Damage to the Earth’s lands, largely caused by the expansion of agriculture, has put the planet on “crisis footing,” say the authors of a sweeping new report that urgently calls for the restoration of billions of acres of terrain to forestall the worst impacts of climate change.

The report, published Wednesday, is the second major report from the United Nations Convention to Combat Desertification (UNCCD), a lesser-known U.N. group that’s pressing the world’s countries, governments and industries to preserve and rehabilitate degraded lands and ecosystems. 

“Our health, our economy, our well-being depends on land. Our food, our water, the air we breathe are all coming from the land, at least partially,” said Ibrahim Thiaw, executive secretary of the UNCCD, in a call with reporters. “Humanity has already altered 70 percent of the land. This is a major, major figure.”

Underway for five years and written by land-use and ecosystem experts across 21 organizations, the report arrives at some sobering conclusions, including that up to 40 percent of the planet’s land is already degraded, affecting half of the people alive today. 

Landscapes—and with them, soil, water and biodiversity—underpin societies and economies, the authors say, and roughly half of global economic output is reliant on these natural resources, yet governments have failed to adequately account for and protect them. Restoring landscapes will be critical for societies and economies to survive, they report.

At current rates, an additional area nearly the size of South America will be degraded by 2050, unleashing roughly 17 percent of current annual greenhouse gas emissions every year as forests, savannahs, wetlands and mangroves are converted to agriculture or are lost to urban expansion.

The report comes weeks before the UNCCD is scheduled to gather in Côte d’Ivoire for its annual conference of the parties, or COP.  But the conference has received less attention than other U.N. conventions that will gather this year to address climate change and biodiversity loss.  

“The UNCCD is a convention that most people have never heard of, let’s be honest,” said Nigel Sizer, a land-use and policy expert with Dalberg Catalyst, a not-for-profit that works on sustainability projects. “They’re struggling to get attention for these very important issues—to get major donor governments to prioritize assistance and to get countries in the global south to prioritize these issues.”

“A good way to do that is to produce a report with really good data and be more vocal than U.N. agencies usually are,” Sizer added.

The UNCCD is making the case that the climate crisis, biodiversity loss and land degradation are integrally linked. 

“These conventions are being negotiated at the same time for a reason,” Thiaw said. “They’re three pieces of a puzzle.” That echoes language in the report: “We cannot stop the climate crisis today, biodiversity loss tomorrow, and land degradation the day after. We need to tackle all these issues together.”

Degradation of land occurs in a variety of ways, and includes deforestation, desertification and the loss of wetlands or grasslands, all of which can be caused by human activities. Restoration, similarly, takes a number of forms, including planting forests and shrubs or grazing livestock and growing crops between trees.

“Restoration means different things depending on the location and the ecology. There are all sorts of traditional and new systems that improve the carbon, lift up the water table and restore soil health,” said Sean DeWitt, director of the Global Restoration Initiative at the World Resources Institute. “These are the more regenerative systems that can improve productivity, store more carbon and provide more habitat for animals. These are virtuous cycles.”

The report puts much of the blame for degraded landscapes on humanity’s ever-expanding need for food and the modern farming systems that produce it. The global food system is responsible for 80 percent of the world’s deforestation, 70 percent of freshwater use and is the greatest driver of land-based biodiversity loss, the authors note. Modern agriculture “has altered the face of the planet more than any other human activity,” they write.

The industrial agricultural revolution of the last century, which delivered higher yields and more abundant crops, came at the expense of healthy soil and relied on higher levels of emissions-generating fertilizer, the authors say.

“I was struck by the pretty clear message that large-scale industrial agriculture and commercial-scale land conversion and clearing is a really big part of the problem,” Sizer said. 

The report emphasizes that land restoration is possible, despite current trends, and argues that 5 billion hectares—in total, an area five times the size of China—could be restored by 2050. Much of that could be achieved through changes in agricultural practices, including by avoiding heavy tillage, integrating trees with crops and livestock and rehabilitating grasslands and forests. Consumers, too, have a role to play, the authors argue, by shifting away from resource-intensive livestock-based diets that are responsible for higher carbon emissions.

Transforming the food system could make a “a significant contribution to the success of the global land, biodiversity, and climate agendas,” they write. 

Many of these fixes are low-tech, accessible and don’t necessarily require massive amounts of capital, the authors argue. They estimate it will cost $300 billion each year to “achieve significant” land restoration by 2030, which is far less than the subsidies provided to farmers in developed countries. 

“It’s possible to do this without additional taxpayer money,” Thiaw said.

Already, countries have pledged to restore 1 billion hectares—a land mass about the size of the United States. Much of that comes from the UNCCD efforts and from the Bonn Challenge, an initiative launched in 2011 by the International Union for the Conservation of Nature, which aims to restore 350 million hectares of land by 2030. So far 61 countries have signed on.

“These are just political commitments, so this is just the starting point,” DeWitt said. “To the extent that those have led to deeper government commitments, it varies. There are some front runners, and then there are others that are waiting to see and there hasn’t been a ton of traction.”

“It’s definitely climate-relevant,” DeWitt added. “The question is can we achieve 350 million? There has to be a sea change. We’re still degrading like crazy. Restoration is what you have to do to atone for your sins, but you need to stop sinning first.”