Global carbon dioxide emissions from fossil fuels are projected to fall in 2026, the first annual decline in five years, according to the Global Carbon Budget, an assessment produced by more than 140 researchers and published in Nature Climate Change. The study expects emissions to reach 38.2 gigatonnes of CO2 this year, a drop of 0.4 per cent from the previous year. The main driver is an energy shock linked to the war involving Iran, which began in February 2026.
The conflict prompted Iran to blockade the Strait of Hormuz, a waterway through which roughly 20 per cent of world oil and liquefied natural gas trade passes. The disruption sent oil prices sharply higher, and petrol and household gas bills remain elevated. Higher costs have reduced fuel consumption, with oil-related emissions projected to fall by 1.9 per cent in 2026. Coal use, however, is expected to rise by 0.6 per cent, partly offsetting the decline in oil.
China, the world's largest emitter, is projected to see its emissions fall by 0.9 per cent in 2026. The authors also point to a broader shift in energy policy. Countries are turning to alternative fuels in an effort to strengthen energy security, and the report credits the growth of electric vehicles, solar and wind power with helping to hold emissions down. Those technologies are expected to offset between 64 and 79 per cent of emissions that would otherwise arise from growth in energy demand through 2028.
Robbie Andrew of the Center for International Climate Research (CICERO) in Oslo and Corinne Le Quéré of the University of East Anglia in the United Kingdom are co-authors of the report. Their analysis places the expected 2026 decline in historical context. The Covid-19 pandemic cut global emissions by around 6 per cent in 2020, while the 2009 financial crisis reduced them by about 2 per cent. The current fall is far smaller than either of those episodes.
The researchers caution that the dip may prove to be a temporary blip rather than a lasting turn. Emissions could rebound if oil returns to its pre-conflict price, and the duration of the energy shock remains unknown. Governments may also reconsider fossil fuel subsidies as they respond to the crisis, a decision that would influence whether the decline holds beyond this year.