OSLO, Norway — Tropical forests are essential for keeping carbon in the ground and maintaining the climate. When Amazonian forests are converted into savannah, there’s less rainfall and more drought.

The current rate that we’re clearing the Amazon and other tropical forests in Southeast Asia and Central and West Africa is putting us on a course for rapid, irreversible, and catastrophic climate change, with an intensifying cycle of extreme droughts, more heat, and more forest fires. All told, deforestation accounts for an estimated 15 percent of total greenhouse gas emissions.

Given forests’ importance, new data from the University of Maryland released on Global Forest Watch, a forest monitoring site, is alarming: 2017 was the second-worst year on record for tropical forest loss. Some 39 million acres of trees, an area the size of Bangladesh, were destroyed. That’s about 40 football fields of trees lost every single minute.

2017 turned out to be only slightly better than 2016, which was the worst deforestation year to date due mainly to an El Niño-related drought and the major spike in fires it caused in Brazil.

“This is a crisis of existential proportions,” Ola Elvestuen, Norway’s minister of climate and environment, said Wednesday at the Oslo Tropical Forest Forum where the data was released. “We either deal with it or we leave future generations in ecological collapse.”

What caused deforestation in 2017?

As the chart shows, deforestation in the tropics has been accelerating. Which means we are not keeping up with — much less reversing — the growing pressures on forests from people clearing and burning them for agriculture, livestock, and timber.

Governments, corporations, and local communities are taking the issue more seriously. But many factors contributed to the extraordinary destruction of forests last year.

Deforestation increased significantly in a few countries in 2017, most notably Colombia and the Democratic Republic of Congo. In Colombia, the peace process and the demobilization of the Revolutionary Armed Forces of Colombia (FARC) left a power vacuum in vast, remote forest regions. With the rebel group no longer controlling the forest areas (and the lack of any other government entity to regulate them), opportunists moved in to log and clear land to plant coca and other crops.

Overall in 2017, Colombia lost 1 million acres — 46 percent more than the previous year. In the DRC, some 3.4 million acres of forest were lost to agriculture, artisanal logging, and charcoal production.

Brazil had success slowing deforestation between 2004 and 2012 through better monitoring and crackdowns on illegal activity, incentives for farmers to not clear forests, and programs to cut off illegal soy and cattle producers from markets.

But in a dramatic turnaround, tree cover loss doubled there from 2015 to 2017. As the World Resource Institute’s Frances Seymour writes, this is “in part due to unprecedented forest fires in the Amazon ... [and] to a relaxation of law enforcement efforts in the midst of the country’s ongoing political turmoil and fiscal crisis.”

According to Carlos Nobre, a Brazilian scientist and expert on climate change, we’ve already deforested about 18 percent of the Amazon. Reaching 20 to 25 percent deforestation would cause the “system to flip to non-forest ecosystems in eastern, southern and central Amazonia,” he wrote with Thomas Lovejoy in a recent paper in Science Advances.

“We are very close to 20 percent,” he said Wednesday at the Oslo Tropical Forest Forum. “We need to stop completely Amazonian deforestation. We do not want the Amazon to become a global cattle ranch.”

In most tropical regions, demand for soy, beef, palm oil, and other commodities — as well as fires — is driving the bulk of deforestation. In Brazil, which lost 11 million acres of forest cover in 2017, the main use for cleared land is cattle pasture.

In the Caribbean, the total forest lost during the 2017 Atlantic hurricane season was small compared to Brazil and DRC. But the Category 4 hurricanes that pummeled the region still did a number on forests there. The island of Dominica lost 32 percent of its tree cover in 2017, while Puerto Rico lost 10 percent.

Why stopping deforestation is so difficult

So what to do about it?

In the past 10 years, we’ve seen more and more ambitious international commitments on forests and climate change, including the Paris climate agreement, REDD+, and the Sustainable Development Goals. Better satellite images, remote sensing, and other technologies are helping law enforcement respond to illegal deforestation far quicker. More and more companies are committing to only buying from producers who can certify they are improving the environment.

“It comes down to regulation, enforcement, and incentives,” said Norway Environment Minister Elvestuen.

Some countries actually saw a drop in tree cover loss in 2017. Indonesia achieved a decrease because of a moratorium on converting peatland, better education of farmers, and enforcement around burning forests, according to the new report.

But it’s not enough. According to Seymour, who spoke Wednesday in Oslo, “We know what it takes. And we’re not doing enough of it, and we don’t have enough help to do it.”

The list of things we need to do is very long and very challenging, especially given the growing appetite for meat and other commodities like palm oil, timber, and cocoa. We need to shift global diets and lower meat consumption. We need to persuade farmers not to burn forests.

In the case of Brazil, cattle pasture is the main use of cleared land. And farmers “have grown weary of being vilified as criminals, of unmet promises of positive incentives for shifting to sustainable production systems...” write Daniel Nepstad and João Shimada of the Earth Innovation Institute for Mongabay. “To gain the support of conservation-minded, responsible farmers for the deforestation agenda, a new narrative and set of actions is needed that recognizes, applauds and rewards them for their efforts as it effectively includes them in dialogues.”

Increasingly, forest advocates are talking about connecting people who live in or near remaining tropical forests with opportunities to restore them. The Nature Conservancy, for instance, has been heavily involved in a new initiative with 7 other institutions called Nature4Climate, that will try to engage farmers and others around reforestation and conservation agriculture.

“We can’t have self-righteous NGOs just telling people ‘you can’t cut down your forests,’ anymore,” Justin Adams, TNC’s managing director of global lands, told Vox. “We want to help countries manage land and trade carbon as an asset. There has to be an economic opportunity for tropical forest countries in restoring ecosystems.”

On the bright side, there seems to be more dialogue across the board, around the world, than ever.