Continued increase in atmospheric carbon dioxide exacerbated the 2022-2024 global temperature spike

Since spring 2023, global mean temperatures have surged, repeatedly surpassing historical monthly records. Although various causes have been proposed, their relative contributions remain unclear. Here we show that, using a novel attribution framework that combined a reduced complexity model with an observationally constrained statistical model, we recreated the annual global temperature for 1855-2024 with strong agreement with observations (r = 0.99). This approach captures key previous climate variations, including mid-20th century cooling, the 1998-2012 warming slowdown, and the recent temperature spike. We found that the 2022-2024 warming relative to the 2010-2021 level was caused mainly by an increase in atmospheric carbon dioxide (41%, 95% confidence interval: 35-50%) and a surge in the Atlantic Multidecadal Oscillation (39%, 23-50%), followed by the ascending solar cycle (9%, 1-19%). Our results suggest that the ongoing rise in carbon dioxide concentration has intensified recent warming. These coincidental peaks and troughs in anthropogenic and natural drivers may increase the likelihood of extreme temperature events.