Originating in the equatorial Pacific, the El Niño–Southern Oscillation (ENSO) has highly consequential global impacts, motivating the need to understand its responses to anthropogenic warming. In this Review, we synthesize advances in observed and projected changes of multiple aspects of ENSO, including the processes behind such changes. As in previous syntheses, there is an inter-model consensus of an increase in future ENSO rainfall variability. Now, however, it is apparent that models that best capture key ENSO dynamics also tend to project an increase in future ENSO sea surface temperature variability and, thereby, ENSO magnitude under greenhouse warming, as well as an eastward shift and intensification of ENSO-related atmospheric teleconnections — the Pacific–North American and Pacific–South American patterns. Such projected changes are consistent with palaeoclimate evidence of stronger ENSO variability since the 1950s compared with past centuries. The increase in ENSO variability, though underpinned by increased equatorial Pacific upper-ocean stratification, is strongly influenced by internal variability, raising issues about its quantifiability and detectability. Yet, ongoing coordinated community efforts and computational advances are enabling long-simulation, large-ensemble experiments and high-resolution modelling, offering encouraging prospects for alleviating model biases, incorporating fundamental dynamical processes and reducing uncertainties in projections.
Under anthropogenic warming, the majority of climate models project faster background warming in the eastern equatorial Pacific compared with the west. The observed equatorial Pacific surface warming pattern since 1980, though opposite to the projected faster warming in the equatorial eastern Pacific, is within the inter-model range in terms of sea surface temperature (SST) gradients and is subject to influence from internal variability.
El Niño–Southern Oscillation (ENSO) rainfall responses in the equatorial Pacific are projected to intensify and shift eastward, leading to an eastward intensification of extratropical teleconnections.
ENSO SST variability and extreme ENSO events are projected to increase under greenhouse warming, with a stronger inter-model consensus in CMIP6 compared with CMIP5. However, the time of emergence for ENSO SST variability is later than that for ENSO rainfall variability, opposite to that for mean SST versus mean rainfall.
Future ENSO change is likely influenced by past variability, such that quantification of future ENSO in the only realization of the real world is challenging.
Although there is no definitive relationship of ENSO variability with the mean zonal SST gradient or seasonal cycle, palaeoclimate records suggest a causal connection between vertical temperature stratification and ENSO strength, and a greater ENSO strength since the 1950s than in past centuries, supporting an emerging increase in ENSO variability under greenhouse warming.
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Philander et al. Unstable air-sea interactions in the tropics. J. Atmos. 41, 604–613 (1984).
Ropelewski, C. F. & Halpert, M. S. Global and regional scale precipitation patterns associated with the El Niño/Southern Oscillation. Mon. Weather Rev. 115, 1606–1626 (1987).
McPhaden et al. ENSO as an integrating concept in earth science. Science 314, 1740–1745 (2006).
L’Heureux, M. L. et al. Observing and predicting the 2015/16 El Niño. Bull. Am. Meteorol. Soc. 98, 1363–1382 (2017).
Santoso, A., McPhaden, M. J. & Cai, W. The defining characteristics of ENSO extremes and the strong 2015/16 El Niño. Rev. Geophys. 55, 1079–1129 (2017).
Bjerknes, J. Atmospheric teleconnections from the equatorial Pacific. Mon. Weather. Rev. 97, 163–172 (1969).
Cai, W. et al. Climate impacts of the El Nino–Southern Oscillation on South America. Nat. Rev. Earth Environ. 1, 215–231 (2020).
Ashok, K., Behera, S. K., Rao, S. A., Weng, H. Y. & Yamagata, T. El Niño Modoki and its possible teleconnection. J. Geophys. Res. 112, C11007 (2007). Defines a type of El Niño with maximum SST anomaly in the equatorial CP atmospheric teleconnection different from El Niño with anomaly centre in the equatorial EP.
Valle, C. A. et al. The impact of the 1982–1983 El Niño-Southern Oscillation on seabirds in the Galapagos Islands, Ecuador. J. Geophys. Res. Oceans 92, 14,437–14,444 (1987).
Holbrook, N. J. et al. Keeping pace with marine heatwaves. Nat. Rev. Earth Environ. 1, 482–493 (2020).
Glynn, P. W. & de Weerdt, W. H. Elimination of two reef-building hydrocorals following the 1982–83 El Niño. Science 253, 69–71 (1991).
Jonkman, S. N. Global perspectives on loss of human life caused by floods. Nat. Hazards 34, 151–175 (2005).
Kunii, O., Nakamura, S., Abdur, R. & Wakai, S. The impact on health and risk factors of the diarrhoea epidemics in the 1998 Bangladesh floods. Public Health 116, 68–74 (2002).
del Ninno, C. & Dorosh, P. A. Averting a food crisis: private imports and public targeted distribution in Bangladesh after the 1998 flood. Agric. Econ. 25, 337–346 (2001).
McPhaden, M. J., Santoso, A., & Cai, W. (eds) El Niño Southern Oscillation in a Changing Climate Vol. 253 (Wiley, 2020).
Collins, M. et al. The impact of global warming on the tropical Pacific Ocean and El Niño. Nat. Geosci. 3, 391–397 (2010).
Cai, W. et al. ENSO and greenhouse warming. Nat. Clim. Change 5, 849–859 (2015).
Jin, F.-F. & Neelin, J. D. Modes of interannual tropical ocean-atmosphere interaction — A unified view. Part I: Numerical results. J. Atmos. 50, 3477–3503 (1993).
An, S.-I. & Jin, F.-F. An eigen analysis of the interdecadal changes in the structure and frequency of ENSO mode. Geophys. Res. Lett. 27, 1573–1576 (2000).
