Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

You are viewing this page in draft mode.

Changing El Niño–Southern Oscillation in a warming climate

Abstract

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.

Key points

  • 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.

Your institute does not have access to this article

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Fig. 1: Key developments in understanding El Niño–Southern Oscillation response to greenhouse forcing.
Fig. 2: Observed El Niño–Southern Oscillation indices and their spatial representation.
Fig. 3: Observed and simulated tropical Pacific mean state and change.
Fig. 4: Projected increase in El Niño–Southern Oscillation sea surface temperature variability in CMIP6 models.
Fig. 5: Changing El Niño–Southern Oscillation teleconnections under greenhouse warming.
Fig. 6: Tropical Pacific mean state and El Niño–Southern Oscillation variability in past climates.
Fig. 7: Time of emergence of climate change signals.

References

  1. Philander et al. Unstable air-sea interactions in the tropics. J. Atmos. 41, 604–613 (1984).

    Article  Google Scholar 

  2. 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).

    Article  Google Scholar 

  3. McPhaden et al. ENSO as an integrating concept in earth science. Science 314, 1740–1745 (2006).

    Article  Google Scholar 

  4. L’Heureux, M. L. et al. Observing and predicting the 2015/16 El Niño. Bull. Am. Meteorol. Soc. 98, 1363–1382 (2017).

    Article  Google Scholar 

  5. 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).

    Article  Google Scholar 

  6. Bjerknes, J. Atmospheric teleconnections from the equatorial Pacific. Mon. Weather. Rev. 97, 163–172 (1969).

    Article  Google Scholar 

  7. Cai, W. et al. Climate impacts of the El Nino–Southern Oscillation on South America. Nat. Rev. Earth Environ. 1, 215–231 (2020).

    Article  Google Scholar 

  8. 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.

    Article  Google Scholar 

  9. 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).

    Article  Google Scholar 

  10. Holbrook, N. J. et al. Keeping pace with marine heatwaves. Nat. Rev. Earth Environ. 1, 482–493 (2020).

    Article  Google Scholar 

  11. Glynn, P. W. & de Weerdt, W. H. Elimination of two reef-building hydrocorals following the 1982–83 El Niño. Science 253, 69–71 (1991).

    Article  Google Scholar 

  12. Jonkman, S. N. Global perspectives on loss of human life caused by floods. Nat. Hazards 34, 151–175 (2005).

    Article  Google Scholar 

  13. 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).

    Article  Google Scholar 

  14. 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).

    Article  Google Scholar 

  15. McPhaden, M. J., Santoso, A., & Cai, W. (eds) El Niño Southern Oscillation in a Changing Climate Vol. 253 (Wiley, 2020).

  16. Collins, M. et al. The impact of global warming on the tropical Pacific Ocean and El Niño. Nat. Geosci. 3, 391–397 (2010).

    Article  Google Scholar 

  17. Cai, W. et al. ENSO and greenhouse warming. Nat. Clim. Change 5, 849–859 (2015).

    Article  Google Scholar 

  18. 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).

    Article  Google Scholar 

  19. 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).

    Article  Google Scholar 

  20. 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).

    Article  Google Scholar 

  21. 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).

  22. 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).

  23. Meehl, G. A., Brantstator, G. W. & Washington, W. M. Tropical Pacific interannual variability and CO2 climate change. J. Clim. 6, 42–63 (1993).

    Article  Google Scholar 

  24. 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).

    Article  Google Scholar 

  25. 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).

    Article  Google Scholar 

  26. Yun, K. S. et al. Increasing ENSO–rainfall variability due to changes in future tropical temperature–rainfall relationship. Commun. Earth Environ. 2, 43 (2021).

    Article  Google Scholar 

  27. Cai, W. et al. Increasing frequency of extreme El Niño events due to greenhouse warming. Nat. Clim. Change 4, 111–116 (2014).

    Article  Google Scholar 

  28. 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.

