Global emissions of carbon dioxide (CO2) – the main cause of global warming – increased by 3% last year, reaching an all-time high of 34 billion tonnes in 2011. In China, the world's most populous country, average emissions of CO2 increased by 9% to 7.2 tonnes per capita. China is now within the range of 6 to 19 tonnes per capita emissions of the major industrialised countries. In the European Union, CO2 emissions dropped by 3% to 7.5 tonnes per capita. The United States remain one of the largest emitters of CO2, with 17.3 tones per capita, despite a decline due to the recession in 2008-2009, high oil prices and an increased share of natural gas. These are the main findings of the annual report 'Trends in global CO2 emissions', released today by the European Commission's Joint Research Centre (JRC) and the Netherlands Environmental Assessment Agency (PBL).