Leadership Needed by Biggest Emitters

Carbon Dioxide Emissions from Fossil Fuel Burning and Consumption for 2008


Dividing the Global Carbon Budget

During the 20th century, a small number of rich countries produced the vast majority of the world’s carbon emissions. To limit future temperature increase to 2°C, emissions must peak soon, as shown by the blue line on the right. The area under that blue line can be thought of as the world’s “carbon budget.” On their current course, rapidly developing nations could consume all of the carbon budget by 2030 – even if wealthy nations were to entirely eliminate their emissions over the same period.


It is said that climate change is a global problem. This is true in the sense that the atmosphere is a global commons that does not care where emissions come from, only their amount. But of the world’s 195 nations, just 10 produce more than 60 percent of total emissions. Emissions from all nations matter, but the largest emitters must lead the drive towards a clean energy future, recognizing that low-carbon growth is the key to future prosperity.

The two biggest greenhouse gas polluters are the United States and China. One of the first populous countries to industrialize, the U.S. was the leading producer of CO2 for all of the 20th century, and thus is responsible for the biggest share (about 28 percent) of cumulative heat- trapping emissions already in the atmosphere.

Due to its rapid modernization, and the doubling of its coal burning between 1998 and 2008, China recently surpassed the U.S. to become the world’s largest emitter. Nonetheless, in a country of 1.3 billion people, China’s per capita emissions are just one-third of those in the United States.

The climate challenge cannot be resolved without the concerted, cooperative efforts of these two nations.

Due in part to the oil price shock of 2008 and the following recession, U.S. emissions have fallen by 9 percent since 2005. But China’s emissions have continued their rapid rise. About 70 percent of China’s CO2 comes from burning coal, but the country is also now the world’s largest automobile market and by far the world’s largest producer of cement and steel. China has begun to diversify its energy mix with natural gas pipelines, nuclear power plants, liquefied natural gas imports, and an aggressive move into wind and solar power.

China and India: Emerging Giants of the World Economy

Historically, wealthy developed nations in Europe and North America have produced more than 60 percent of global emissions. During the last decade, however, developing nations have closed the gap, and their energy consumption is still rapidly growing. At the peak of its industrialization, the U.S. added 200 gigawatts of power generation over a 20-year period. China – which already burns 45 percent of the world’s coal – has been adding a comparable amount every few years.

Although per capita emissions in India, China, and other rapidly industrializing countries will remain far below those in Europe and America for years to come, these emerging giants will account for nearly 75 percent of primary energy growth by 2030. In that year, China and India may consume nearly half of global oil exports.

The energy security and climate implications are sobering: In the absence of prompt action to change the emissions trajectory, developing nations could consume the entire world’s 2°C “carbon budget” by 2030. To avoid a climate crisis, all nations must immediately draw up and adopt effective climate policies.