    Article  Google Scholar 

  29. Cai, W. et al. More extreme swings of the South Pacific convergence zone due to greenhouse warming. Nature 488, 365–369 (2012).

    Article  Google Scholar 

  30. 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).

    Article  Google Scholar 

  31. Santoso, A. et al. Late-twentieth-century emergence of the El Niño propagation asymmetry and future projections. Nature 504, 126–130 (2013).

    Article  Google Scholar 

  32. Cai, W. et al. Increased frequency of extreme La Niña events under greenhouse warming. Nat. Clim. Change 5, 132–137 (2015).

    Article  Google Scholar 

  33. 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.

    Article  Google Scholar 

  34. McGregor, S., Timmermann, A. & Timm, O. A unified proxy for ENSO and PDO variability since 1650. Clim. Past. 6, 1–17 (2010).

    Article  Google Scholar 

  35. 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).

    Article  Google Scholar 

  36. Cai, W. et al. Increased variability of eastern Pacific El Niño under greenhouse warming. Nature 564, 201–206 (2018).

    Article  Google Scholar 

  37. 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).

    Article  Google Scholar 

  38. Coats, S. & Karnauskas, K. B. A role for the equatorial undercurrent in the ocean dynamical thermostat. J. Clim. 31, 6245–6261 (2018).

    Article  Google Scholar 

  39. Seager, R. et al. Strengthening tropical Pacific zonal sea surface temperature gradient consistent with rising greenhouse gases. Nat. Clim. Change 9, 517–522 (2019).

    Article  Google Scholar 

  40. 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.

    Article  Google Scholar 

  41. Cai, W. et al. Pantropical climate interactions. Science 363, eaav4236 (2019).

    Article  Google Scholar 

  42. 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.

    Article  Google Scholar 

  43. 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).

    Google Scholar 

  44. 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).

    Article  Google Scholar 

  45. 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).

    Article  Google Scholar 

  46. 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.

    Google Scholar 

  47. 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).

    Article  Google Scholar 

  48. Capotondi, A. et al. Understanding ENSO diversity. Bull. Am. Meteorol. Soc. 96, 921–938 (2015).

    Article  Google Scholar 

  49. 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).

  50. Takahashi, K. & Dewitte, B. Strong and moderate nonlinear El Niño regimes. Clim. Dyn. 46, 1627–1645 (2016).

    Article  Google Scholar 

  51. Timmermann, A. et al. El Niño–southern oscillation complexity. Nature 559, 535–545 (2018).

    Article  Google Scholar 

  52. 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).

    Article  Google Scholar 

  53. Takahashi, K., Montecinos, A., Goubanova, K. & Dewitte, B. ENSO regimes: Reinterpreting the canonical and Modoki El Niño. Geophys. Res. Lett. 38, L10704 (2011).

    Article  Google Scholar 

  54. 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).

    Article  Google Scholar 

  55. Philip, S. Y. & van Oldenborgh, G. J. Shifts in ENSO coupling processes under global warming. Geophys. Res. Lett. 33, L11704 (2006).

    Article  Google Scholar 

  56. Jin, F.-F., Kim, S. T. & Bejarano, L. A coupled-stability index for ENSO. Geophys. Res. Lett. 33, L23708 (2006).

    Article  Google Scholar 

  57. 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).

    Article  Google Scholar 

  58. Carréric, A. et al. Change in strong Eastern Pacific El Niño events dynamics in the warming climate. Clim. Dyn. 54, 901–918 (2020).

    Article  Google Scholar 

  59. 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).

    Article  Google Scholar 

  60. Timmermann, A. et al. Increased El Niño frequency in a climate model forced by future greenhouse warming. Nature 398, 694–697 (1999).

    Article  Google Scholar 

  61. 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.

    Google Scholar 

  62. Zhang, Q., Guan, Y. & Yang, H. ENSO amplitude change in observation and coupled models. Adv. Atmos. Sci. 25, 361–366 (2008).

