Before 2009, nearly 4 in 10 cattle ranchers and slaughterhouse in Brazil reported recent deforestation but by 2013, this number dropped to 4 in 100, a 10-fold decrease.

What changed? Policies that were not simply advocated by first world elites that told people in Brazil they couldn't have an economy. Brazil is home to the world’s largest commercial herd of cattle, and its cattle ranchers were once linked to the destruction of huge swaths of rainforest. “Zero-deforestation agreements” put into place in 2009 use market-based strategies to reduce the impact of the beef industry on the environment, a much different methodology than in the past where some would follow guidelines and be penalized economically.

The United States has had similar success with the modifications President George W. Bush made to the Lacey Act, requiring that wood products show a legitimate chain of ownership. Prior to that, ethical companies could not compete with groups in China that would pay for illegal wood and then undercut U.S. prices in the end products.

The Brazilian state of Pará has the largest cattle herd in the Amazon biome. In 2009, the region’s largest slaughterhouse owners publicly committed to buying cattle only from those ranchers who ceased clearing rainforests and who registered their properties with the existing rural environmental registry. A new paper mapped the locations and land-use histories of each cattle rancher that sold to JBS, the world’s largest meatpacking company, before and after the agreements.

Before the agreements, only 2 percent of JBS’ suppliers had registered their properties so it was unknown if they were clearing land. Within five months of the cattle agreements, 60 percent of JBS suppliers had registered their properties and by 2013, that number had reached 96 percent. JBS suppliers registered their properties two-to-three years sooner than neighboring properties that did not sell to JBS, the analysis found.

The analysis concludes that supply-chain interventions could be a powerful way of reducing deforestation associated with commodities around the world.