Two studies commissioned by the European Environmental Bureau (EEB), Transport and Environment (T&E) and Birdlife International show that "Europe has a major carbon accounting problem, threatening the credibility of two flagship EU environmental policies: the Renewable Energy Directive (RED) and the Emissions Trading Scheme". One study mentions that biomass energy can have "variable climate mitigation potential, depending on the timeframe considered and the source of the biomass". Land conversion can result in carbon stock changes; for example, removing vegetation and ploughing the soils to grow bio-energy feedstocks can lead to GHG (greenhouse gas) emissions. Another study shows that "growing biofuels on agricultural land results in the conversion of forests and other natural areas into crop land to replace the agricultural lands lost to biofuel production." There is an assumption that biofuels are carbon neutral. But this may not necessarily be the case, because the carbon that would have been absorbed by vegetation on the land is often overlooked. Unless a number of urgent measures are taken, the EU's renewable energy policy aimed to mitigate climate change, may likely lead to an increase in carbon emissions. A "right carbon accounting" is essential. Details of the report can be obtained from the bioenergy website (URL above).