Global mean surface temperature anomalies in 2023 and 2024 were the highest on the modern record. We quantify contributions to these anomalies from human activity, including the steep reduction in sulfur emissions from ships that began in 2020, and numerous natural factors. We attribute about 92% of the observed anomalies to a combination of various human-induced and natural factors, including important contributions from the reduction in marine sulfur emissions and the Indian Ocean Dipole.