Abstract
Effective urban planning for climate-driven risks relies on robust climate projections specific to built landscapes. Such projections are absent because of a near-universal lack of urban representation in global-scale Earth system models. Here, we combine climate modelling and data-driven approaches to provide global multi-model projections of urban climates over the twenty-first century. The results demonstrate the inter-model robustness of specific levels of urban warming over certain regions under climate change. Under a high-emissions scenario, cities in the United States, Middle East, northern Central Asia, northeastern China and inland South America and Africa are estimated to experience substantial warming of more than 4 K—larger than regional warming—by the end of the century, with high inter-model confidence. Our findings highlight the critical need for multi-model global projections of local urban climates for climate-sensitive development and support green infrastructure intervention as an effective means of reducing urban heat stress on large scales.
This is a preview of subscription content, access via your institution
Relevant articles
Open Access articles citing this article.
-
Avoidable heat-related mortality in China during the 21st century
npj Climate and Atmospheric Science Open Access 08 July 2023
-
Rising vulnerability of compound risk inequality to ageing and extreme heatwave exposure in global cities
npj Urban Sustainability Open Access 24 June 2023
-
Surface warming in global cities is substantially more rapid than in rural background areas
Communications Earth & Environment Open Access 29 September 2022
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 print issues and online access
$209.00 per year
only $17.42 per issue
Rent or buy this article
Prices vary by article type
from$1.95
to$39.95
Prices may be subject to local taxes which are calculated during checkout





Data availability
All CMIP5 data used in this study are available at the CMIP5 archive via https://esgfnode.llnl.gov/projects/cmip5/ and the Climate Data Gateway at NCAR via https://www.earthsystemgrid.org/dataset/ucar.cgd.ccsm4.CESM_CAM5_BGC_LE.html for RCP 8.5 and https://www.earthsystemgrid.org/dataset/ucar.cgd.ccsm4.CESM_CAM5_BGC_ME.html for RCP 4.5. The output data from the emulator are available in the public repository—‘Illinois Data Bank’—via https://doi.org/10.13012/B2IDB-4585244_V1. Source data are provided with this paper.
Code availability
The R (https://www.R-project.org/) and NCL (The NCAR Command Language, https://doi.org/10.5065/D6WD3XH5) codes of the urban climate emulator are available on the NCAR Cheyenne cluster (https://doi.org/10.5065/D6RX99HX) and on Github (https://github.com/zhao-research-lab/urban_climate_emulator; https://doi.org/10.5281/zenodo.3893401). The CESM (used to perform the simulations) source code releases are available through the public GitHub repository (https://github.com/ESCOMP/CESM).
References
Grimm, N. B. et al. Global change and the ecology of cities. Science 319, 756–760 (2008).
Mora, C. et al. Global risk of deadly heat. Nat. Clim. Change 7, 501–506 (2017).
Schneider, A., Friedl, M. A. & Potere, D. A new map of global urban extent from MODIS satellite data. Environ. Res. Lett. 4, 044003 (2009).
Heilig, G. K. World Urbanization Prospects: The 2011 Revision (United Nations, 2012).
Cao, C. et al. Urban heat islands in China enhanced by haze pollution. Nat. Commun. 7, 12509 (2016).
Zhao, L. et al. Interactions between urban heat islands and heat waves. Environ. Res. Lett. 13, 034003 (2018).
Baklanov, A. et al. From urban meteorology, climate and environment research to integrated city services. Urban Clim. 23, 330–341 (2018).
Taylor, K. E., Stouffer, R. J. & Meehl, G. A. An overview of CMIP5 and the experiment design. Bull. Am. Meteorol. Soc. 93, 485–498 (2012).
Knutti, R. & Sedláček, J. Robustness and uncertainties in the new CMIP5 climate model projections. Nat. Clim. Change 3, 369–373 (2013).
Tebaldi, C. & Knutti, R. The use of the multi-model ensemble in probabilistic climate projections. Philos. Trans. R. Soc. A 365, 2053–2075 (2007).
