China led a rise in global carbon dioxide emissions to a record high in 2012, more than offsetting falls in the United States and Europe, the International Energy Agency (IEA) said on Monday.
Worldwide CO2 emissions rose by 1.4 percent to 31.6 billion tons, according to estimates from the Paris-based IEA.
China is the biggest emitter and made the largest contribution to the global rise, spewing out an additional 300 million tons. But the gain was one of the lowest China has seen in a decade, reflecting its efforts to adopt renewable sources and improve energy efficiency.
In the United States, a switch from coal to gas in power generation helped reduce emissions by 200 million tons, bringing them back to the level of the mid-1990s.
Even though the use of coal increased in some European countries last year due to low prices, emissions in Europe declined by 50 million tons because of the economic slowdown, growth in renewables, and emissions caps on industrial and power companies, the IEA said.
Japan's CO2 emissions increased by 70 million tons, as efforts to improve energy efficiency failed to offset increasing use of fossil fuels after the Fukushima nuclear accident in 2011.
Scientists say global average temperature rise needs to be limited to below 2 degrees Celsius this century to prevent devastating climate effects like crop failure and melting glaciers.
That would only be possible if emission levels are kept to around 44 billion tons of CO2 equivalent by 2020.
However, the IEA said the data shows the world is on a path to an average temperature rise of between 3.6 and 5.3 degrees Celsius.