PORTEL, Brazil — Over the past two decades, a new financial commodity known as carbon credits has become one of the world’s most important tools in the fight against climate change. …The Amazon rainforest…has increasingly drawn those pursuing carbon credits. …“carbon cowboys” have launched preservation projects generating carbon credits worth hundreds of millions of dollars; purchased by some of the world’s largest corporations. The projects have helped transform the Brazilian Amazon into an epicenter of a largely unaccountable global industry with sales of nearly $11 billion. But a Washington Post investigation shows that many of the private ventures have repeatedly and, authorities say, illegally laid claim to publicly protected lands, generating enormous profits from territory they have no legal right to and then failing to share the revenue with those who protected or lived on the land. The use of such lands to sell credits also contributes little to reducing carbon emissions. [full access to the story requires a Washington Post subscription]