Krayenhoff, E. S., Moustaoui, M., Broadbent, A. M., Gupta, V. & Georgescu, M. Diurnal interaction between urban expansion, climate change and adaptation in US cities. Nat. Clim. Change 8, 1097–1103 (2018).
Langendijk, G. S., Rechid, D. & Jacob, D. Urban areas and urban–rural contrasts under climate change: what does the EURO-CORDEX ensemble tell us?—Investigating near surface humidity in Berlin and its surroundings. Atmosphere 10, 730 (2019).
Daniel, M. et al. Benefits of explicit urban parameterization in regional climate modeling to study climate and city interactions. Clim. Dyn. 52, 2745–2764 (2019).
Li, D., Malyshev, S. & Shevliakova, E. Exploring historical and future urban climate in the Earth System Modeling framework: 1. Model development and evaluation. J. Adv. Model. Earth Syst. 8, 917–935 (2016).
McCarthy, M. P., Best, M. J. & Betts, R. A. Climate change in cities due to global warming and urban effects. Geophys. Res. Lett. 37, L09705 (2010).
Oleson, K. Contrasts between urban and rural climate in CCSM4 CMIP5 climate change scenarios. J. Clim. 25, 1390–1412 (2011).
Hawkins, E. & Sutton, R. The potential to narrow uncertainty in regional climate predictions. Bull. Am. Meteorol. Soc. 90, 1095–1108 (2009).
Oleson, K. W., Anderson, G. B., Jones, B., McGinnis, S. A. & Sanderson, B. Avoided climate impacts of urban and rural heat and cold waves over the U.S. using large climate model ensembles for RCP8.5 and RCP4.5. Climatic Change 146, 377–392 (2018).
Chapman, S., Watson, J. E. M., Salazar, A., Thatcher, M. & McAlpine, C. A. The impact of urbanization and climate change on urban temperatures: a systematic review. Landsc. Ecol. 32, 1921–1935 (2017).
Hoornweg, D. & Pope, K. Population predictions for the world’s largest cities in the 21st century. Environ. Urban. https://doi.org/10.1177/0956247816663557 (2016).
Hurrell, J. W. et al. The Community Earth System Model: a framework for collaborative research. Bull. Am. Meteorol. Soc. 94, 1339–1360 (2013).
Oleson, K., Bonan, G., Feddema, J., Vertenstein, M. & Kluzek, E. in Technical Description of an Urban Parameterization for the Community Land Model (CLMU) 169 (National Center for Atmospheric Research, 2010).
Zhao, L., Lee, X., Smith, R. B. & Oleson, K. Strong contributions of local background climate to urban heat islands. Nature 511, 216–219 (2014).
Demuzere, M. et al. Impact of urban canopy models and external parameters on the modelled urban energy balance in a tropical city. Q. J. R. Meteorol. Soc. 143, 1581–1596 (2017).
Karsisto, P. et al. Seasonal surface urban energy balance and wintertime stability simulated using three land-surface models in the high-latitude city Helsinki. Q. J. R. Meteorol. Soc. 142, 401–417 (2016).
Oleson, K. W., Bonan, G. B., Feddema, J., Vertenstein, M. & Grimmond, C. S. B. An urban parameterization for a global climate model. Part I: formulation and evaluation for two cities. J. Appl. Meteorol. Climatol. 47, 1038–1060 (2008).
Demuzere, M., Oleson, K., Coutts, A. M., Pigeon, G. & van Lipzig, N. P. M. Simulating the surface energy balance over two contrasting urban environments using the community land model urban. Int. J. Climatol. 33, 3182–3205 (2013).
Demuzere, M., De Ridder, K. & Van Lipzig, N. P. M. Modeling the energy balance in Marseille: sensitivity to roughness length parameterizations and thermal admittance. J. Geophys. Res. Atmos. 113, D16120 (2008).
