The Paris Agreement binds all nations to undertake ambitious efforts to combat climate change, with the commitment to Bhold warming well below 2 °C in global mean temperature (GMT), relative to pre-industrial levels, and to pursue efforts to limit warming to 1.5 °C". The 1.5 °C limit constitutes an ambitious goal for which greater evidence on its benefits for health would help guide policy and potentially increase the motivation for action. Here we contribute to this gap with an assessment on the potential health benefits, in terms of reductions in temperature-related mortality, derived from the compliance to the agreed temperature targets, compared to more extreme warming scenarios. We performed a multi-region analysis in 451 locations in 23 countries with different climate zones, and evaluated changes in heat and cold-related mortality under scenarios consistent with the Paris Agreement targets (1.5 and 2 °C) and more extreme GMT increases (3 and 4 °C), and under the assumption of no changes in demographic distribution and vulnerability. Our results suggest that limiting warming below 2 °C could prevent large increases in temperature-related mortality in most regions worldwide. The comparison between 1.5 and 2 °C is more complex and characterized by higher uncertainty, with geographical differences that indicate potential benefits limited to areas located in warmer climates, where direct climate change impacts will be more discernible.

Center for Environmental and Respiratory Health Research University of Oulu Aapistie 5B FI 90014 Oulu Finland

Center for Health and the Global Environment University of Washington Seattle WA 98105 USA

Chemical and Environmental Effects Centre for Radiation Chemical and Environmental Hazards Public Health England Didcot Oxon Chilton London OX11 0RQ UK

Climate Analytics Ritterstraße 3 10969 Berlin Germany

Department of Environmental Engineering Graduate School of Engineering Kyoto University Kyoudai Katsura Campus Nishikyou Ward Kyoto 615 8540 Japan

Department of Environmental Health Harvard T H Chan School of Public Health 677 Huntington Ave Boston MA 02115 USA

Department of Environmental Health National Institute of Public Health Universidad No 655 Colonia Santa María Ahuacatitlán Cerrada Los Pinos y Caminera 62100 Cuernavaca Morelos Mexico

Department of Environmental Health School of Public Health Fudan University 138 Yi xue yuan Road Shanghai 200032 China

Department of Environmental Health University of São Paulo Av Dr Arnaldo 715 Cerqueira César São Paulo São Paulo 03178 200 Brazil

Department of Epidemiology and Preventive Medicine School of Public Health and Preventive Medicine Monash University 99 Commercial Road Melbourne VIC 3004 Australia

Department of Epidemiology Lazio Regional Health Service Via Cristoforo Colombo 112 00147 Rome Italy

Department of Global Ecology Graduate School of Global Environmental Studies Yoshidahonmachi Sakyo Ward Kyoto 606 8501 Japan

Department of Pediatric Infectious Diseases Institute of Tropical Medicine Nagasaki University 1 12 4 Sakamoto Nagasaki Nagasaki 852 8523 Japan

Department of Public Health and Clinical Medicine Umeå University 901 85 Umeå Sweden

Department of Public Health Environments and Society London School of Hygiene and Tropical Medicine Keppel St Bloomsbury London WC1E 7HT UK

Department of Public Health Universidad de los Andes Mons Alvaro del Portillo 12 455 Santiago Chile

Department of Statistics and Computational Research Environmental Health Joint Research Unit FISABIO UV UJI CIBERESP University of Valencia Valencia Spain

Division of Epidemiology and Biostatistics School of Population Health University of Queensland St Lucia Brisbane QLD 4072 Australia

Environmental and Occupational Medicine and Institute of Occupational Medicine and Industrial Hygiene National Taiwan University and NTU Hospital 1 Section 4 Roosevelt Rd Da'an District Taipei Taiwan

Faculty of Environmental Sciences Czech University of Life Sciences Kamycka 129 16521 Prague Czech Republic

Faculty of Health and Sport Sciences University of Tsukuba 1 1 1 Tennodai Tsukuba 305 8574 Japan

Faculty of Public Health University of Medicine and Pharmacy Ho Chi Minh city 217 Hồng Bàng Phường 11 Quận 5 Ho Chi Minh City Vietnam

Graduate School of Public Health Seoul National University 1Gwanak ro Gwanak gu Seoul 08826 Republic of Korea

