A tract of Amazon rain forest, which has been cleared by loggers and farmers for agriculture, is seen near the city of Santarem, Para State, on  April 20, 2013. (Nacho Doce/Reuters)

Calculating the economic value of nature — how much the world’s rain forests, grasslands and other natural areas are worth monetarily — is an approach many environmentalists are adopting in the fight to protect Earth’s dwindling wild spaces. The idea is that nature provides certain valuable benefits to humans, called “ecosystem services.” And damaging or destroying nature in a way that reduces these services actually costs us in the long term.

It’s easy to see how natural features like trees or rivers might benefit humans. But research suggests that the land  itself — the very soil that makes up the Earth — is a valuable resource. Healthy soil, for instance, can recycle nutrients, provide growing space for food and timber  and absorb carbon that would otherwise end up in the atmosphere and accelerate global climate change. Yet humans degrade, or reduce the quality of, the land all the time by clearing it, over-farming it or polluting it.

It turns out these practices could be a costly mistake. A new report published Tuesday by the Economics of Land Degradation Initiative claims that land degradation is costing the world $6.3 to $10.6 trillion in ecosystem service losses every year. In terms of land area, these losses work out to  $43,000 to $72,000 per square kilometer of degraded land. According to the report, about one third of the world’s arable land (land suitable for growing crops) has  been affected by degradation. These losses are also capable of displacing millions of people around the world.

But there’s good news, too: If we adopt more sustainable land management practices, the report argues, we could not only recover these losses  but actually end up generating more than $75 trillion dollars in annual global income. 

“We have estimated that anywhere between 10 and 17 percent of global gross domestic product is basically lost each year as a result of land degradation,” says Zafar Adeel, director of the Institute for Water, Environment and Health at United Nations University and a contributor to the report. “So the problem is really quite significant.”

The researchers used two separate models to arrive at the $6.3 and $10.6 trillion amounts, says Naomi Stewart, a project associate at United Nations University’s institute for Water, Environment and Health and the report’s editor. She says the difference is that the model that produces the higher total includes more indirect effects, such as malnutrition or conflicts over natural resources, which are caused by land degradation but don’t only happen at the site where the degradation is occurring.

One major indirect effect of land degradation is the forced migration of humans. If the land in one area isn’t providing the resources that people need to survive, such as adequate food supplies and clean water, then they will have to relocate. These migrations often begin as internal movements within countries, often from rural areas into cities, says Louise Baker, an external relations coordinator for the United Nations Convention to Combat Desertification. However, even these types of internal migrations can lead to civil unrest as “communities move from one area into another and come into conflict with the populations already there,” Baker says.

So finding more sustainable ways to cultivate and manage land is not just an economic boon — it provides an important social service as well. “We would rather look at it the other way: not how many people might move by 2020, but, say, how many lives can you improve and and how,” Adeel says.

Sustainable land management includes practices like greener farming or urban planning. Actually getting people to adopt these practices can be tricky, though. One method is for policymakers to offer incentives, such as government subsidies for individuals or companies that use sustainable practices. Another tactic is eco-labeling, in which products developed on sustainably managed land — timber, for example — are labeled and marketed as such.

“There is no single silver bullet that will solve the problem everywhere,” Adeel says. “You really do have to take into account the local social and economic conditions and work with the government institutions that are in place.”

And in turn, local governments need to be willing to work with the people, says Richard Thomas, director of the drylands program at the International Center for Agricultural Research in the Dry Areas and another contributor to the report.

“There needs to be a much more open dialogue between the actual people occupying the land, the governments and the private sector,” Thomas says. “And I think we will only get true successes when we get at least those three sectors sitting down and talking together.”

And keeping conversations focused on the benefits of sustainable land management may be one of the most important strategies of all. “We’ve tried to move the debate away from this negative rhetoric of land being degraded and focus it more on the positive, in terms of the rewards when sustainable land management practices are adopted,” Thomas says.