Mauro Lucio Costa wanted to do the right thing for the world’s largest rainforest. For decades, the third-generation rancher in northern Brazil watched guiltily as his industry, feeding soaring global appetite for beef, razed ever more jungle. So, gradually he experimented with grasses and grazing techniques that today make his ranch one of the most efficient in Brazil. Costa became a model for those who believe beef can be raised profitably and sustainably – even in the Amazon. As a so-called “finishing farm,” Costa’s ranch is the last stop cattle make in a chain that begins with breeders and often includes stays on a progression of other properties before animals are grown and ready for slaughter. Eager to do more – and push others in the industry toward sustainability, too – Costa in 2017 decided to buy cattle only from breeders who could prove they weren’t ranching illegally cleared land. He asked a consultant to check suppliers’ farms for deforestation using satellite maps and a government list of embargoed properties.After only a year, though, his effort failed. Nearly half his cattle, Costa realized, came from suppliers who either had environmental violations or whose land titles and other paperwork were so questionable that he couldn’t be sure. To see his plan through, he said, he would have been unable to keep his herd populated and produce enough beef to make a profit.“I can’t sabotage my business for something no one else does,” Costa told Reuters, surrounded by pastures framed by towering rainforest. A wide-brimmed Resistol hat, a souvenir from trips to Texas, shielded his face from the tropical sun. His embossed belt buckle, also Texan, shone with his name and that of his ranch – Marupiara, an indigenous term that loosely means “place of happy hunting.” The admission, from a rancher so “green” he addressed attendees of a United Nations climate gathering last year, illustrates the hurdles to responsible development in the Amazon jungle.Costa’s effort was entangled by snags that have long hindered order in the vast, unruly region – from lax land registries to weak law enforcement to the opaque workings of Brazil’s beef business, in which cattle, with little or no tracking by government or industry, are reared and fattened on a succession of ranches. It can be impossible for ranchers like Costa to know for certain where their animals hail from.In many other major producers, like the United States, cattle move around less, living longer on single ranches and subsisting more on grains and prepared feeds. But Brazil’s cattle remain mostly grass-fed, using more pasture and leading ranches to specialize in particular stages of the animals’ growth.While Brazilian law in theory makes it a crime to raise beef on illegally cleared woodland, few mechanisms exist to help buyers identify cattle’s origins. Livestock, like money, are often laundered, passing from pastures that violate environmental laws, into the legal supply chain, and on to supermarkets and dinner tables worldwide.“There is a huge hole in the system,” said Paulo Barreto, one of Brazil’s leading researchers on land use in the Amazon. “No meat processor can say their cattle are deforestation-free.”The Amazon, a jungle larger than Western Europe, is a crucial natural bulwark against climate change. It’s a major source of the world’s oxygen and fresh water, its vegetation a giant filter for greenhouse gases.Although more than 80% of the original Amazon still stands, deforestation has accelerated in recent years as loggers, soy farmers and cattle ranchers, spurred by ravenous global demand, hack and burn deeper into the rainforest.In addition to market forces fueling the devastation, President Jair Bolsonaro, a far-right populist, has reversed policies that prevented deforestation, slashing budgets of agencies that for decades fought unauthorized clearing.Emboldened by the changes, Brazilians last year felled and burned rainforest equivalent in size to Lebanon, the largest clearing in more than a decade. This year, data suggest deforestation and fires in the Amazon continue apace.International outrage is mounting.VF Corp, the US company that owns apparel brands including Vans, Timberland, and The North Face, said last year it would stop buying Brazilian leather. In May, British supermarkets threatened to boycott Brazilian products. In June, a group of major European investors said it was considering divesting its Brazilian holdings, including government bonds, if Bolsonaro doesn’t change course.