In 2018, US CO2 emissions rose 2.7% to 5.27 billion metric tons. However, CO2 emissions have declined in six of the past 10 years and remain 12% lower than their 2005 peak despite the economy being 25% larger in inflation-adjusted terms. This is partly because creating a million dollars of GDP requires 29% less CO2 than in 2005, and partly because coal use has plunged by more than 33%.