alongside the planting itself. But there are also places the campaign simply cannot reach.

Parts of northern Ethiopia, including the states of Amhara and Tigray, have been gripped by conflict in recent years, and fighting has continued to flare despite a peace deal formally ending the two-year Tigray war in November 2022. This week, conflict monitoring group ACLED reported that Eritrean troops had crossed into northern Ethiopia to support the Tigray People’s Liberation Front — a paramilitary group fighting for more autonomy in the region, parts of which are claimed by both countries. Aneseyee, who visited Tigray six months ago, said the toll on the landscape there is severe.

“It’s obvious if there is instability, the environment is more affected than any other sector,” he said. “War is devastating the environment significantly.”There are also doubts about whether planting trees can outpace the climate disasters they’re meant to help prevent.

In July 2024, a landslide struck Kencho Shacha Gozdi in Ethiopia’s southern Gofa Zone after heavy rain, killing 274 people and displacing hundreds — the deadliest such disaster in Ethiopia’s recent history. Tadesse Tadele, who lost his mother, father, two brothers and a sister that day, said seedling planting began in June this year, but that “no significant reforestation, land management or related activities had been carried out in the area” before that. “The threat of further landslides is still there, and we should be afraid,” the 25-year-old added. Seleshi Bekele Awulachew, Ethiopia’s former minister of water, irrigation and energy, said that in landslide-prone terrain, steep slopes and shifting rainfall patterns compound the risk regardless of how many trees go into the ground.

“The effect of climate change is intensifying the extreme events,” he said. “Wet extreme seasons become much wetter. Extreme dry seasons become more extreme.”

But determined to restore the land, farmers like Shambel Sharew keep planting. The 56-year-old father of three, who lives on the outskirts of Shewarobit town in Ethiopia’s northern and drought-stricken Amhara Region, said he planted grevillea, geranium, moringa, kesel and other seedlings in a public area this summer, and lemon, mango and avocado trees around his home.

“People here depend on this land,” he said. “If it is not restored, there will be nothing left to grow and no life.”