Fitria, R., Kim, D., Baik, J. & Choi, M. Impact of biophysical mechanisms on urban heat island associated with climate variation and urban morphology. Sci. Rep. 9, 1–13 (2019).
Fischer, E. M., Oleson, K. W. & Lawrence, D. M. Contrasting urban and rural heat stress responses to climate change. Geophys. Res. Lett. 39, L03705 (2012).
Oleson, K. W., Bonan, G. B., Feddema, J. & Jackson, T. An examination of urban heat island characteristics in a global climate model. Int. J. Climatol. 31, 1848–1865 (2011).
Argüeso, D., Evans, J. P., Fita, L. & Bormann, K. J. Temperature response to future urbanization and climate change. Clim. Dyn. 42, 2183–2199 (2014).
Oke, T. R. The energetic basis of the urban heat island. Q. J. R. Meteorol. Soc. 108, 1–24 (1982).
Oleson, K. W., Bonan, G. B., Feddema, J. & Vertenstein, M. An urban parameterization for a global climate model. Part II: sensitivity to input parameters and the simulated urban heat island in offline simulations. J. Appl. Meteorol. Climatol. 47, 1061–1076 (2008).
Screen, J. A. & Simmonds, I. The central role of diminishing sea ice in recent Arctic temperature amplification. Nature 464, 1334–1337 (2010).
Markon, C. et al. in Fourth National Climate Assessment. Volume II. Impacts, Risks, and Adaptation in the United States, 1185–1241 (US Global Change Research Program, 2018); https://doi.org/10.7930/NCA4.2018.CH26
Li, J., Chen, Y. D., Gan, T. Y. & Lau, N.-C. Elevated increases in human-perceived temperature under climate warming. Nat. Clim. Change 8, 43–47 (2018).
Willett, K. M., Gillett, N. P., Jones, P. D. & Thorne, P. W. Attribution of observed surface humidity changes to human influence. Nature 449, 710–716 (2007).
Luo, M. & Lau, N.-C. Urban expansion and drying climate in an urban agglomeration of east China. Geophys. Res. Lett. 46, 6868–6877 (2019).
Lokoshchenko, M. A. Urban heat island and urban dry island in Moscow and their centennial changes. J. Appl. Meteorol. Climatol. 56, 2729–2745 (2017).
Moriwaki, R., Watanabe, K. & Morimoto, K. Urban dry island phenomenon and its impact on cloud base level. J. Jpn. Soc. Civil Eng. 1, 521–529 (2013).
Brutsaert, W. Evaporation into the Atmosphere: Theory, History and Applications (Springer, 1982).
Zhao, L., Lee, X. & Schultz, N. M. A wedge strategy for mitigation of urban warming in future climate scenarios. Atmos. Chem. Phys. 17, 9067–9080 (2017).
Grimmond, C. S. B. et al. The international urban energy balance models comparison project: first results from phase 1. J. Appl. Meteorol. Climatol. 49, 1268–1292 (2010).
Grimmond, C. S. B. et al. Initial results from Phase 2 of the international urban energy balance model comparison. Int. J. Climatol. 31, 244–272 (2011).
Matte, D., Larsen, M. A. D., Christensen, O. B. & Christensen, J. H. Robustness and scalability of regional climate projections over europe. Front. Environ. Sci. 6, 163 (2019).
Christensen, J. H., Larsen, M. A. D., Christensen, O. B., Drews, M. & Stendel, M. Robustness of european climate projections from dynamical downscaling. Clim. Dyn. 53, 4857–4869 (2019).
Gromke, C. et al. CFD analysis of transpirational cooling by vegetation: case study for specific meteorological conditions during a heat wave in Arnhem, Netherlands. Build. Environ. 83, 11–26 (2015).
Middel, A., Chhetri, N. & Quay, R. Urban forestry and cool roofs: assessment of heat mitigation strategies in Phoenix residential neighborhoods. Urban For. Urban Green. 14, 178–186 (2015).
