Hot droughts in the Amazon provide a window to a future hypertropical climate

Journal Article · Wed Dec 10 00:00:00 EST 2025 · Nature (London)

DOI:https://doi.org/10.1038/s41586-025-09728-y· OSTI ID:3017041

Chambers, Jeffrey Q. ^[1]; Nogueira Lima, Adriano José ^[2]; Pastorello, Gilberto Z. ^[3]; Gimenez, Bruno Oliva ^[4]; Meng, Lin ^[5]; Dyer, Lee A. ^[6]; Feng, Yanlei ^[7]; Santos da Silva, Cristina ^[2]; Costa de Oliveira, Regison ^[2]; Weber, Anna ^[8]; Koven, Charlie D. ^[3]; Negrón-Juárez, Robinson ^[3]; Spanner, Gustavo C. ^[2]; Gaui, Tatiana D. ^[2]; Fontes, Clarissa G. ^[9]; de Araújo, Alessandro C. ^[10]; McDowell, Nate G. ^[11]; Leung, Lai-Yung Ruby ^[11]; Marra, Daniel Magnabosco ^[12]; Warren, Jeffrey ^[13] ; Celestina Souza, Daisy ^[2]; Wright, Cynthia L. ^[13]; Jardine, Kolby ^[14]; Longo, Marcos ^[15]; Xu, Chonggang ^[16]; Fine, Paul V. A. ^[8]; Fisher, Rosie A. ^[17]; Tomasella, Javier ^[18]; dos Santos, Joaquim ^[2]; Higuchi, Niro ^[2]

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1. University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus (Brazil)
2. Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus (Brazil)
3. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
4. University of California, Berkeley, CA (United States); Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus (Brazil)
5. Vanderbilt University, Nashville, TN (United States)
6. University of Nevada, Reno, NV (United States)
7. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
8. University of California, Berkeley, CA (United States)
9. BeZero Carbon, London (United Kingdom)
10. Embrapa Amazônia Oriental, Belém (Brazil)
11. Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
12. Julius Kühn Institute (JKI), Quedlinburg (Germany); Max Planck Institute for Biogeochemistry, Jena (Germany)
13. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
14. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus (Brazil)
15. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Instituto Nacional de Pesquisas Espaciais (INPE), Cachoeira Paulista (Brazil)
16. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
17. Center for International Climate Research (CICERO), Oslo (Norway)
18. Instituto Nacional de Pesquisas Espaciais (INPE), Cachoeira Paulista (Brazil)

Tropical forests represent the warmest and wettest of Earth’s biomes, but with continued anthropogenic warming, they will be pushed to climate states with no current analogue. Droughts in the tropics are already becoming more intense as they occur at successively higher temperatures. Here, in this study, we synthesize multiple datasets to assess the effects of hot droughts on a central Amazon forest. First, a more than 30-year record of annually resolved forest demographic data from a selective logging experiment showed higher tree mortality during intense droughts, particularly among fast-growing pioneer species with low wood density. Second, analysis of ecophysiological field measurements from the 2015 and 2023 El Niño droughts identified a soil moisture threshold beyond which transpiration rates rapidly declined. As rainless days beyond this threshold continued, drought conditions intensified, increasing the potential for tree mortality from hydraulic failure and carbon starvation. Third, analyses from the Coupled Model Intercomparison Project Phase 6 demonstrated that under high-emission scenarios, a large area of tropical forest will shift to a hotter ‘hypertropical’ climate by 2100. Last, under a hypertropical climate, temperature and moisture conditions during typical dry season months will more frequently exceed identified drought mortality thresholds, elevating the risk of forest dieback. Present-day hot droughts are harbingers of this emerging climate, offering a window for studying tropical forests under expected extreme future conditions.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: National Science Foundation (NSF); USDOE Office of Science (SC), Biological and Environmental Research (BER)
• Grant/Contract Number: 89233218CNA000001; AC02-05CH11231; AC05-00OR22725; AC05-76RL01830
• Other Award/Contract Number: DGE-2244337
• OSTI ID: 3017041
• Alternate ID(s): OSTI ID: 3016924
• Report Number(s): PNNL-SA--215954
• Journal Information: Nature (London), Journal Name: Nature (London) Journal Issue: 8099 Vol. 649; ISSN 1476-4687; ISSN 0028-0836
• Publisher: Nature Publishing Group
• Country of Publication: United States
• Language: English

Related Subjects

drought
rainforest
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