Carbon Emissions on the Rise But Policies Growing Too

In 2007, carbon emissions from fossil fuel combustion worldwide reached an estimated 8.2 billion tons, which was 2.8 percent more than in 2006—and 22 percent above the total in 2000.¹ The United States and Europe accounted for roughly 4 and 3 percent, respectively, of the growth during this decade.² India contributed 8 percent, and China, a staggering 57 percent.³ Despite the rapid increase, China’s 18.3 share of global fossil fuel emissions remained slightly behind the U.S. share (19.5 percent).⁴ Per capita emissions in the developing world remain well below those in industrial countries.⁵ (See Figure 1 and Table 1.)

Coal, oil, and natural gas are burned to produce electricity, to power engines, and to feed industrial processes. When burned, the carbon contained in these fuels is converted to carbon dioxide (CO₂), which is a natural component of Earth’s atmosphere. CO₂ traps heat that would otherwise radiate into outer space, thereby keeping Earth’s temperature within a habitable range.⁶ But emissions from human activities have greatly increased the stock of carbon dioxide in the atmosphere. The additional gas is trapping more heat, raising the average global temperature and changing the climate.⁷ Fossil fuels account for about 74 percent of all CO₂ emissions and for roughly 57 percent of all greenhouse gas emissions.⁸ (See Figure 2.)

The combustion of coal typically releases 1.8 times as much carbon dioxide per unit of energy as natural gas does and 1.3 times as much as oil.⁹ But since more oil than coal is used, total emissions from these two fossil fuels are similar.¹⁰