Healthy Environments and Consumer Safety Branch Health Canada Ottawa Canada

Institute of Advanced Studies University of São Paulo Rua Praça do Relógio 109 Building K 5th floor Cidade Universitária ZC São Paulo São Paulo 05508 970 Brazil

Institute of Atmospheric Physics Academy of Sciences of the Czech Republic Bocni 1401 14131 Prague Czech Republic

Institute of Environment Health and Societies Brunel University London Kingston Ln Uxbridge London UB8 3PH UK

Institute of Environmental Assessment and Water Research Jordi Girona 18 26 08034 Barcelona Spain

Institute of Occupational Medicine Research Avenue North Riccarton Edinburgh EH14 4AP UK

Institute of Research and Development Duy Tan University 254 Nguyễn Văn Linh Thạc Gián Q Thanh Khê Da Nang Vietnam

National Institute of Environmental Health Sciences National Health Research Institutes 35 Keyan Road 35053 Zhunan Taiwan

Potsdam Institute for Climate Impact Research Telegrafenberg 14473 Potsdam Germany

Santé Publique France French National Public Health Agency 12 rue du Val d'Osne 94415 Saint Maurice France

School of Epidemiology and Public Health University of Ottawa 600 Peter Morand Crescent Ottawa K1G 5Z3 Canada

School of Forestry and Environmental Studies Yale University 195 Prospect St New Haven CT 06511 USA

School of Geographical Sciences University of Bristol University Road Bristol BS8 1SS UK

School of Physics Dublin Institute of Technology Kevin Street 2 Dublin D08 X622 Ireland

School of Public Health and Institute of Environment and Human Health Anhui Medical University Meishan Road Hefei 81 230032 China

School of Public Health and Social Work Queensland University of Technology 2 George St Brisbane City QLD 4000 Australia

Shanghai Children's Medical Centre Shanghai Jiao Tong University 1678 Dongfang Rd Shanghai 200127 China

Swiss Tropical and Public Health Institute Socinstrasse 57 4051 Basel Switzerland

Universidad Pablo de Olavide Carretera de Utrera 41013 Sevilla Spain

University of Basel Petersplatz 1 4001 Basel Switzerland

See more in PubMed

Benmarhnia T, Sottile M-F, Plante C, et al. Variability in temperature-related mortality projections under climate change. Environ Health Perspect. 2014;122:1293–1298. doi: 10.1289/ehp.1306954. PubMed DOI PMC

Ebi KL, Rocklöv J. Climate change and health modeling: horses for courses. Glob Health Action. 2014;7:24154. doi: 10.3402/gha.v7.24154. PubMed DOI PMC

Gasparrini A, Leone M. Attributable risk from distributed lag models. BMC Med Res Methodol. 2014;14:55. doi: 10.1186/1471-2288-14-55. PubMed DOI PMC

Gasparrini A, Guo Y, Hashizume M, et al. Mortality risk attributable to high and low ambient temperature: a multicountry observational study. Lancet Lond Engl. 2015;386:369–375. doi: 10.1016/S0140-6736(14)62114-0. PubMed DOI PMC

Gasparrini A, Guo Y, Sera F, et al. Projections of temperature-related excess mortality under climate change scenarios. Lancet Planet Health. 2017;1:e360–e367. doi: 10.1016/S2542-5196(17)30156-0. PubMed DOI PMC

Gosling SN, Hondula DM, Bunker A, et al. Adaptation to climate change: a comparative analysis of modeling methods for heat-related mortality. Environ Health Perspect. 2017;125:087008. doi: 10.1289/EHP634. PubMed DOI PMC

Harrington LJ, Frame DJ, Fischer EM, et al. Poorest countries experience earlier anthropogenic emergence of daily temperature extremes. Environ Res Lett. 2016;11:055007. doi: 10.1088/1748-9326/11/5/055007. DOI

IPCC Climate change 2014: synthesis report, contributions of working groups I, II and III to the fifth assessment report of the intergovernmental panel on climate change [Core Writing Team, Pachauri RK, Meyer LA, editors]. Geneva, Switzerland; 2014. XX p

James Rachel, Washington Richard, Schleussner Carl-Friedrich, Rogelj Joeri, Conway Declan. Characterizing half-a-degree difference: a review of methods for identifying regional climate responses to global warming targets. Wiley Interdisciplinary Reviews: Climate Change. 2017;8(2):e457.

