Global emissions of carbon dioxide from energy use rose 1.4 percent to 31.6 gigatons in 2012, setting a record and putting the planet on course for temperature increases well above international climate goals, the International Energy Agency said in a report issued Monday.
The agency said continuing that pace could mean a temperature increase over pre-industrial times of as much as 5.3 degrees Celsius, which IEA chief economist Fatih Birol warned "would be a disaster for all countries."
"This puts us on a difficult and dangerous trajectory," Birol said. "If we don't do anything between now and 2020, it will be very difficult because there will be a lot of carbon already in the atmosphere and the energy infrastructure will be locked in."
The energy sector accounts for more than two-thirds of greenhouse gas emissions, so "energy has a crucial role to play in tackling climate change," the IEA said. Its report urged nations to take four steps, including aggressive energy-efficiency measures, by 2015 to keep alive any hope of limiting climate change to 2 degrees Celsius.
The United States was one of the few relatively bright spots in the report. Switches from coal to shale gas accounted for about half the nation's 3.8 percent drop in energy-related emissions, which fell for the fourth time in the past five years, dipping to a level last seen in the 1990s. The other factors were a mild winter, declining demand for gasoline and diesel, and the increasing use of renewable energy.
Emissions also fell in Europe. But they rose 3.8 percent in China. That was one of the slowest increases in the past decade, and half of 2011's rate of increase. The level of carbon dioxide emissions per unit of electricity generation has fallen about 17 percent in China. But China remains the largest contributor of carbon dioxide into the atmosphere, with about a quarter of global emissions.
Japan's emissions jumped 5.8 percent as the country imported and burned large amounts of liquefied natural gas and coal to compensate for the loss of electricity production from nuclear plants that have been idle since a tsunami damaged the Fukushima No. 1 nuclear complex.
Emissions also climbed in developing countries outside the Organization of Economic Cooperation and Development, especially in the oil-rich Middle East where fuel prices are heavily subsidized.
The IEA mapped a way for countries and companies to contain increases in global temperatures. It urged them to implement aggressive energy-efficiency measures; limit the output of inefficient coal plants and mandate that all future coal plants be highly efficient supercritical ones; reduce the release of methane (a potent greenhouse gas) in oil and gas operations; and phase out fossil-fuel subsidies.
The agency estimated that the release of natural gas, or methane, during upstream oil and gas operations accounted for about half of all methane emissions by the oil and gas industry. Large aging pipeline networks in Europe, Russia and the U.S. also account for a large amount, the IEA said.