Fedorov, A. V. & Philander, S. G. A stability analysis of tropical ocean-atmosphere interactions: Bridging measurements and theory for El Niño. J. Clim. 14, 3086–3101 (2001).
IPCC. Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (eds Stocker, T. F. et al) 1535 pp (Cambridge Univ. Press, 2013).
IPCC. Global Warming of 1.5 °C. An IPCC Special Report on the impacts of global warming of 1.5 °C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty (eds Masson-Delmotte, V. et al) https://www.ipcc.ch/sr15/ (2018).
Meehl, G. A., Brantstator, G. W. & Washington, W. M. Tropical Pacific interannual variability and CO2 climate change. J. Clim. 6, 42–63 (1993).
Tett, S. Simulation of El Niño-Southern Oscillation-like variability in a global AOGCM and its response to CO2 increase. J. Clim. 8, 1473–1502 (1995).
Power, S. B., Delage, F., Chung, C., Kociuba, G. & Keay, K. Robust twenty-first century projections of El Niño and related precipitation variability. Nature 502, 541–545 (2013).
Yun, K. S. et al. Increasing ENSO–rainfall variability due to changes in future tropical temperature–rainfall relationship. Commun. Earth Environ. 2, 43 (2021).
Cai, W. et al. Increasing frequency of extreme El Niño events due to greenhouse warming. Nat. Clim. Change 4, 111–116 (2014).
Wang, G. et al. Continued increase of extreme El Niño frequency long after 1.5 C warming stabilization. Nat. Clim. Change 7, 568–572 (2017). Finds that extreme El Niño frequency continues to increase for up to a century after global warming is halted at 1.5 °C above pre-industrial level.
Cai, W. et al. More extreme swings of the South Pacific convergence zone due to greenhouse warming. Nature 488, 365–369 (2012).
Brown, J. R. et al. South Pacific Convergence Zone dynamics, variability and impacts in a changing climate. Nat. Rev. Earth Environ. 1, 530–543 (2020).
Santoso, A. et al. Late-twentieth-century emergence of the El Niño propagation asymmetry and future projections. Nature 504, 126–130 (2013).
Cai, W. et al. Increased frequency of extreme La Niña events under greenhouse warming. Nat. Clim. Change 5, 132–137 (2015).
Grothe, P. R. et al. Enhanced El Niño–Southern oscillation variability in recent decades. Geophys. Res. Lett. 47, e2019GL083906 (2020). Shows decreased ENSO variance 3,000–5,000 years ago and ENSO strengthening in the last five decades, using a new ensemble of fossil coral oxygen isotope records from the central equatorial Pacific.
McGregor, S., Timmermann, A. & Timm, O. A unified proxy for ENSO and PDO variability since 1650. Clim. Past. 6, 1–17 (2010).
McGregor, H. et al. A weak El Niño/Southern Oscillation with delayed seasonal growth around 4,300 years ago. Nat. Geosci. 6, 949–953 (2013).
Cai, W. et al. Increased variability of eastern Pacific El Niño under greenhouse warming. Nature 564, 201–206 (2018).
Luo, J.-J., Wang, G. & Dommenget, D. May common model biases reduce CMIP5’s ability to simulate the recent Pacific La Niña-like cooling? Clim. Dyn. 50, 1335–1351 (2018).
Coats, S. & Karnauskas, K. B. A role for the equatorial undercurrent in the ocean dynamical thermostat. J. Clim. 31, 6245–6261 (2018).
Seager, R. et al. Strengthening tropical Pacific zonal sea surface temperature gradient consistent with rising greenhouse gases. Nat. Clim. Change 9, 517–522 (2019).
Chung, E. S. et al. Reconciling opposing Walker circulation trends in observations and model projections. Nat. Clim. Change 9, 405–412 (2019). Shows a reduced strengthening of the Pacific Walker circulation during recent decades in satellite observations compared with reanalysis products and a dominant role of internal variability in the strengthening.
Cai, W. et al. Pantropical climate interactions. Science 363, eaav4236 (2019).
Cai, W. et al. Butterfly effect and a self-modulating El Niño response to global warming. Nature 585, 68–73 (2020). Demonstrates that ENSO exhibits a self-regulating behaviour such that future variability is shaped by its past, thus, modulating the effect of greenhouse forcing.
Maher, N., Matei, D., Milinski, S. & Marotzke, J. ENSO change in climate projections: Forced response or internal variability? Geophys. Res. Lett. 45, 11,390–11,398 (2018).
Zheng, X.-T., Hui, C. & Yeh, S. W. Response of ENSO amplitude to global warming in CESM large ensemble: uncertainty due to internal variability. Clim. Dyn. 50, 4019–4035 (2018).
Ng, B., Cai, W., Cowan, T. & Bi, D. Impacts of low-frequency internal climate variability and greenhouse warming on El Niño–Southern Oscillation. J. Clim. 34, 2205–2218 (2021).
Fu, C. & Fletcher, J. O. Two patterns of equatorial warming associated with El Niño. Chin. Sci. Bull. 30, 1360–1364 (1985). Shows that there are two types of equatorial warming associated with El Niño.
Fu, C., Diaz, H. F. & Fletcher, J. O. Characteristics of the response of sea surface temperature in the central Pacific associated with warm episodes of the Southern Oscillation. Mon. Weather Rev. 114, 1716–1738 (1986).
Capotondi, A. et al. Understanding ENSO diversity. Bull. Am. Meteorol. Soc. 96, 921–938 (2015).
Capotondi, A., Wittenberg, A. T., Kug, J.-S., Takahashi, K. & McPhaden, M. J. ENSO Diversity, in El Niño Southern Oscillation in a Changing Climate (eds McPhaden, M. J., Santoso, A. & Cai, W.) (AGU, 2020).
Takahashi, K. & Dewitte, B. Strong and moderate nonlinear El Niño regimes. Clim. Dyn. 46, 1627–1645 (2016).
