View source for Translations:Greenhouse gas emissions by the United States/12/en

Greenhouse gases vary in how long they remain in the atmosphere. Though methane and nitrous oxide are more potent greenhouse gasses than {{CO2}}, {{CO2}} is longer-lived, remaining in the atmosphere for centuries. The average {{CO2}} concentration in 2024 was over 424 parts per million (ppm), and exceeded 427 ppm in February 2025—each more than 50% higher than its pre-industrial level. Annual US national {{CO2}} emissions were exceeded only by those of China, which has four times the US population. Regardless of where emissions occur, the emitted gases spread around the world. This [[Anthropogenic hazard|anthropogenic]] (human-caused) increase in greenhouses gases has impacts on [[Weather|weather patterns]], [[drought]]s, [[heat wave]]s, [[wildfire]]s, [[ocean acidification]], [[sea level rise]], glacial melting, [[Global temperature record|average global temperatures]], [[extinction]] of species, and so forth.