The tropical forests in western Uganda, home to a dwindling population of endangered chimpanzees, are disappearing at some of the fastest rates on Earth as local people chop down trees for charcoal and to clear space for subsistence farming.
Now, a team of researchers has shown that there is a surprisingly cheap and easy way to slow the pace of deforestation in Uganda: Just pay landowners small sums not to cut down their trees. Their study, published in the journal Science on Thursday, demonstrated this by conducting something all too rare in environmental policy — a controlled experiment.
The idea of paying people in poorer countries to protect their forests has long attracted interest from those concerned about climate change. The United Nations set up a program, known as REDD Plus (for reducing emissions from deforestation and forest degradation), to channel $10 billion from wealthy donors like Norway and Japan to poorer nations to slow deforestation trends responsible for about 10 percent of man-made greenhouse gas emissions each year.
The idea sounds simple: When trees are cut down and decompose or are burned, they release the carbon dioxide they soaked up from the atmosphere. Keeping them intact can help slow the pace of global warming.
Yet many experts have long been skeptical that such “payment for ecosystem services” programs actually work. How does anyone know the money is not just flowing to people who would have preserved their forests anyway? What if people take money to protect their own land but then go cut down trees elsewhere?
“Unless you set up a randomized trial, where you’re carefully comparing people who take part in the program with people who aren’t, it’s hard to know if you’re having any effect,” said Seema Jayachandran, an economist at Northwestern University and the lead author of the study.