The 2023–2024 El Niño as a Preview of Future Tropical Forest Climate

Tropical forests are an important component of the global carbon cycle. Increasingly frequent droughts and heatwaves are undermining their resilience, with far-reaching impacts on local livelihoods and on regional and global hydrological cycles. El Niño events, recurring climate patterns that lead to dry and hot conditions across multiple tropical regions, have always influenced these dynamics, but the 2023–2024 El Niño produced extreme droughts and heatwaves that exceeded the typical El Niño footprint. Here, we place the 2023–2024 El Niño in both past (2000–2024) and future (2025–2100) climatic contexts across pantropical forests. We assess its climatic magnitude using ensembles of reanalyses, satellite climate products, and Earth System Models. Climate anomalies over 2000–2024 show that three quarters of pantropical forests experienced, on average, 6 months of compound droughts and heatwaves during 2023–2024. Based on future climate projections, most tropical forest regions will reach high probabilities of experiencing 2023–2024-like temperatures on an annual basis, while the probability of similar droughts is expected to increase mostly in Amazonian forests. These results indicate that the 2023–2024 El Niño may have presented a preview of future tropical forest conditions, which can only be prevented by rapid and drastic reductions in global greenhouse gas emissions.