Global greenhouse gas emissions in selected countries 2000-2021

Greenhouse gas emissions for the world's major economies have followed very different patterns since the turn of the century. In 2000, the United States was the world's largest GHG emitter, but over the past two decades its emissions have fallen by more than 15 percent. In contrast, GHG emissions in China had soared more than 150 percent by the end of 2021, relative to 2000 levels, to a high of 13.7 billion metric tons of carbon dioxide equivalent (GtCO₂e). China was also the only major economy whose emissions were impacted by COVID-19-related lockdowns and restrictions.