    Article  Google Scholar 

  63. Kim, S. T. et al. Response of El Niño sea surface temperature variability to greenhouse warming. Nat. Clim. Change 4, 786–790 (2014).

    Article  Google Scholar 

  64. Geng, T., Cai, W. & Wu, L. Two types of ENSO varying in tandem facilitated by nonlinear atmospheric convection. Geophys. Res. Lett. 47, e2020GL088784 (2020).

    Google Scholar 

  65. Capotondi, A. & Sardeshmukh, P. D. Is El Niño really changing? Geophys. Res. Lett. 44, 8548–8556 (2017).

    Article  Google Scholar 

  66. 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).

    Article  Google Scholar 

  67. Kennedy, J. J. A review of uncertainty in in situ measurements and data sets of sea surface temperature. Rev. Geophys. 52, 1–32 (2014).

    Article  Google Scholar 

  68. Li, J. et al. El Niño modulations over the past seven centuries. Nat. Clim. Change 3, 822–826 (2013).

    Article  Google Scholar 

  69. Liu, Y. et al. Recent enhancement of central Pacific El Niño variability relative to last eight centuries. Nat. Commun. 8, 15386 (2017).

    Article  Google Scholar 

  70. Cobb, K. M. et al. Highly variable El Niño–southern oscillation throughout the Holocene. Science 339, 67–70 (2013).

    Article  Google Scholar 

  71. 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).

  72. 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).

    Article  Google Scholar 

  73. 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).

    Article  Google Scholar 

  74. Huang, B. et al. Extended reconstructed sea surface temperature, version 5 (ERSSTv5): upgrades, validations, and intercomparisons. J. Clim. 30, 8179–8205 (2017).

    Article  Google Scholar 

  75. 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).

    Article  Google Scholar 

  76. 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).

    Article  Google Scholar 

  77. Poli, P. et al. ERA-20C: An atmospheric reanalysis of the twentieth century. J. Clim. 29, 4083–4097 (2016).

    Article  Google Scholar 

  78. Kobayashi, S. et al. The JRA-55 reanalysis: General specifications and basic characteristics. J. Meteorol. Soc. Jpn. Ser. II 93, 5–48 (2015).

    Article  Google Scholar 

  79. 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).

    Article  Google Scholar 

  80. 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).

  81. 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).

    Article  Google Scholar 

  82. 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).

    Article  Google Scholar 

  83. Xie, S. et al. Global warming pattern formation: sea surface temperature and rainfall. J. Clim. 23, 966–986 (2010).

    Article  Google Scholar 

  84. Meehl, G. & Washington, W. El Niño-like climate change in a model with increased atmospheric CO2 concentrations. Nature 382, 56–60 (1996).

    Article  Google Scholar 

  85. Clement, A. C., Seager, R., Cane, M. A. & Zebiak, S. E. An ocean dynamical thermostat. J. Clim. 9, 2190–2196 (1996).

    Article  Google Scholar 

  86. Watanabe, M. et al. Enhanced warming constrained by past trends in equatorial Pacific sea surface temperature gradient. Nat. Clim. Change 11, 33–37 (2021).

    Article  Google Scholar 

  87. 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).

    Article  Google Scholar 

  88. 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).

    Article  Google Scholar 

  89. 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).

    Article  Google Scholar 

  90. McGregor, S. et al. Recent Walker circulation strengthening and Pacific cooling amplified by Atlantic warming. Nat. Clim. Change 4, 888–892 (2014).

    Article  Google Scholar 

  91. Meehl, G. A. et al. Atlantic and Pacific tropics connected by mutually interactive decadal-timescale processes. Nat. Geosci. 14, 36–42 (2021).

    Article  Google Scholar 

  92. 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).

    Article  Google Scholar 

  93. 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).

    Google Scholar 

  94. McGregor, S. et al. Model tropical Atlantic biases underpin diminished Pacific decadal variability. Nat. Clim. Change 8, 493–498 (2018).

    Article  Google Scholar 

  95. 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).

