Claudia Stickler, a graduate fellow at the Woods Hole Research Center in Falmouth, Massachusetts, agreed the falling deforestation rates are mostly due to economic factors.
"But the scary thing is that this year and next year [the market] could certainly go up again, and there could be new clearing," she said.
For example, increasing demand for ethanol is causing U.S. farmers to abandon soy in favor of corn, which increases demand for Brazilian soy.
And in Brazil, demand for ethanol from sugarcane is also rising.
"That means that more land is going into sugarcane, which means that soy is being displaced in Brazil too," Stickler said.
"[Soy farming] needs to go somewhere, and mostly it is expanding north into the Amazon."
Soy is also a major source for biodiesel. As demand for the plant-based fuel increases, that demand could put even more pressure on the forests, she added. (See rain forest photos and video.)
WWF-Brazil's Hamú said environmental and economic policies in Brazil are misaligned.
For example, a government program to accelerate growth this year relies heavily on infrastructure projects like roads and dams, which aid deforestation, she said.
"What we are advocating is that nature should be seen as an asset and not as a barrier," she said.
The Brazilian government needs to invest in intensified agriculture—for instance, making the most of already cultivated land—to continue to curb deforestation and simultaneously grow the economy, Stickler said.
"If the decline in deforestation could be maintained, that would be fantastic," she said.
"Right now, carbon emissions from land-use change—which includes forest conversion—contributes about a quarter of annual global carbon emissions."
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