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

Tropical forests face a lot of threats, particularly from the logging and agriculture industries. Their continued disappearance from the face of the Earth is therefore no great news — but new research suggests that they may be disappearing even faster than we thought. And that could have big implications for the global effort against climate change.

A new report from the Center for Global Development, released Monday, warns of what will happen if world leaders don’t take stronger steps to cut down on deforestation — that is, if we follow a “business-as-usual” trajectory. By 2050, they estimate, an area of forest equal to the size of India will be lost. The researchers came to their conclusions by using published satellite data on global forest cover from 2001 to 2012 to assess current rates of deforestation around the world.

There are some limitations to the data set the researchers used. For one thing, the satellite data are unable to distinguish between different types of tree cover, meaning tree plantations get lumped in with natural forests. This means there’s the potential for the data set to over- or underestimate the amount of natural forest being lost each year, and the researchers say future studies should attempt to investigate this issue. However, the data otherwise turned up some alarming findings.

“Unlike many previous studies, we actually project that if we do nothing, deforestation in the tropics will accelerate,” says Jonah Busch, one of the authors and a research fellow at the Center for Global Development. (Busch published the study along with colleague Jens Engelmann.) Judging from the patterns they observed using the satellite data, the researchers believe that deforestation under a business-as-usual scenario will climb steadily for the next several decades and then slightly accelerate in the 2040s.

Losing so much of the world’s forests is bad enough for the plants and animals that depend on them to survive. But even more alarming are the implications for global climate change. Currently, world leaders are working to keep global temperatures from rising more than 2 degrees Celsius. But in order to meet that goal, scientists say, there’s a limited amount of carbon humans can continue to pour into the atmosphere in the coming decades.

Cutting down on the burning of fossil fuels and transitioning to renewable energy sources is a major way nations around the world are working to meet the 2-degree goal. But forests contain huge stores of carbon as well, which get dumped into the atmosphere if the trees are destroyed. The new paper points out that the India-sized chunk of tropical forest we’ll lose under a business-as-usual trajectory will release about 169 gigatons of carbon dioxide into the atmosphere — that’s a sixth of our remaining carbon budget. These emissions are tantamount to what would happen if we ran approximately 44,000 new coal plants per year, Busch says.

That’s a substantial portion of the budget to burn through by mid-century. But the researchers say there are several effective ways to start cutting down on deforestation. Setting up international carbon payments — in which wealthy countries pay other nations to keep their tropical forests standing — is one option. Introducing domestic carbon prices, which are essentially taxes that must be paid for the right to emit a certain amount of carbon, is another possibility. Or countries could simply enact more restrictive policies on deforestation. In fact, some nations have already enacted such policies or have pledged to enact them in the future, offering hope that the dire scenario described in the paper could still be avoided.

The researchers checked out how much carbon could be saved by introducing these policies all over the world. They found that universally applying a price of $20 per ton of carbon dioxide between 2016 and 2050 would prevent 41 gigatons of carbon dioxide from being emitted due to forest destruction. And a price of $50 per ton would save 77 gigatons of carbon dioxide.

Simple anti-deforestation policies can be effective too. The researchers used the policies enacted in Brazil as a model since, as Busch says, “Brazil has been the world’s biggest climate success story in the last decade.” Since 2004, he says, the country has slashed deforestation of the Amazon by nearly 80 percent. The researchers found that if all countries enacted anti-deforestation policies as effective as those in Brazil, 60 gigatons of carbon emissions could be avoided.

One other important point to note, according to Busch, is that reducing emissions from deforestation is relatively cheap compared to reducing emissions from other sectors, such as energy or transportation. Emissions from tropical deforestation are about equivalent to emissions put out by the European Union, Busch says — but cutting down on deforestation through any of the means described above only costs about a fifth of what it would take to cut an equivalent amount of emissions in the European Union.

It’s an opportunity for the world to address a significant carbon source in a comparatively cheap way, the authors argue. And, according to Busch, it’s also an opportunity for wealthy countries such as the United States to step up and start putting more money into international carbon payments or other global deforestation efforts.

“This is a real opportunity for the U.S. to show leadership, and not just leadership at home, but internationally,” Busch says. “[U.S.] funding in this area is quite small at the moment, so a little more could go a long way.”

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