    Article  Google Scholar 

  96. 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).

    Article  Google Scholar 

  97. 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.

    Article  Google Scholar 

  98. 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).

    Article  Google Scholar 

  99. 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).

    Article  Google Scholar 

  100. 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).

    Article  Google Scholar 

  101. 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).

    Article  Google Scholar 

  102. 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).

    Article  Google Scholar 

  103. 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).

    Article  Google Scholar 

  104. 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).

    Article  Google Scholar 

  105. DiNezio, P. N. et al. Mean climate controls on the simulated response of ENSO to increasing greenhouse gases. J. Clim. 25, 7399–7420 (2012).

    Article  Google Scholar 

  106. 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).

    Article  Google Scholar 

  107. 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).

    Article  Google Scholar 

  108. 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).

    Article  Google Scholar 

  109. 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).

    Article  Google Scholar 

  110. 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).

    Article  Google Scholar 

  111. Planton, Y. et al. Evaluating climate models with the CLIVAR 2020 ENSO metrics package. Bull. Am. Meteorol. Soc. 102, E193–E217 (2021).

    Article  Google Scholar 

  112. 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).

    Article  Google Scholar 

  113. 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).

    Article  Google Scholar 

  114. 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).

    Article  Google Scholar 

  115. 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).

    Article  Google Scholar 

  116. 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).

    Article  Google Scholar 

  117. Yeh, S.-W. et al. Atmospheric teleconnections and their response to greenhouse gas forcing. Rev. Geophys. 56, 185–206 (2018).

    Article  Google Scholar 

  118. 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).

    Article  Google Scholar 

  119. 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).

    Article  Google Scholar 

  120. Yan, Z. et al. Eastward shift and extension of ENSO-induced tropical precipitation anomalies under global warming. Sci. Adv. 6, eaax4177 (2020).

    Article  Google Scholar 

  121. 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).

    Article  Google Scholar 

  122. Stevenson, S. L. Significant changes to ENSO strength and impacts in the twenty-first century: results from CMIP5. Geophy. Res. Lett. 39, L17703 (2012).

    Article  Google Scholar 

  123. 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).

    Article  Google Scholar 

  124. 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).

    Article  Google Scholar 

  125. 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).

    Article  Google Scholar 

  126. Lyon, B. The strength of El Niño and the spatial extent of tropical drought. Geophys. Res. Lett. 3, L21204 (2004).

    Google Scholar 

  127. 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).

    Article  Google Scholar 

  128. 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).

  129. 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.

    Article  Google Scholar 

  130. 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).

    Article  Google Scholar 

  131. Rodríguez-Fonseca, B. et al. Are Atlantic Niños enhancing Pacific ENSO events in recent decades? Geophys. Res. Lett. 36, L20705 (2009).

    Article  Google Scholar 

  132. Ding, H., Keenlyside, N. S. & Latif, M. Impact of the equatorial Atlantic on the El Niño southern oscillation. Clim. Dyn. 38, 1965–1972 (2012).

    Article  Google Scholar 

  133. 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).

    Article  Google Scholar 

  134. Kug, J.-S. & Kang, I.-S. Interactive feedback between ENSO and the Indian Ocean. J. Clim. 19, 1784–1801 (2006).

    Article  Google Scholar 

  135. Cai, W., Sullivan, A. & Cowan, T. Interactions of ENSO, the IOD, and the SAM in CMIP3 models. J. Clim. 24, 1688–1704 (2011).

    Article  Google Scholar 

  136. 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).

    Article  Google Scholar 

  137. 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).

    Article  Google Scholar 

  138. Jia, F., Wu, L., Gan, B. & Cai, W. Global warming attenuates the tropical Atlantic-Pacific teleconnection. Sci. Rep. 6, 20078 (2016).

    Article  Google Scholar 

  139. Jia, F. et al. Weakening Atlantic Niño–Pacific connection under greenhouse warming. Sci. Adv. 5, eaax4111 (2019).

    Article  Google Scholar 

  140. 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)

  141. 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).

