Leaders of more than 100 countries, including Brazil, China and the United States, vowed on Monday at climate talks in Glasgow to end deforestation by 2030, seeking to preserve forests crucial to absorbing carbon dioxide and slowing the rise in global warming.
The pledge will demand “transformative further action,” the countries’ declaration said, and it was accompanied by several measures intended to help put it into effect. But some advocacy groups criticized them as lacking teeth, saying they would allow deforestation to continue.
Prime Minister Boris Johnson of Britain was scheduled to announce the deforestation agreement at an event on Tuesday morning attended by President Biden and the president of Indonesia, Joko Widodo.
“These great teeming ecosystems — these cathedrals of nature — are the lungs of our planet,” Mr. Johnson is expected to say.
The governments committed $12 billion and private companies pledged $7 billion to protect and restore forests in a variety of ways, including $1.7 billion for Indigenous peoples. More than 30 financial institutions also vowed to stop investing in companies responsible for deforestation. A new set of guidelines offers a path toward eliminating deforestation from supply chains.
Many policy experts have called these measures an important step forward, while emphasizing that far more is needed.
“The financial announcements we’ve heard in Glasgow are welcome but remain small compared to the enormous private and public flows, often in the sense of subsidies, that drive deforestation,” said Frances Seymour of the World Resources Institute, a research group.
The pledge comes amid growing awareness of the role of nature in tackling the climate crisis, something Britain has sought to highlight at the climate summit, known as COP26. Intact forests and peatlands, for example, are natural storehouses of carbon, keeping it sealed away from the atmosphere. But when these areas are logged, burned or drained, the ecosystems switch to releasing greenhouse gases.
If tropical deforestation were a country, it would be the third-biggest emitter of greenhouse gases in the world, according to the World Resources Institute, after China and the United States. Much of the world’s deforestation is driven by commodity agriculture as people fell trees to make room for cattle, soy, cocoa and palm oil.
The value of healthy forests goes far beyond carbon. They filter water, cool the air and even make rain, supporting agriculture elsewhere. They are fundamental to sustaining biodiversity, which is suffering its own crisis as extinction rates climb.
Previous efforts to protect forests have struggled. One program recognized in the Paris climate accord seeks to pay forested nations for reducing tree loss, but progress has been slow.
Previous promises to end deforestation also have failed. A United Nations plan announced in 2017 made similar commitments. An agreement in 2014 to end deforestation by 2030, the New York Declaration on Forests, set goals without a means to achieve them, and deforestation continued.
The same will happen this time, some environmentalists predicted.
“It allows another decade of forest destruction and isn’t binding,” said Carolina Pasquali, executive director of Greenpeace Brazil. “Meanwhile, the Amazon is already on the brink and can’t survive years more deforestation.”
Supporters of the new pledge point out that it expands the number of countries and comes with specific steps to save forests.
“What we’re doing here is trying to change the economics on the ground to make forests worth more alive than dead,” said Eron Bloomgarden, whose group, Emergent, helps match public and private investors with forested countries and provinces looking to receive payments for reducing deforestation.
The participating governments promised “support for smallholders, Indigenous Peoples and local communities, who depend on forests for their livelihoods and have a key role in their stewardship.”
Tuntiak Katan, the general coordinator of the Global Alliance of Territorial Communities and a member of the Shuar people in Amazonian Ecuador, praised the support for Indigenous and local communities but questioned throwing money at a system he sees as broken.
“If this financing doesn’t work directly, and shoulder to shoulder, with Indigenous peoples, it’s not going to have the necessary impact,” he said.
This year, scientists found that parts of the Amazon have begun emitting more carbon than they store.
China is one of the biggest signatories to the deforest declaration, but the country’s top leader, Xi Jinping, did not attend the climate negotiations in Glasgow. China suffered heavy forest losses as its population and industry grew over the past decades, but more recently, it has pledged to regrow forests and to expand sustainable tree farming.
By China’s estimate, forests now cover about 23 percent of its landmass, up from 17 percent in 1990, according to the World Bank. Though some research has questioned the scale and the quality of that expanded tree cover, the government has made expanded reforestation a pillar of its climate policies, and many areas of the country are notably greener than they were a couple of decades ago.
Still, China’s participation in the new pledge may also test its dependence on timber imported from Russia, Southeast Asia and African countries, including large amounts of illegally felled trees.
In a written message to the Glasgow meeting, Mr. Xi “stressed the responsibility of developed countries in tackling climate change, saying that they should not only do more themselves, but should also provide support to help developing countries do better,” Xinhua news agency reported.