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Elevated increases in human-perceived temperature under climate warming


Changes in air temperature (AT), humidity and wind speed (Wind) affect apparent temperature (AP), the human-perceived equivalent temperature1,2,3. Here we show that under climate warming, both reanalysis data sets and Global Climate Model simulations indicate that AP has increased faster than AT over land. The faster increase in AP has been especially significant over low latitudes and is expected to continue in the future. The global land average AP increased at 0.04 °C per decade faster than AT before 2005. This trend is projected to increase to 0.06 °C (0.03–0.09 °C; minimum and maximum of the ensemble members) per decade and 0.17 °C (0.12–0.25 °C) per decade under the Representative Concentration Pathway 4.5 scenario (RCP4.5) and RCP8.5, respectively, and reduce to 0.02 °C (0–0.03 °C) per decade under RCP2.6 over 2006–2100. The higher increment in AP in summer daytime is more remarkable than in winter night-time and is most prominent over low latitudes. The summertime increases in AT-based thermal discomfort are projected to balance the wintertime decreases in AT-based discomfort over low and middle latitudes, while the summertime increases in AP-based thermal discomfort are expected to outpace the wintertime decreases in AP-based thermal discomfort. Effective climate change mitigation efforts to achieve RCP2.6 can considerably alleviate the faster increase in AP.

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Fig. 1: Faster increases in AP than AT.
Fig. 2: Projections of summer and winter ∆(AP–AT) (°C) under future scenarios (2081–2100) relative to the historical scenario (1981–2000).
Fig. 3: Projected changes in the degree of thermal discomfort TDC (°C) and frequency of extremely hot days and extremely cold nights as a whole ∆f h+c (day) under future scenarios (2081–2100) relative to the historical scenario (1981–2000).
Fig. 4: Contributions of climatic factors to changes in daytime AP in 2081–2100 under RCP4.5 relative to 1981–2000.


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The authors acknowledge the World Climate Research Programme’s Working Group on Coupled Modelling, which is responsible for CMIP, and acknowledge the climate modelling groups for developing and making available their model output. For CMIP5, the US Department of Energy’s Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals. The work described in this Letter was supported by the Research Grants Council of the Hong Kong Special Administrative Region, China (project no. HKBU22301916) and a Direct Grant of The Chinese University of Hong Kong (project no. 4052134).

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J.L. and Y.D.C. designed the study. J.L. conducted the analysis. J.L., Y.D.C., T.Y.G. and N.-C.L. discussed the results and jointly wrote the paper.

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Correspondence to Yongqin David Chen.

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Supplementary Information

Supplementary Discussions 1–8, Supplementary Figures 1–45, Supplementary Methods, Supplementary Table 1, Supplementary References

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Li, J., Chen, Y.D., Gan, T.Y. et al. Elevated increases in human-perceived temperature under climate warming. Nature Clim Change 8, 43–47 (2018).

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