    Article  Google Scholar 

  142. 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).

    Article  Google Scholar 

  143. Wang, L., Yu, J.-Y. & Paek, H. Enhanced biennial variability in the Pacific due to Atlantic capacitor effect. Nat. Commun. 8, 14887 (2017).

    Article  Google Scholar 

  144. 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).

    Article  Google Scholar 

  145. 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).

    Article  Google Scholar 

  146. 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).

    Article  Google Scholar 

  147. Beobide-Arsuaga, G. et al. Uncertainty of ENSO-amplitude projections in CMIP5 and CMIP6 models. Clim. Dyn. 56, 3875–3888 (2021).

    Article  Google Scholar 

  148. 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)

  149. 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).

    Article  Google Scholar 

  150. 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).

    Article  Google Scholar 

  151. 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).

    Article  Google Scholar 

  152. Watanabe, T. et al. Permanent El Niño during the Pliocene warm period not supported by coral evidence. Nature 471, 209–211 (2011).

    Article  Google Scholar 

  153. White, S. M. & Ravelo, A. C. Dampened El Niño in the early Pliocene warm period. Geophys. Res. Lett. 47, e2019GL085504 (2020).

    Article  Google Scholar 

  154. Fedorov, A. et al. The Pliocene paradox (mechanisms for a permanent El Niño). Science 312, 1485–1489 (2006).

    Article  Google Scholar 

  155. 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).

    Article  Google Scholar 

  156. Manucharyan, G. E. & Fedorov, A. V. Robust ENSO across a wide range of climates. J. Clim. 27, 5836–5850 (2014).

    Article  Google Scholar 

  157. Ford, H. L., Ravelo, A. C. & Polissar, P. J. Reduced El Niño–Southern oscillation during the last glacial maximum. Science 347, 255–258 (2015).

    Article  Google Scholar 

  158. Koutavas, A. & Joanides, S. El Niño–Southern oscillation extrema in the holocene and last glacial maximum. Paleoceanography 27, PA4208 (2012).

    Article  Google Scholar 

  159. 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).

    Article  Google Scholar 

  160. 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).

    Article  Google Scholar 

  161. 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).

    Article  Google Scholar 

  162. 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).

    Article  Google Scholar 

  163. Timmermann, A. & Jin, F. F. A nonlinear mechanism for decadal El Niño amplitude changes. Geophys. Res. Lett. 29, 1003 (2002).

    Article  Google Scholar 

  164. Hayashi, M. & Jin, F. F. Subsurface nonlinear dynamical heating and ENSO asymmetry. Geophys. Res. Lett. 44, 12,427–12,435 (2017).

    Article  Google Scholar 

  165. 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).

    Article  Google Scholar 

  166. 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).

    Article  Google Scholar 

  167. Liu, Z. Y. et al. Evolution and forcing mechanisms of El Niño over the past 21,000 years. Nature 515, 550–553 (2014).

    Article  Google Scholar 

  168. 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).

    Article  Google Scholar 

  169. 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).

    Article  Google Scholar 

  170. 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).

    Article  Google Scholar 

  171. 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).

    Article  Google Scholar 

  172. 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).

  173. Tudhope, A. W. et al. Variability in the El Niño-Southern Oscillation through a glacial-interglacial cycle. Science 291, 1511–1517 (2001).

    Article  Google Scholar 

  174. Rodbell, D. T. et al. An ~15,000-year record of El Niño-driven alluviation in southwestern Ecuador. Science 283, 516–520 (1999).

    Article  Google Scholar 

  175. 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).

    Article  Google Scholar 

  176. 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).

    Article  Google Scholar 

  177. 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).

    Article  Google Scholar 

  178. 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).

    Article  Google Scholar 

  179. Emile-Geay, J. Links between tropical Pacific seasonal, interannual and orbital variability during the Holocene. Nat. Geosci. 9, 168–173 (2016).

