As government leaders and forestry experts gathered in South Korea this week to discuss the state of the world’s forests, new research suggests that ambitious international efforts to curb deforestation are making insufficient progress and the planet’s trees continue to disappear.

On Wednesday, an international consortium of researchers released an assessment of the sweeping United Nations-sponsored program, known as REDD+, that was launched 15 years ago to compensate developing countries—home to most of the planet’s climate-critical tropical forests—for conserving and protecting their trees.

But the report, from the International Union of Forest Research Organizations, acknowledges that REDD+ has been riddled with problems, and its authors say that efforts to stop deforestation are being overwhelmed, in large part by giant agricultural corporations that are the driving force behind much of the forest loss.

“There’s massive commitment,” said Stephanie Mansourian, one of the report’s authors. “But at the end of the day, on implementation, we’re way behind.”

REDD, which stands for Reducing Emissions from Deforestation and Forest Degradation, was initially launched in 2007 at a U.N. conference on climate change. Over the following three years the “plus” was added to its name as it transitioned into its current form—a framework in which high-income countries pay for voluntary efforts by lower-income countries to restore and conserve forests. But the details on how these exchanges would occur were thin.

“It was an idealistic idea with very little meat to it,” Mansourian noted.

Since then, U.N.-led programs and international funds, including the Green Climate Fund, have pledged roughly $2.4 billion toward forest conservation efforts through REDD+. About $500 million of that total has been fully allocated to eight countries, including Brazil and Indonesia, as “results-based payments.”

But in another assessment, also published this week to coincide with the World Forestry Congress underway in South Korea, the U.N.’s Food and Agriculture Organization (FAO) says that the financial commitments need to be scaled up significantly—to about $200 billion a year “by 2030 to meet climate, biodiversity and land degradation neutrality targets.”  

“The tragedy of forest finance is that it has not been tried at significant scale. There’s just not enough money going into conservation that can compete in the marketplace with what’s being spent by big meat and big chocolate companies,” said Glenn Hurowitz, the head of Mighty Earth, a forest advocacy organization. “The goal is to make these forests more valuable standing than dead. There’s not enough money to achieve that goal.”

The FAO’s new report says that more than 1 billion acres of forest, mostly in the tropics, were lost between 1990 and 2020. And while rates of deforestation are slowing, the world still lost 25 million acres of forest a year between 2015 and 2020.  

When trees are left standing, they store carbon in their roots and the surrounding soils, absorbing as much as 29 percent of all man-made carbon emissions. Currently, about 10 percent of annual global carbon emissions occur from forests being cut or damaged, the report says. (Degraded forests, which are more difficult to measure than deforestation, contribute about one-third of these emissions.)

Since the inception of REDD+, global policy makers and researchers have increasingly acknowledged that restoring forests and keeping them intact is critical for reaching global emissions reductions targets. Over the last decade, global negotiations have embedded forest conservation goals into ambitious international efforts, including the Paris climate agreement, the U.N. Convention on Global Biodiversity, the U.N. Convention to Combat Desertification and, most recently, the Glasgow Leaders declaration on forests and land use, in which leaders of over 100 countries pledged to “halt and reverse forest loss and land degradation by 2030.” 

At the same time interest from the private sector has ramped up as corporations attempt to reduce their carbon footprints, in part by buying forest-based carbon credits.

“We’re entering a whole new ballgame for private sector demand,” said Frances Seymour, a distinguished senior fellow with the World Resources Institute and a board member of Architecture for REDD+ Transactions (ART), an organization that creates standards for forest carbon credits.

A significant component of REDD+ is the encouragement of voluntary markets in which these carbon-emitting private industries pay for a carbon “offset” or credit that’s generated when a forestry project leaves trees standing. 

But monitoring those credits and ensuring they generate the claimed carbon offsets has been problematic. The authors of the report say, while there’s been significant progress in assessing forest destruction, persistent “knowledge gaps hamper measurement, reporting and verification of carbon outcomes of REDD+. These include, among others, discrepancies between different datasets; lack of country-specific data; inadequate reporting on estimate uncertainty; insufficient resolution of satellite imagery to monitor forest degradation; lack of inclusion of other carbon pools such as deadwood or soil carbon; and the uncertainty surrounding the impact that climate change will have on forests and their carbon sink function.”

The REDD+ program, the authors acknowledge, has turned out to be much more complicated to administer than they had anticipated, and is confronting a variety of challenges, from verifying what constitutes a legitimate credit to ensuring that forest-based communities are getting a fair deal.  Amid all the complications, the program faces “ongoing tensions” between environmental and development goals, for example “the need to rein in the global finance and commodities sectors as drivers of deforestation, while also courting them as critical sources of REDD+ funding.”

The report also makes a somewhat startling conclusion. Given all the recent research, including from the Intergovernmental Panel on Climate Change (IPCC), that forests are critical to staving off the worst effects of climate change, they can’t do everything—and the world may be asking too much of them.

“There can be no substitute of land-based emissions reduction for the decarbonization in other sectors,” Seymour said. “The report is correct: Forests aren’t everything. We need reductions from fossil fuels.”

“This experience has been a bit sobering about how hard this is,” she added. “Reducing emissions from the land sector may indeed be cheaper, but it’s certainly not easier.”

Still, Seymour remains optimistic that REDD+ can still work. “REDD+ remains a great idea that’s hardly been tried,” she said.