Huang, H.-Y., Margulis, S. A., Chu, C. R. & Tsai, H.-C. Investigation of the impacts of vegetation distribution and evaporative cooling on synthetic urban daytime climate using a coupled LES—LSM model. Hydrol. Process. 25, 1574–1586 (2011).
Oleson, K. et al. in Technical Description of Version 4.0 of the Community Land Model (CLM) 257 (National Center for Atmospheric Research, 2010).
Jackson, T. L., Feddema, J. J., Oleson, K. W., Bonan, G. B. & Bauer, J. T. Parameterization of urban characteristics for global climate modeling. Ann. Assoc. Am. Geogr. 100, 848–865 (2010).
Zhang, J. C., Zhang, K., Liu, J. F. & Ban-Weiss, G. Revisiting the climate impacts of cool roofs around the globe using an Earth system model. Environ. Res. Lett. 11, 084014 (2016).
Hu, A. et al. Impact of solar panels on global climate. Nat. Clim. Change 6, 290–294 (2016).
Sanderson, B. M., Oleson, K. W., Strand, W. G., Lehner, F. & O'Neill, B. C. A new ensemble of GCM simulations to assess avoided impacts in a climate mitigation scenario. Climatic Change 146, 303–318 (2018).
Kay, J. E. et al. The Community Earth System Model (CESM) large ensemble project: a community resource for studying climate change in the presence of internal climate variability. Bull. Am. Meteorol. Soc. 96, 1333–1349 (2015).
Kusaka, H., Kondo, H., Kikegawa, Y. & Kimura, F. A simple single-layer urban canopy model for atmospheric models: comparison with multi-layer and slab models. Boundary Layer Meteorol. 101, 329–358 (2001).
Fowler, H. J., Blenkinsop, S. & Tebaldi, C. Linking climate change modelling to impacts studies: recent advances in downscaling techniques for hydrological modelling. Int. J. Climatol. 27, 1547–1578 (2007).
Vaittinada Ayar, P. et al. Intercomparison of statistical and dynamical downscaling models under the EURO- and MED-CORDEX initiative framework: present climate evaluations. Clim. Dyn. 46, 1301–1329 (2016).
Tang, J. et al. Statistical downscaling and dynamical downscaling of regional climate in China: present climate evaluations and future climate projections. J. Geophys. Res. Atmos. 121, 2110–2129 (2016).
Murphy, J. Predictions of climate change over Europe using statistical and dynamical downscaling techniques. Int. J. Climatol. 20, 489–501 (2000).
Spak, S., Holloway, T., Lynn, B. & Goldberg, R. A comparison of statistical and dynamical downscaling for surface temperature in North America. J. Geophys. Res. Atmos. 112, D08101 (2007).
Fowler, H. J. & Kilsby, C. G. Precipitation and the North Atlantic Oscillation: a study of climatic variability in northern England. Int. J. Climatol. 22, 843–866 (2002).
Wilby, R. L. Statistical downscaling of daily precipitation using daily airflow and seasonal teleconnection indices. Clim. Res. 10, 163–178 (1998).
Slonosky, V. C., Jones, P. D. & Davies, T. D. Atmospheric circulation and surface temperature in Europe from the 18th century to 1995. Int. J. Climatol. 21, 63–75 (2001).
Fischer, E. M. & Knutti, R. Robust projections of combined humidity and temperature extremes. Nat. Clim. Change 3, 126–130 (2013).
Epstein, Y. & Moran, D. S. Thermal comfort and the heat stress indices. Ind. Health 44, 388–398 (2006).
Buzan, J. R., Oleson, K. & Huber, M. Implementation and comparison of a suite of heat stress metrics within the Community Land Model version 4.5. Geosci. Model Dev. 8, 151–170 (2015).
Martilli, A., Krayenhoff, E. S. & Nazarian, N. Is the urban heat island intensity relevant for heat mitigation studies? Urban Clim. 31, 100541 (2020).
Stull, R. Wet-bulb temperature from relative humidity and air temperature. J. Appl. Meteorol. Climatol. 50, 2267–2269 (2011).
