Global carbon dioxide emissions from fossil fuels and industry totaled billion metric tons (GtCO₂) in 2025. Emissions are projected to have risen percent in 2025 to reach a record high of GtCO₂. Since 1990, global CO₂ emissions have increased by more than percent.
Who are the biggest emitters?
The biggest contributor to global GHG emissions is China, followed by the United States. China wasn't always the world's biggest emitter, but rapid economic growth and industrialization in recent decades have seen emissions there soar. Since 1990, CO₂ emissions in China have increased by almost percent. By comparison, U.S. CO₂ emissions have fallen by percent. Nevertheless, the North American country remains the biggest carbon polluter in history.
Global events cause emissions to drop
The outbreak of COVID-19 caused global CO₂ emissions to plummet some percent in 2020 as a result of lockdowns and other restrictions. However, this wasn't the only time in recent history when a major global event caused emissions reductions. For example, the global recession resulted in CO₂ levels to fall by almost percent in 2009, while the recession in the early 1980s also had a notable impact on emissions. On a percentage basis, the largest annual reduction was at the end of the Second World War in 1945, when emissions decreased by percent.