Timmermann, A. et al. El Niño–southern oscillation complexity. Nature 559, 535–545 (2018).
Dommenget, D., Bayr, T. & Frauen, C. Analysis of the non-linearity in the pattern and time evolution of El Niño Southern Oscillation. Clim. Dyn. 40, 2825–2847 (2013).
Takahashi, K., Montecinos, A., Goubanova, K. & Dewitte, B. ENSO regimes: Reinterpreting the canonical and Modoki El Niño. Geophys. Res. Lett. 38, L10704 (2011).
Karamperidou, C., Jin, F.-F. & Conroy, J. L. The importance of ENSO nonlinearities in tropical Pacific response to external forcing. Clim. Dyn. 49, 2695–2704 (2017).
Philip, S. Y. & van Oldenborgh, G. J. Shifts in ENSO coupling processes under global warming. Geophys. Res. Lett. 33, L11704 (2006).
Jin, F.-F., Kim, S. T. & Bejarano, L. A coupled-stability index for ENSO. Geophys. Res. Lett. 33, L23708 (2006).
Kim, S. T. & Jin, F.-F. An ENSO stability analysis. Part II: results from the twentieth and twenty-first century simulations of the CMIP3 models. Clim. Dyn. 36, 1609–1627 (2011).
Carréric, A. et al. Change in strong Eastern Pacific El Niño events dynamics in the warming climate. Clim. Dyn. 54, 901–918 (2020).
Dewitte, B., Yeh, S.-W., Moon, B.-K., Cibot, C. & Terray, L. Rectification of the ENSO variability by interdecadal changes in the equatorial background mean state in a CGCM simulation. J. Clim. 20, 2002–2021 (2007).
Timmermann, A. et al. Increased El Niño frequency in a climate model forced by future greenhouse warming. Nature 398, 694–697 (1999).
Thual, S., Dewitte, B., An, S.-I. & Ayoub, N. Sensitivity of ENSO to stratification in a recharge–discharge conceptual model. J. Clim. 4, 4331–4348 (2011). Refines the theoretical framework showing intensified ocean–atmosphere coupling as the mean upper-ocean stratification increases.
Zhang, Q., Guan, Y. & Yang, H. ENSO amplitude change in observation and coupled models. Adv. Atmos. Sci. 25, 361–366 (2008).
Kim, S. T. et al. Response of El Niño sea surface temperature variability to greenhouse warming. Nat. Clim. Change 4, 786–790 (2014).
Geng, T., Cai, W. & Wu, L. Two types of ENSO varying in tandem facilitated by nonlinear atmospheric convection. Geophys. Res. Lett. 47, e2020GL088784 (2020).
Capotondi, A. & Sardeshmukh, P. D. Is El Niño really changing? Geophys. Res. Lett. 44, 8548–8556 (2017).
Wang, B. et al. Historical change of El Niño properties sheds light on future changes of extreme El Niño. Proc. Natl Acad. Sci. USA 116, 22512–22517 (2019).
Kennedy, J. J. A review of uncertainty in in situ measurements and data sets of sea surface temperature. Rev. Geophys. 52, 1–32 (2014).
Li, J. et al. El Niño modulations over the past seven centuries. Nat. Clim. Change 3, 822–826 (2013).
Liu, Y. et al. Recent enhancement of central Pacific El Niño variability relative to last eight centuries. Nat. Commun. 8, 15386 (2017).
Cobb, K. M. et al. Highly variable El Niño–southern oscillation throughout the Holocene. Science 339, 67–70 (2013).
Karamperidou, C. et al. ENSO in a Changing Climate: Challenges, Paleo-Perspectives, and Outlook, in El Niño Southern Oscillation in a Changing Climate (eds McPhaden, M. J., Santoso, A. & Cai, W.) (AGU, 2020).
Freund, M. et al. Higher frequency of Central Pacific El Niño events in recent decades relative to past centuries. Nat. Geosci. 12, 450–455 (2019).
Rayner, N. A. et al. Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century. J. Geophys. Res. 108, 4407 (2003).
Huang, B. et al. Extended reconstructed sea surface temperature, version 5 (ERSSTv5): upgrades, validations, and intercomparisons. J. Clim. 30, 8179–8205 (2017).
Ishii, M., Shouji, A., Sugimoto, S. & Matsumoto, T. Objective analyses of sea-surface temperature and marine meteorological variables for the 20th century using ICOADS and the Kobe collection. Int. J. Climatol. 25, 865–879 (2005).
Slivinski, L. C. et al. Towards a more reliable historical reanalysis: Improvements for version 3 of the Twentieth Century Reanalysis system. Q. J. R. Meteorol. Soc. 145, 2876–2908 (2019).
Poli, P. et al. ERA-20C: An atmospheric reanalysis of the twentieth century. J. Clim. 29, 4083–4097 (2016).
Kobayashi, S. et al. The JRA-55 reanalysis: General specifications and basic characteristics. J. Meteorol. Soc. Jpn. Ser. II 93, 5–48 (2015).
Lian, T., Chen, D., Ying, J., Huang, P. & Tang, Y. Tropical Pacific trends under global warming: El Niño-like or La Niña-like? Natl Sci. Rev. 5, 810–812 (2018).
Cai, W. et al. ENSO Response to Greenhouse Forcing, in El Niño Southern Oscillation in a Changing Climate (eds McPhaden, M. J., Santoso, A. & Cai, W.) (AGU, 2020).
Knutson, T. R. & Manabe, S. Time-mean response over the tropical Pacific to increased CO2 in a coupled ocean-atmosphere model. J. Clim. 8, 2181–2199 (1995).
