A laboratory for 'green' beef. Photographer: Dado Galdieri/Bloomberg
A laboratory for 'green' beef. Photographer: Dado Galdieri/Bloomberg

In the ongoing pillage of tropical rainforests, villains are plenty. None has stoked imaginations like the Amazonian rancher. With his bulldozers and chainsaws, and herds that wander from horizon to horizon, the rainforest cattleman has emerged as Amazonia's public enemy No. 1, his ruin chronicled in titles like "The World is Burning," and "The Hamburger Connection." America's National Academy of Sciences is the latest to sound off.

Now the genre may be due for revision. Deforestation, though still high, has plunged across South America. It fell to a 25-year low last year, even as the Brazilian economy grew. Indonesia recently overtook Brazil as the world's leading forest cutter. A severe crackdown by public officials has helped. Authorities use real-time satellite data to pinpoint illegal cutting and forest fires, then dispatch patrols to swoop down on rogue herders and loggers. But more than a police story, this tropical turnaround tale is about smart policy and science allied with resourceful ranchers trying to make ends meet on one of the planet's most hostile landscapes.

Amazon herders have been notorious as among the world's most inefficient. In 1975, feeding a single cow in the world's largest rainforest basin took about three hectares (7.5 acres) of pasture. Because tropical soils were weak, growing the herd meant clearing more and more forest, a single acre of which harbored more species of flora and fauna than all of New England. Kerosene and a match did the rest. No nation has pumped more heat-trapping carbon dioxide into the air from slash-and-burn farming than Brazil.

It took a quarter-century, but eventually Big Beef got religion. The three biggest meat packing companies in Brazil pledged to boycott slaughterhouses that purchased beef from newly deforested land. After decades of haggling, Congress passed a new forestry code in 2012 that displeased almost everyone but also replaced a jungle of makeshift laws and decrees that had confounded farmers, forest police and environmental groups alike.

Less heralded is the revolution that Brazilian ranchland also has undergone. Squeezed by narrowing margins and a consumer backlash, Amazon herders reinvented their business to survive. They started rotating livestock to conserve pastures and planted improved strains of pasture grasses that kept the soil moist and grabbed crop-nurturing nitrogen from the air.

Today, ranchers are raising more beef than ever while also treading more lightly on the rainforest. In the last decade, while forest cutting fell 77 percent, the Amazon herd grew from 72 million to 78 million head, says Judson Valentim, an agronomist at Embrapa, a Brazilian agricultural research center. Profits increased as consumers agreed to pay more for "green" beef.

A lot is riding on Brazil's ranch revolution. With global poverty easing and the rise of middle classes across the emerging markets, the demand for food is expected to double by 2040. Tofu and meatless Mondays may be all the rage in San Francisco and Stockholm, but the upwardly mobile in Sao Paulo and Shenzhen want ribs and bacon.

But how to keep feeding a hungrier world without trashing the planet? Cue, again, the Brazilian cowboy. Recent research suggests that with the right technology, Brazil farmers and especially ranchers could increase production enough to meet future food demand without felling another hectare through 2040. According to Brazilian economist Bernardo Strassburg, head of the International Institute for Sustainability, Amazon ranchers are delivering only about a third of their potential. With the right inputs, Strassburg says, ranchers could graze more cattle on less land, and so avoid tossing 14.3 billion tons of carbon dioxide into the atmosphere through 2040. Strassburg says that's the equivalent of taking 100 million medium-sized cars off the American highways a year over the next three decades.

For years, the green lobby has said that any plan to rescue the world's rainforests is doomed as long as the people living there are condemned to backwardness and poverty. Now it's time to make good on the mantra. Ranchers need a hand, not the boot.

To contact the author of this article: Mac Margolis at macmargolis@terra.com.br.

To contact the editor responsible for this article: James Gibney at jgibney5@bloomberg.net.