Atmospheric carbon dioxide rise to remain too fast to track global climate targets in 2026 - Met Office

The latest forecast from Met Office scientists indicates that the rate of atmospheric carbon dioxide (CO₂) increase this year will remain too fast to meet climate targets outlined for limiting global warming to 1.5°C.

This rise in atmospheric carbon dioxide – the most important contributor to climate change - is despite a temporary small slowdown associated with natural climate fluctuations.

The annual average CO₂ concentration at the Mauna Loa Observatory, in Hawaii, is projected to rise by 2.37 ± 0.55 parts per million (ppm) in 2026 compared to 2025, reaching a new high of 429.4 ± 0.6 ppm.

Professor Richard Betts, who leads the production of the forecast, said: “The slight slowdown in the rate of CO₂ increase is only attributed to a temporary strengthening of natural carbon sinks – such as areas of tropical forest which draw down carbon dioxide- thanks to moderate La Niña conditions observed in late 2025 and early 2026. These conditions promote increased CO₂ absorption by plants and oceans, but the overall trend remains upward, with concentrations continuing to climb well above the trajectories required to cap global warming at 1.5°C compared with the period 1850-1900.”

Decades of measurements at Mauna Loa reveal an accelerating rise in atmospheric CO₂, primarily driven by human-caused emissions from fossil fuel burning and deforestation. While natural carbon sinks have removed a substantial amount of CO₂ from the atmosphere, concentrations have nonetheless surged by over 50% since the industrial revolution. In the absence of these natural processes, the increase would have been nearly double.