Liu, Z., Vavrus, S., He, F., Wen, N. & Zhong, Y. Rethinking tropical ocean response to global warming: the enhanced equatorial warming. J. Clim. 18, 4684–4700 (2005).
Xie, S. et al. Global warming pattern formation: sea surface temperature and rainfall. J. Clim. 23, 966–986 (2010).
Meehl, G. & Washington, W. El Niño-like climate change in a model with increased atmospheric CO2 concentrations. Nature 382, 56–60 (1996).
Clement, A. C., Seager, R., Cane, M. A. & Zebiak, S. E. An ocean dynamical thermostat. J. Clim. 9, 2190–2196 (1996).
Watanabe, M. et al. Enhanced warming constrained by past trends in equatorial Pacific sea surface temperature gradient. Nat. Clim. Change 11, 33–37 (2021).
Kociuba, G. & Power, S. B. Inability of CMIP5 models to simulate recent strengthening of the Walker circulation: Implications for projections. J. Clim. 28, 20–35 (2015).
Coats, S. & Karnauskas, K. B. Are simulated and observed twentieth century tropical Pacific sea surface temperature trends significant relative to internal variability? Geophys. Res. Lett. 44, 9928–9937 (2017).
Zhang, L. et al. Indian Ocean warming trend reduces Pacific warming response to anthropogenic greenhouse gases: An interbasin thermostat mechanism. Geophys. Res. Lett. 46, 10882–10890 (2019).
McGregor, S. et al. Recent Walker circulation strengthening and Pacific cooling amplified by Atlantic warming. Nat. Clim. Change 4, 888–892 (2014).
Meehl, G. A. et al. Atlantic and Pacific tropics connected by mutually interactive decadal-timescale processes. Nat. Geosci. 14, 36–42 (2021).
Li, X., Xie, S.-P., Gille, S. T. & Yoo, C. Atlantic-induced pan-tropical climate change over the past three decades. Nat. Clim. Change 6, 275–279 (2016).
Lee, S.-K., Kim, D., Foltz, G. R. & Lopez, H. Pantropical response to global warming and the emergence of a La Niña-like mean state trend. Geophys. Res. Lett. 47, e2019GL086497 (2020).
McGregor, S. et al. Model tropical Atlantic biases underpin diminished Pacific decadal variability. Nat. Clim. Change 8, 493–498 (2018).
Kajtar, J. B., Santoso, A., McGregor, S., England, M. H. & Baillie, Z. Model under-representation of decadal Pacific trade wind trends and its link to tropical Atlantic bias. Clim. Dyn. 50, 1471–1484 (2018).
Li, C., Dommenget, D. & McGregor, S. Trans-basin Atlantic-Pacific connections further weakened by common model Pacific mean SST biases. Nat. Commun. 11, 5677 (2020).
Stuecker, M. F. et al. Strong remote control of future equatorial warming by off-equatorial forcing. Nat. Clim. Change 10, 124–129 (2020). Demonstrates opposite-signed feedbacks in the equatorial and off-equatorial regions to greenhouse gas forcing via coupled interactions between clouds, Hadley circulation and oceanic subtropical cells.
Heede, U. K., Fedorov, A. V. & Burls, N. J. Time scales and mechanisms for the tropical pacific response to global warming: a tug of war between the ocean thermostat and weaker Walker. J. Clim. 33, 6101–6118 (2020).
Cai, W. & Whetton, P. H. Evidence for a time-varying pattern of greenhouse warming in the Pacific Ocean. Geophys. Res. Lett. 27, 2577–2580 (2000).
Zheng, X.-T., Xie, S.-P., Lv, L. H. & Zhou, Z. Q. Intermodel uncertainty in ENSO amplitude change tied to Pacific Ocean warming pattern. J. Clim. 29, 7265–7279 (2016).
Kohyama, T., Hartmann, D. L. & Battisti, D. S. La Niña–like mean-state response to global warming and potential oceanic roles. J. Clim. 30, 4207–4225 (2017).
Hayashi, M., Jin, F.-F. & Stuecker, M. F. Dynamics for El Niño-La Niña asymmetry constrain equatorial-Pacific warming pattern. Nat. Commun. 11, 4230 (2020).
Ying, J., Huang, P., Lian, T. & Tan, H. Understanding the effect of an excessive cold tongue bias on projecting the tropical Pacific SST warming pattern in CMIP5 models. Clim. Dyn. 52, 1805–1818 (2018).
Taschetto, A. S. et al. Cold tongue and warm pool ENSO events in CMIP5: mean state and future projections. J. Clim. 27, 2861–2885 (2014).
DiNezio, P. N. et al. Mean climate controls on the simulated response of ENSO to increasing greenhouse gases. J. Clim. 25, 7399–7420 (2012).
Dommenget, D. & Vijayeta, A. Simulated future changes in ENSO dynamics in the framework of the linear recharge oscillator model. Clim. Dyn. 53, 4233–4248 (2019).
Chen, C., Cane, M. A., Wittenberg, A. T. & Chen, D. ENSO in the CMIP5 simulations: Life cycles, diversity, and responses to climate change. J. Clim. 30, 775–801 (2017).
Wang, G., Cai, W. & Santoso, A. Stronger increase in the frequency of extreme convective El Niño than extreme warm El Niño under greenhouse warming. J. Clim. 33, 675–690 (2020).
Zheng, X.-T., Hui, C., Xie, S.-P., Cai, W. & Long, S.-M. Intensification of El Niño rainfall variability over the tropical Pacific in the slow oceanic response to global warming. Geophys. Res. Lett. 46, 2253–2260 (2019).
Fredriksen, H.-B., Berner, J., Subramanian, A. C. & Capotondi, A. How does El Niño–Southern Oscillation change under global warming — A first look at CMIP6. Geophys. Res. Lett. 47, e2020GL090640 (2020).
