A new report finds the most common system for trading carbon emissions, which allows rich European countries to continue polluting while also investing in environmental projects in developing countries, has major flaws. The report finds that as many as a third of the “green” projects approved in India are actually regular commercial ventures, wrongly approved by fraudulent middlemen. Those concerns led British airline Easyjet to cut out the middleman entirely, buying U.N.-backed carbon credits on the open market and selling them directly to passengers. The Guardian reports that scientists have doubts about how effective carbon credits actually are. Widely-used carbon offset schemes, such as tree planting, may ironically increase global warming by trapping heat, the newspaper reports.