Acknowledgements
We thank the National Center for Atmospheric Research (NCAR) for supercomputing and data storage resources, including the Cheyenne supercomputer (https://doi.org/10.5065/D6RX99HX), which were provided by the Computational and Information Systems Laboratory (CISL) at NCAR. L.Z. and M.O. acknowledge the support from the High Meadows Foundation. K.O. acknowledges support by the US National Science Foundation (NSF) under grant no. AGS-1243095, and by NCAR, which is a major facility sponsored by the NSF under cooperative agreement no. 1852977. E.B.Z. acknowledges support by the Army Research Office under contract no. W911NF2010216 (program manager J. Barzyk), and the NSF under grant no. ICER 1664091 and SRN cooperative agreement no. 1444758. Q.Z. is supported by the Reducing Uncertainties in Biogeochemical Interactions through Synthesis and Computation (RUBISCO) Scientific Focus Area, Office of Biological and Environmental Research of the U.S. Department of Energy Office of Science.
Author information
Authors and Affiliations
Contributions
L.Z. conceptualized the research and designed the emulator modelling framework; L.Z. developed the reduced-order emulator with contributions from K.O., A.B. and C.C.; K.O. and L.Z. conducted the CESM simulations; L.Z. performed the data analysis; K.O., E.B.Z. and M.O. contributed ideas to the data analysis; L.Z., K.O. and E.S.K. performed the model validation; L.Z. drafted the manuscript, with discussions and contributions from K.O., E.B.Z., E.S.K., M.O. and other co-authors.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Peer review information Nature Climate Change thanks Joshua Hacker, Gaby Langendijk 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.
Extended data
Extended Data Fig. 1 Comparison of 2000–2009 JJA (June – August) distributions of diurnal average (Ta), minimum (Tmin) and maximum (Tmax) 2 m urban air temperature between CLMU (red), WRF (blue) and PRISM (green).
Center bar represent the median, box edges the 25th and 75th percentiles, and error bars the 1st and 99th percentiles. PHX = Phoenix; LAX = Los Angeles; CHI = Chicago; DNV = Denver; POR = Portland; BAL = Baltimore; MIA = Miami; DAL = Dallas; BOS = Boston; ATL = Atlanta.
Extended Data Fig. 2 Comparison of urban warming projection of diurnal average temperature between CESM and WRF-SLUCM simulation for season JJA (June – August) in 2090 – 2099 relative to 2000 – 2009 under RCP 8.5.
WRF-SLUCM dynamic downscaling simulation (forced by a CESM-RCP8.5 meteorology) was conducted in ref. 11. a, WRF-SLUCM projected urban warming in WRF’s original 20 km grids; b, CESM projected urban warming in the CESM grids (0.9° latitude × 1.25° longitude); c, WRF-SLUCM projected urban warming in the aggregated CESM grids (0.9° latitude × 1.25° longitude); d, difference in projected urban warming between CESM and WRF-SLUCM in the CESM grids.
Extended Data Fig. 3 Average root-mean-square-error (RMSE) in urban temperature and RH validation of the emulator across 5 CESM ensemble member runs (member #2 - #6).
The ‘error’ in RMSE denotes the difference between monthly temperatures or RH dynamically modeled by the CESM ensemble member and the ones modeled by the emulator. The average RMSE was calculated based on the 5 CESM ensemble member runs from 2006 to 2100 (that is 95 years). a-d: RCP 8.5; e-h: RCP 4.5. a and e: RMSE in diurnal average temperature Ta; b and f: RMSE in diurnal maximum temperature Tmax; c and g: RMSE in diurnal minimum temperature Tmin; d and h: RMSE in urban relative humidity RH.
Extended Data Fig. 4 Comparison of CMIP5 multi-model mean urban warming (ΔTurban) and background regional warming (ΔTbackground) for season JJA (June – August) in 2091 – 2100 relative to 2006 – 2015.