Planton, Y. et al. Evaluating climate models with the CLIVAR 2020 ENSO metrics package. Bull. Am. Meteorol. Soc. 102, E193–E217 (2021).
McKenna, S., Santoso, A., Sen Gupta, A., Taschetto, A. & Cai, W. Indian Ocean Dipole in CMIP5 and CMIP6: characteristics, biases, and links to ENSO. Sci. Rep. 10, 11500 (2020).
Zhou, Z.-Q., Xie, S.-P., Zheng, X.-T., Liu, Q. & Wang, H. Global warming-induced changes in El Niño teleconnections over the North Pacific and North America. J. Clim. 27, 9050–9064 (2014).
Bonfils, C. J. et al. Relative contributions of mean-state shifts and ENSO-driven variability to precipitation changes in a warming climate. J. Clim. 28, 9997–10013 (2015).
Huang, P. & Chen, D. Enlarged asymmetry of tropical Pacific rainfall anomalies induced by El Niño and La Niña under global warming. J. Clim. 30, 1327–1343 (2017).
Chen, Z., Gan, B., Wu, L. & Jia, F. Pacific-North American teleconnection and North Pacific Oscillation: historical simulation and future projection in CMIP5 models. Clim. Dyn. 50, 4379–4403 (2018).
Yeh, S.-W. et al. Atmospheric teleconnections and their response to greenhouse gas forcing. Rev. Geophys. 56, 185–206 (2018).
Michel, C. et al. The change in the ENSO teleconnection under a low global warming scenario and the uncertainty due to internal variability. J. Clim. 33, 4871–4889 (2020).
Sohn, B.-J., Yeh, S.-W., Lee, A. & Lau, W. K. M. Regulation of atmospheric circulation controlling the tropical Pacific precipitation change in response to CO2 increases. Nat. Commun. 10, 1108 (2019).
Yan, Z. et al. Eastward shift and extension of ENSO-induced tropical precipitation anomalies under global warming. Sci. Adv. 6, eaax4177 (2020).
Beverley, J. D., Collins, M., Lambert, F. H. & Chadwick, R. Future changes to El Niño teleconnections over the North Pacific and North America. J. Clim. https://doi.org/10.1175/JCLI-D-20-0877.1 (2021).
Stevenson, S. L. Significant changes to ENSO strength and impacts in the twenty-first century: results from CMIP5. Geophy. Res. Lett. 39, L17703 (2012).
Tedeschi, R. G. & Collins, M. The influence of ENSO on South American precipitation: simulation and projection in CMIP5 models. Int. J. Climatol. 37, 3319–3339 (2017).
Power, S. B. & Delage, F. P. D. El Niño–Southern Oscillation and associated climatic conditions around the world during the latter half of the twenty-first century. J. Clim. 31, 6189–6207 (2018).
Perry, S. J., McGregor, S., Sen Gupta, A. & England, M. H. Future changes to El Niño–Southern Oscillation temperature and precipitation teleconnections. Geophys. Res. Lett. 44, 10608–10616 (2017).
Lyon, B. The strength of El Niño and the spatial extent of tropical drought. Geophys. Res. Lett. 3, L21204 (2004).
Delage, F. P. D. & Power, S. B. The impact of global warming and the El Niño-Southern Oscillation on seasonal precipitation extremes in Australia. Clim. Dyn. 54, 4367–4377 (2020).
Lin, I.-I. et al. ENSO and Tropical Cyclones, in El Niño Southern Oscillation in a Changing Climate (eds McPhaden, M. J., Santoso, A. & Cai, W.) (AGU, 2020).
Chand, S. et al. Projected increase in El Niño-driven tropical cyclone frequency in the Pacific. Nat. Clim. Change 7, 123–127 (2017). Shows that, during future climate ENSO, tropical cyclones become more frequent during El Niño and less frequent during La Niña over the off-equatorial western Pacific and central North Pacific islands.
Ying, J., Huang, P., Lian, T. & Chen, D. Intermodel uncertainty in the change of ENSO’s amplitude under global warming: role of the response of atmospheric circulation to SST anomalies. J. Clim. 32, 369–383 (2019).
Rodríguez-Fonseca, B. et al. Are Atlantic Niños enhancing Pacific ENSO events in recent decades? Geophys. Res. Lett. 36, L20705 (2009).
Ding, H., Keenlyside, N. S. & Latif, M. Impact of the equatorial Atlantic on the El Niño southern oscillation. Clim. Dyn. 38, 1965–1972 (2012).
Ham, Y.-G., Kug, J.-S., Park, J.-Y. & Jin, F.-F. Sea surface temperature in the north tropical Atlantic as a trigger for El Niño/Southern Oscillation events. Nat. Geosci. 6, 112–116 (2013).
Kug, J.-S. & Kang, I.-S. Interactive feedback between ENSO and the Indian Ocean. J. Clim. 19, 1784–1801 (2006).
Cai, W., Sullivan, A. & Cowan, T. Interactions of ENSO, the IOD, and the SAM in CMIP3 models. J. Clim. 24, 1688–1704 (2011).
Kucharski, F., Syed, F. S., Burhan, A., Farah, I. & Gohar, A. Tropical Atlantic influence on Pacific variability and mean state in the twentieth century in observations and CMIP5. Clim. Dyn. 44, 881–896 (2015).
Choi, J. Y., Ham, Y. G. & McGregor, S. Atlantic-Pacific SST gradient change responsible for the weakening of north tropical Atlantic-ENSO relationship due to global warming. Geophys. Res. Lett. 46, 7574–7582 (2019).
Jia, F., Wu, L., Gan, B. & Cai, W. Global warming attenuates the tropical Atlantic-Pacific teleconnection. Sci. Rep. 6, 20078 (2016).
