Several biomass groups sent a letter to newly sworn-in EPA Administrator Gina McCarthy on August 1, 2013, urging EPA to find that bioenergy and other biogenic sources of greenhouse gas emissions are carbon neutral for purposes of new greenhouse gas permitting requirements under EPA's Tailoring Rule. As we reported on July 19, 2013, last month the U.S. Court of Appeals for the District of Columbia vacated EPA's rule temporarily exempting these sources from the new greenhouse gas permitting requirements, which has created uncertainty for the industry going forward. In their letter to Administrator McCarthy, the groups argued, among other things, that there is a "significant and growing body of scientific findings concluding that carbon emissions from biomass do not introduce new carbon into the existing natural carbon cycle." The Biobased and Renewable Products Advocacy Group's July 19, 2013, memorandum is available online.