Δ refers to changes between end of the century and beginning of the century, that is (2091 to 2100) − (2006 to 2015); a, RCP 8.5; b, RCP 4.5.
Extended Data Fig. 5 Multi-model mean urban warming for season DJF (December – February) in 2091 – 2100 relative to 2006 – 2015.
a–c: RCP 8.5; d-f: RCP 4.5. a and d: urban warming in diurnal average temperature Ta; b and e: in diurnal maximum temperature Tmax; c and f: in diurnal minimum temperature Tmin. Stippling indicates substantial change (ΔT ≥ 4K under RCP 8.5 or ΔT ≥ 1.5K under RCP 4.5) with high inter-model robustness (SNR > 2.5).
Extended Data Fig. 6 Inter-model robustness of urban temperature projections measured by signal-to-noise ratio (SNR).
a–d, RCP 8.5; e-h, RCP 4.5. a, b, e and f: season JJA (June – August); c, d, g and h: season DJF (December – February); a, c, e and g: projection in diurnal maximum temperature Tmax; b, d, f and h: projection in diurnal minimum temperature Tmin.
Extended Data Fig. 7 Multi-model mean urban specific humidity (Q) change for season JJA (June – August) in 2091 – 2100 relative to 2006 – 2015.
a, RCP 8.5; b, RCP 4.5.
Extended Data Fig. 8 Multi-model mean urban relative humidity (RH) change for season DJF (December – February) in 2091 – 2100 relative to 2006 – 2015.
a, RCP 8.5; b, RCP 4.5.
Extended Data Fig. 9 Inter-model robustness of urban RH projections measured by signal-to-noise ratio (SNR).
a,b: RCP 8.5; c,d: RCP 4.5. a and c: season JJA (June – August); b and d: season DJF (December – February).
Extended Data Fig. 10 Multi-model mean of urban Δ(HI−Ta) for season JJA (June – August) in 2091 – 2100 relative to 2006 – 2015.
a: RCP 8.5; b: RCP 4.5. Stippling indicates substantial change (Δ(HI − Ta) > 3 K under RCP8.5 or Δ(HI − Ta) > 1.5 K under RCP4.5) with high inter-model robustness (SNR>2.5).
Supplementary information
Supplementary Information
Supplementary Table 1.
Source data
Source Data Fig. 1
Statistical source data.
Source Data Fig. 2
Statistical source data.
Source Data Fig. 3
Statistical source data.
Source Data Fig. 4
Statistical source data.
Source Data Fig. 5
Statistical source data.
Source Data Extended Data Fig. 1
Statistical source data.
Source Data Extended Data Fig. 2
Statistical source data.
Source Data Extended Data Fig. 3
Statistical source data.
Source Data Extended Data Fig. 4
Statistical source data.
Source Data Extended Data Fig. 5
Statistical source data.
Source Data Extended Data Fig. 6
Statistical source data.
Source Data Extended Data Fig. 7
Statistical source data.
Source Data Extended Data Fig. 8
Statistical source data.
Source Data Extended Data Fig. 9
Statistical source data.
Source Data Extended Data Fig. 10
Statistical source data.
Rights and permissions
About this article
Cite this article
Zhao, L., Oleson, K., Bou-Zeid, E. et al. Global multi-model projections of local urban climates. Nat. Clim. Chang. 11, 152–157 (2021). https://doi.org/10.1038/s41558-020-00958-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41558-020-00958-8
This article is cited by
-
Increased heat risk in wet climate induced by urban humid heat
Nature (2023)
-
Rising vulnerability of compound risk inequality to ageing and extreme heatwave exposure in global cities
npj Urban Sustainability (2023)
-
Avoidable heat-related mortality in China during the 21st century
npj Climate and Atmospheric Science (2023)
-
Future extreme high-temperature risk in the Beijing-Tianjin-Hebei urban agglomeration of China based on a regional climate model coupled with urban parameterization scheme
Theoretical and Applied Climatology (2023)
-
Climate change increases global risk to urban forests
Nature Climate Change (2022)