Jia, F. et al. Weakening Atlantic Niño–Pacific connection under greenhouse warming. Sci. Adv. 5, eaax4111 (2019).
Kug, J.-S., Vialard, J., Ham, Y.-G., Yu, J.-Y. & Lengaigne, M. ENSO remote forcing, in El Niño Southern Oscillation in a Changing Climate (eds McPhaden, M. J., Santoso, A. & Cai, W.) (AGU, 2020)
Cheng, W., Chiang, J. C. H. & Zhang, D. Atlantic meridional overturning circulation (AMOC) in CMIP5 models: RCP and historical simulations. J. Clim. 26, 7187–7197 (2013).
Park, J. H. et al. Effect of recent Atlantic warming in strengthening Atlantic–Pacific teleconnection on interannual timescale via enhanced connection with the Pacific meridional mode. Clim. Dyn. 53, 371–387 (2019).
Wang, L., Yu, J.-Y. & Paek, H. Enhanced biennial variability in the Pacific due to Atlantic capacitor effect. Nat. Commun. 8, 14887 (2017).
Le, T. & Bae, D.-H. Causal links on interannual timescale between ENSO and the IOD in CMIP5 future simulations. Geophys. Res. Lett. 46, 2820–2828 (2019).
Sun, D.-Z. et al. Radiative and dynamical feedbacks over the equatorial cold tongue: results from nine atmospheric GCMs. J. Clim. 19, 4059–4074 (2006).
Lloyd, J., Guilyardi, E., Weller, H. & Slingo, J. The role of atmosphere feedbacks during ENSO in the CMIP3 models. Atmos. Sci. Lett. 10, 170–176 (2009).
Beobide-Arsuaga, G. et al. Uncertainty of ENSO-amplitude projections in CMIP5 and CMIP6 models. Clim. Dyn. 56, 3875–3888 (2021).
Guilyardi, E., Capotondi, A., Lengaigne, M., Thual, S. & Wittenberg, A. T. ENSO Modeling, in El Niño Southern Oscillation in a Changing Climate (eds McPhaden, M. J., Santoso, A. & Cai, W.) (AGU, 2020)
Bellenger, H., Guilyardi, E., Leloup, J., Lengaigne, M. & Vialard, J. ENSO representation in climate models: from CMIP3 to CMIP5. Clim. Dyn. 42, 1999–2018 (2014).
Kim, S.-T., Cai, W., Jin, F.-F. & Yu, J.-Y. ENSO stability in coupled climate models and its association with mean state. Clim. Dyn. 42, 3313–3321 (2014).
Bayr, T. et al. Error compensation of ENSO atmospheric feedbacks in climate models and its influence on simulated ENSO dynamics. Clim. Dyn. 53, 155–172 (2019).
Watanabe, T. et al. Permanent El Niño during the Pliocene warm period not supported by coral evidence. Nature 471, 209–211 (2011).
White, S. M. & Ravelo, A. C. Dampened El Niño in the early Pliocene warm period. Geophys. Res. Lett. 47, e2019GL085504 (2020).
Fedorov, A. et al. The Pliocene paradox (mechanisms for a permanent El Niño). Science 312, 1485–1489 (2006).
Steph, S. et al. Early Pliocene increase in thermohaline overturning: A precondition for the development of the modern equatorial Pacific cold tongue. Paleoceanography 25, PA2202 (2010).
Manucharyan, G. E. & Fedorov, A. V. Robust ENSO across a wide range of climates. J. Clim. 27, 5836–5850 (2014).
Ford, H. L., Ravelo, A. C. & Polissar, P. J. Reduced El Niño–Southern oscillation during the last glacial maximum. Science 347, 255–258 (2015).
Koutavas, A. & Joanides, S. El Niño–Southern oscillation extrema in the holocene and last glacial maximum. Paleoceanography 27, PA4208 (2012).
Rustic, G. T., Koutavas, A., Marchitto, T. M. & Linsley, B. K. Dynamical excitation of the tropical Pacific Ocean and ENSO variability by Little Ice Age cooling. Science 350, 1537–1541 (2015).
Sadekov, A. et al. Palaeoclimate reconstructions reveal a strong link between El Niño–Southern Oscillation and tropical Pacific mean state. Nat. Commun. 4, 2692 (2013).
Glaubke, R. H., Thirumalai, K., Schmidt, M. W. & Hertzberg, J. E. Discerning changes in high-frequency climate variability using geochemical populations of individual foraminifera. Paleoceanogr. Paleoclimatol. 36, e2020PA004065 (2021).
Wyman, D. A., Conroy, J. L. & Karamperidou, C. The tropical Pacific ENSO–mean state relationship in climate models over the last millennium. J. Clim. 33, 7539–7551 (2020).
Timmermann, A. & Jin, F. F. A nonlinear mechanism for decadal El Niño amplitude changes. Geophys. Res. Lett. 29, 1003 (2002).
Hayashi, M. & Jin, F. F. Subsurface nonlinear dynamical heating and ENSO asymmetry. Geophys. Res. Lett. 44, 12,427–12,435 (2017).
Conroy, J., Overpeck, J. T. & Cole, J. E. El Niño/Southern Oscillation and changes in the zonal gradient of tropical Pacific sea surface temperature over the last 1.2 ka. PAGES News 18, 32–34 (2010).
Rustic, G. T., Polissar, P. J., Ravelo, A. C. & White, S. M. Modulation of late Pleistocene ENSO strength by the tropical Pacific thermocline. Nat. Commun. 11, 5377 (2020).
Liu, Z. Y. et al. Evolution and forcing mechanisms of El Niño over the past 21,000 years. Nature 515, 550–553 (2014).
Karamperidou, C., Di Nezio, P. N., Timmermann, A., Jin, F.-F. & Cobb, K. M. The response of ENSO flavors to mid-Holocene climate: Implications for proxy interpretation. Paleoceanography 30, 527–547 (2015).
