The indicators in this report build on data provided regularly by member countries’ authorities using an OECD questionnaire, and on data available from other OECD and international sources. Some indicators were updated on the basis of international information available in April 2013 and on the basis of comments from national delegates received by February 2013. Nevertheless, due to delays in the production of environmental data in most countries, the most recent data for many of the parametres examined in this report is 2010.