Global emissions of carbon dioxide (CO2), considered the main cause of global warming, increased by 3% last year, reaching an all-time high of 34 billion tons in 2011.

China, the world’s most populous country, also leads the world in greenhouse gas emissions with nearly double the greenhouse gases of the US, and its average emissions of CO2 increased by 9% to 7.2 tons per capita. China is now within the range of 6 to 19 tons per capita emissions of the major industrialized countries. European Union, CO2 emissions dropped by 3% to 7.5 tons per capita while the United States dropped to 17.3 tons per capita, a decline due to a continuing recession and increased use of natural gas. 

Based on recent results from the Emissions Database for Global Atmospheric Research (EDGAR) and latest statistics on energy use and relevant activities such as gas flaring and cement production, the report shows that global CO2 emissions continued to grow in 2011, despite reductions in OECD countries.

Weak economic conditions, a mild winter, and less consumption due to high oil prices led to a decrease of 3% in CO2 emissions in the European Union and of 2% in both the United States and Japan. Emissions from OECD countries now account for only one third of global CO2 emissions – the same share as that of China and India combined, where emissions increased by 9% and 6% respectively in 2011. Economic growth in China led to significant increases in fossil fuel consumption driven by construction and infrastructure expansion. The growth in cement and steel production caused China’s domestic coal consumption to increase by 9.7%.

The 3% increase in global CO2 emissions in 2011 is above the past decade's average annual increase of 2.7%, with a decrease in 2008 and a surge of 5% in 2010. The top emitters contributing to the 34 billion tons of CO2 emitted globally in 2011 are: China (29%), the United States (16%), the European Union (11%), India (6%), the Russian Federation (5%) and Japan (4%).

An estimated cumulative global total of 420 billion tons of CO2 were emitted between 2000 and 2011 due to human activities, including deforestation. Scientific literature suggests that limiting the rise in average global temperature to 2°C above pre-industrial levels – the target requested by the UN climate – is possible only if cumulative CO2 emissions in the period 2000–2050 do not exceed 1,000 to 1,500 billion tons. If the current global trend of increasing CO2 emissions continues, cumulative emissions will surpass this limit within the next two decades.   

In developed countries, the upward trend is being mitigated by the expansion of renewable energy supplies, especially solar and biofuels. The global share of these so-called modern renewables, which exclude hydropower, is growing at an accelerated speed due to government subsidies and quadrupled from 1992 to 2011. This potentially represents about 0.8 billion tons of CO2 emissions avoided as a result of using renewable energy supplies in 2011, which is close to Germany's total CO2 emissions in 2011.

Report: "Trends in global CO2 emissions"