White, S. M., Ravelo, A. C. & Polissar, P. J. Dampened El Niño in the early and mid-Holocene due to insolation-forced warming/deepening of the thermocline. Geophys. Res. Lett. 16, 316–326 (2018).
Chen, L., Zheng, W. & Braconnot, P. Towards understanding the suppressed ENSO activity during mid-Holocene in PMIP2 and PMIP3 simulations. Clim. Dyn. 53, 1095–1110 (2019).
Brown, J. R. et al. Comparison of past and future simulations of ENSO in CMIP5/PMIP3 and CMIP6/PMIP4 models. Clim. Past. 16, 1777–1805 (2020).
Masson-Delmotte, V. et al. in Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (eds Stocker, T. F. et al) 383–464 (Cambridge Univ. Press, 2013).
Tudhope, A. W. et al. Variability in the El Niño-Southern Oscillation through a glacial-interglacial cycle. Science 291, 1511–1517 (2001).
Rodbell, D. T. et al. An ~15,000-year record of El Niño-driven alluviation in southwestern Ecuador. Science 283, 516–520 (1999).
Moy, C. M., Seltzer, G. O., Rodbell, D. T. & Anderson, D. M. Variability of El Niño/Southern Oscillation activity at millennial timescales during the Holocene epoch. Nature 420, 162–165 (2002).
Conroy, J. L., Overpeck, J. T., Cole, J. E., Shanahan, T. M. & Steinitz-Kannan, M. Holocene changes in eastern tropical Pacific climate inferred from a Galápagos lake sediment record. Quat. Sci. Rev. 27, 1166–1180 (2008).
Zhang, Z., Leduc, G. & Sachs, J. P. El Niño evolution during the Holocene revealed by a biomarker rain gauge in the Galápagos Islands. Earth Planet. Sci. Lett. 404, 420–434 (2014).
Chen, S. et al. A high-resolution speleothem record of western equatorial Pacific rainfall: Implications for Holocene ENSO evolution. Earth Planet. Sci. Lett. 442, 61–71 (2016).
Emile-Geay, J. Links between tropical Pacific seasonal, interannual and orbital variability during the Holocene. Nat. Geosci. 9, 168–173 (2016).
Carré, M. et al. Holocene history of ENSO variance and asymmetry in the eastern tropical Pacific. Science 345, 1045–1048 (2014).
McGregor, S. et al. The effect of strong volcanic eruptions on ENSO, in El Niño Southern Oscillation in a Changing Climate (eds McPhaden, M. J., Santoso, A. & Cai, W.) (AGU, 2020).
Adams, J. B., Mann, M. E. & Ammann, C. M. Proxy evidence for an El Nino-like response to volcanic forcing. Nature 426, 274–278 (2003).
Emile-Geay, J., Seager, R., Cane, M. A., Cook, E. R. & Haug, G. H. Volcanoes and ENSO over the past millennium. J. Clim. 21, 3134–3148 (2008).
Ohba, M., Shiogama, H., Yokohata, T. & Watanabe, M. Impact of strong tropical volcanic eruptions on ENSO simulated in a coupled GCM. J. Clim. 26, 5169–5182 (2013).
Stevenson, S., Otto-Bliesner, B., Fasullo, J. & Brady, E. “El Niño like” hydroclimate responses to last millennium volcanic eruptions. J. Clim. 29, 2907–2921 (2016).
Khodri, M. et al. Tropical explosive volcanic eruptions can trigger El Nino by cooling tropical Africa. Nat. Commun. 8, 778 (2017).
McGregor, S. & Timmermann, A. The effect of explosive tropical volcanism on ENSO. J. Clim. 24, 2178–2191 (2011).
Zanchettin, D. et al. Bidecadal variability excited in the coupled ocean–atmosphere system by strong tropical volcanic eruptions. Clim. Dyn. 39, 419–444 (2012).
Robock, A. Volcanic eruptions and climate. Rev. Geophys. 38, 191–219 (2000).
Ding, Y. et al. Ocean response to volcanic eruptions in Coupled Model Intercomparison Project 5 (CMIP5) simulations. J. Geophys. Res. Oceans 119, 5622–5637 (2014).
Dee, S. G. et al. No consistent ENSO response to volcanic forcing over the last millennium. Science 367, 1477–1481 (2020). Shows that proxy records reveal an insignificant tendency for an El Nino-like response in the year after a strong volcanic eruption, at odds with the strong tendencies found in climate models.
Pausata, F. S. R., Karamperidou, C., Caballero, R. & Battisti, D. S. ENSO response to high-latitude volcanic eruptions in the Northern Hemisphere: The role of the initial conditions. Geophys. Res. Lett. 43, 8694–8702 (2016).
Stevenson, S., Fasullo, J. T., Otto-Bliesner, B. L., Tomas, R. A. & Gao, C. Role of eruption season in reconciling model and proxy responses to tropical volcanism. Proc. Natl Acad. Sci. USA 114, 1822–1826 (2017).
Zanchettin, D. et al. Clarifying the relative role of forcing uncertainties and initial-condition unknowns in spreading the climate response to volcanic eruptions. Geophys. Res. Lett. 46, 1602–1611 (2019).
Pausata, F. S. R., Zanchettin, D., Karamperidou, C., Caballero, R. & Battisti, D. S. ITCZ shift and extratropical teleconnections drive ENSO response to volcanic eruptions. Sci. Adv. 6, eaaz5006 (2020).
Predybaylo, E. et al. El Niño/Southern Oscillation response to low-latitude volcanic eruptions depends on ocean pre-conditions and eruption timing. Commun. Earth Environ. 1, 12 (2020).