    Article  Google Scholar 

  180. Carré, M. et al. Holocene history of ENSO variance and asymmetry in the eastern tropical Pacific. Science 345, 1045–1048 (2014).

    Article  Google Scholar 

  181. 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).

  182. 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).

    Article  Google Scholar 

  183. 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).

    Article  Google Scholar 

  184. 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).

    Article  Google Scholar 

  185. 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).

    Article  Google Scholar 

  186. Khodri, M. et al. Tropical explosive volcanic eruptions can trigger El Nino by cooling tropical Africa. Nat. Commun. 8, 778 (2017).

    Article  Google Scholar 

  187. McGregor, S. & Timmermann, A. The effect of explosive tropical volcanism on ENSO. J. Clim. 24, 2178–2191 (2011).

    Article  Google Scholar 

  188. Zanchettin, D. et al. Bidecadal variability excited in the coupled ocean–atmosphere system by strong tropical volcanic eruptions. Clim. Dyn. 39, 419–444 (2012).

    Article  Google Scholar 

  189. Robock, A. Volcanic eruptions and climate. Rev. Geophys. 38, 191–219 (2000).

    Article  Google Scholar 

  190. 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).

    Article  Google Scholar 

  191. 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.

    Article  Google Scholar 

  192. 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).

    Article  Google Scholar 

  193. 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).

    Article  Google Scholar 

  194. 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).

    Article  Google Scholar 

  195. 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).

    Article  Google Scholar 

  196. 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).

    Article  Google Scholar 

  197. 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.

    Article  Google Scholar 

  198. 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).

    Article  Google Scholar 

  199. 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).

    Article  Google Scholar 

  200. Chang, P. et al. Pacific meridional mode and El Niño — Southern Oscillation. Geophys. Res. Lett. 34, L16608 (2007).

    Article  Google Scholar 

  201. 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).

    Article  Google Scholar 

  202. Stuecker, M. F. Revisiting the Pacific meridional mode. Sci. Rep. 8, 3216 (2018).

    Article  Google Scholar 

  203. Hong, L. C. & Jin, F. F. A southern hemisphere booster of super El Niño. Geophys. Res. Lett. 41, 2142–2149 (2014).

    Article  Google Scholar 

  204. Holmes, R. M., McGregor, S., Santoso, A. & England, M. H. Contribution of tropical instability waves to ENSO irregularity. Clim. Dyn. 52, 1837–1855 (2019).

    Article  Google Scholar 

  205. 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).

    Article  Google Scholar 

  206. Deser, C. et al. Insights from Earth system model initial-condition large ensembles and future prospects. Nat. Clim. Change 10, 277–286 (2020).

    Article  Google Scholar 

  207. Hawkins, E. & Sutton, R. Time of emergence of climate signals. Geophys. Res. Lett. 39, L01702 (2012).

    Article  Google Scholar 

  208. Jochum, M. & Murtugudde, R. Temperature advection by tropical instability waves. J. Phys. Oceanogr. 36, 592–605 (2006).

    Article  Google Scholar 

  209. An, S. I. Interannual variations of the tropical ocean instability wave and ENSO. J. Clim. 21, 3680–3686 (2008).

    Article  Google Scholar 

  210. 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).

    Article  Google Scholar 

Download references

Acknowledgements

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.

Author information

Authors and Affiliations

Authors

Contributions

W.C. and A.S. conceived the study. W.C., M.J.M., M.F.S., M.L., A.S., J-S.K., A.S.T., S.-W.Y., C.K., B.D., M.C. and A.T. coordinated the presentation and discussion for various sections. F.J., B.N., G.W., Y.Y. and J.Y. contributed to analysis and the graphics of various figures. All authors contributed to the manuscript preparation, interpretation, discussion and writing, led by W.C.

Corresponding author

Correspondence to Wenju Cai.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information

Nature Reviews Earth & Environment thanks Nathaniel Johnson and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

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

Download citation

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s43017-021-00199-z

Further reading

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing