Europe should concentrate on making real emissions cuts in Europe, WWF has said as it released an annual assessment highlighting worsening difficulties with the assessment of carbon offset projects in the developing world. The study found no improvement in the work of evaluators assessing greenhouse gas offset projects in developing countries within the Clean Development Mechanism (CDM), noting that on a scale of A (best) to F (worst) the 'best' grade � achieved only by a single evaluator � was a D. The study analysed the reception by the CDM Executive Board of projects passed by evaluators. Once registered by the board, emissions saved by these projects are regarded as Certified Emissions Reductions (CERs) that can be offset against emissions in industrial countries. However, this year's study of more than 900 project proposals found that the board directly accepted only 36% of proposals (2009, 41%), demanded corrections to 57% of proposals (51%), and dismissed 7% (6%). In 2007 a study commissioned by WWF showed that many CDM projects are of questionable quality and do not lead to emission reductions. That report also called into question the role of the independent assessors. The key to certification is to verify whether CDM projects really need the additional revenues from CERs to be carried out � the so-called additionality criteria. In most cases the projects are not registered automatically because the board disagreed with the evaluators' assesments that CDM funding was necessary to the projects.