Emile-Geay, J. & Tingley, M. Inferring climate variability from nonlinear proxies: application to palaeo-ENSO studies. Clim. Past. 12, 31–50 (2016). Demonstrates the pitfalls of ignoring nonlinearities in the proxy–climate relationship, which often exaggerates climate variability changes inferred by proxies and leads to reconstructions with poorly quantified uncertainties.
Kiefer, J. & Karamperidou, C. High-resolution modeling of ENSO-induced precipitation in the tropical Andes: Implications for proxy interpretation. Paleoceanogr. Paleoclimatol. 34, 217–236 (2019).
Dee, S., Okumura, Y., Stevenson, S. & Di Nezio, P. Enhanced North American ENSO teleconnections during the Little Ice Age revealed by paleoclimate data assimilation. Geophys. Res. Lett. 47, e2020GL087504 (2020).
Chang, P. et al. Pacific meridional mode and El Niño — Southern Oscillation. Geophys. Res. Lett. 34, L16608 (2007).
Vimont, D. J., Alexander, M. & Fontaine, A. Midlatitude excitation of tropical variability in the Pacific: The role of thermodynamic coupling and seasonality. J. Clim. 22, 518–534 (2009).
Stuecker, M. F. Revisiting the Pacific meridional mode. Sci. Rep. 8, 3216 (2018).
Hong, L. C. & Jin, F. F. A southern hemisphere booster of super El Niño. Geophys. Res. Lett. 41, 2142–2149 (2014).
Holmes, R. M., McGregor, S., Santoso, A. & England, M. H. Contribution of tropical instability waves to ENSO irregularity. Clim. Dyn. 52, 1837–1855 (2019).
Bony, S. & Dufresne, J. L. Marine boundary layer clouds at the heart of tropical cloud feedback uncertainties in climate models. Geophys. Res. Lett. 32, L20806 (2005).
Deser, C. et al. Insights from Earth system model initial-condition large ensembles and future prospects. Nat. Clim. Change 10, 277–286 (2020).
Hawkins, E. & Sutton, R. Time of emergence of climate signals. Geophys. Res. Lett. 39, L01702 (2012).
Jochum, M. & Murtugudde, R. Temperature advection by tropical instability waves. J. Phys. Oceanogr. 36, 592–605 (2006).
An, S. I. Interannual variations of the tropical ocean instability wave and ENSO. J. Clim. 21, 3680–3686 (2008).
Bartlein, P. J. & Shafer, S. L. Paleo calendar-effect adjustments in time-slice and transient climate-model simulations (PaleoCalAdjust v1.0): impact and strategies for data analysis. Geosci. Model. Dev. 12, 3889–3913 (2019).
This work is supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, grant no. XDB40000000. W.C., A.S., B.N. and G.W. are supported by the Centre for Southern Hemisphere Oceans Research (CSHOR), a joint research facility between Qingdao National Laboratory for Marine Science and Technology (QNLM) and Commonwealth Scientific and Industrial Research Organisation (CSIRO), and the Earth System and Climate Change Hub of the Australian Government’s National Environment Science Program. M.F.S. was supported by the NOAA’s Climate Program Office’s Modeling, Analysis, Predictions, and Projections (MAPP) Program grant NA20OAR4310445 and participates in the MAPP Marine Ecosystem Task Force. This is Pacific Marine Environmental Laboratory (PMEL) contribution number 5213. M.L. is supported by the ARISE ANR (Agence Nationale pour la Recherche) project (ANR-18-CE01-0012). X. Lin is supported by the National Natural Science Foundation of China (41925025 and 92058203). B.G. was supported by the National Natural Science Foundation of China (41922039). A.C. is supported by the NOAA’s Climate Program Office Climate Variability and Predictability (CVP) and MAPP programs. M.C. was supported by NERC grant NE/S004645/1. This is IPRC publication 1525 and SOEST contribution 11356. A.S.T. is supported by the Australian Research Council (ARC FT160100495). S.-W.Y. is funded by the Korean Meteorological Administration Research and Development Program under grant (KMI2020-01213). Y.Y. is supported by the National Natural Science Foundation of China (NSFC) project (grant no. 41976005). X. Li is supported by National Key R&D Program of China (2018YFA0605703) and the National Natural Science Foundation of China (grant 41976193). M.C. is supported by NERC grant NE/S004645/1. T.B. is funded by Deutsche Forschungsgemeinschaft (DFG) project “Influence of Model Bias on ENSO Projections of the 21st Century” through grant 429334714. C.K. is supported by US NSF award AGS-1902970. J.R.B. acknowledges support from the ARC Centre of Excellence for Climate Extremes (CE170100023). J.Y. is supported by the National Natural Science Foundation of China (grants 41690121 and 41690120). A.T. was supported by the Institute for Basic Science (IBS-R028-D1). S.M. acknowledges support from the Australian Research Council through grant number Ft160100162. J.-S.K. is supported by the National Research Foundation of Korea (NRF-2018R1A5A1024958). X.-T.Z. is funded by the National Natural Science Foundation of China (41975092). B.D. acknowledges support from Fondecyt (grant 1190276) and ANR (grant ANR-18-CE01-0012). We acknowledge the World Climate Research Programme, which, through its Working Group on Coupled Modelling, coordinated and promoted CMIP6. We thank the climate modelling groups for producing and making available their model output, the Earth System Grid Federation (ESGF) for archiving the data and providing access, and the multiple funding agencies who support CMIP6 and ESGF. PMIP is endorsed by both WCRP/WGCM and Future Earth/PAGES.
The authors declare no competing interests.
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Cai, W., Santoso, A., Collins, M. et al. Changing El Niño–Southern Oscillation in a warming climate. Nat Rev Earth Environ 2, 628–644 (2021). https://doi.org/10.1038/s43017-021-00199-z
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