Jones CD, Hughes JK, Bellouin N, et al. The HadGEM2-ES implementation of CMIP5 centennial simulations. Geosci Model Dev. 2011;4:543–570. doi: 10.5194/gmd-4-543-2011. DOI

Kottek Markus, Grieser Jürgen, Beck Christoph, Rudolf Bruno, Rubel Franz. World Map of the Köppen-Geiger climate classification updated. Meteorologische Zeitschrift. 2006;15(3):259–263. doi: 10.1127/0941-2948/2006/0130. DOI

Lelieveld J, Proestos Y, Hadjinicolaou P, et al. Strongly increasing heat extremes in the Middle East and North Africa (MENA) in the 21st century. Clim Chang. 2016;137:245–260. doi: 10.1007/s10584-016-1665-6. DOI

Mazdiyasni O, AghaKouchak A, Davis SJ, et al. Increasing probability of mortality during Indian heat waves. Sci Adv. 2017;3:e1700066. doi: 10.1126/sciadv.1700066. PubMed DOI PMC

Mignot J, Bony S. Presentation and analysis of the IPSL and CNRM climate models used in CMIP5. Clim Dyn. 2013;40:2089–2089. doi: 10.1007/s00382-013-1720-1. DOI

Mora Camilo, Dousset Bénédicte, Caldwell Iain R., Powell Farrah E., Geronimo Rollan C., Bielecki Coral R., Counsell Chelsie W. W., Dietrich Bonnie S., Johnston Emily T., Louis Leo V., Lucas Matthew P., McKenzie Marie M., Shea Alessandra G., Tseng Han, Giambelluca Thomas W., Leon Lisa R., Hawkins Ed, Trauernicht Clay. Global risk of deadly heat. Nature Climate Change. 2017;7(7):501–506. doi: 10.1038/nclimate3322. DOI

Russo S, Marchese AF, Sillmann J, Immé G. When will unusual heat waves become normal in a warming Africa? Environ Res Lett. 2016;11:054016. doi: 10.1088/1748-9326/11/5/054016. DOI

Sanderson Michael, Arbuthnott Katherine, Kovats Sari, Hajat Shakoor, Falloon Pete. The use of climate information to estimate future mortality from high ambient temperature: A systematic literature review. PLOS ONE. 2017;12(7):e0180369. doi: 10.1371/journal.pone.0180369. PubMed DOI PMC

Schleussner C-F, Lissner TK, Fischer EM, et al. Differential climate impacts for policy-relevant limits to global warming: the case of 1.5 °C and 2 °C. Earth Syst Dynam. 2016;7:327–351. doi: 10.5194/esd-7-327-2016. DOI

Seneviratne SI, Donat MG, Pitman AJ, et al. Allowable CO2 emissions based on regional and impact-related climate targets. Nature. 2016;529:477–483. doi: 10.1038/nature16542. PubMed DOI

Seneviratne SI, Rogelj J, Séférian R, et al. The many possible climates from the Paris Agreement’s aim of 1.5 °C warming. Nature. 2018;558:41–49. doi: 10.1038/s41586-018-0181-4. PubMed DOI

Smith KR, Woodward A, Campbell-Lendrum D, et al. Human health: impacts, adaptation, and co-benefits. In: Field CB, Barros VR, Dokken DJ, Mach KJ, Mastrandrea MD, Bilir TE, Chatterjee M, Ebi KL, Estrada YO, Genova RC, Girma B, Kissel ES, Levy AN, MacCracken S, Mastrandrea PR, White LL, et al., editors. Climate change 2014: impacts, adaptation, and vulnerability. Part A: global and sectoral aspects. Contribution of working group II to the fifth assessment report of the intergovernmental panel on climate change. Cambridge, United Kingdom and New York, NY, USA: Cambridge University Press; 2014. pp. 709–754.

UNFCCC (2015a) Report of the Conference of the Parties on its twenty-first session, held in Paris from 30 November to 11 December 2015. Addendum Part two: Action taken by the Conference of the Parties at its twenty-first session (https://unfccc.int/resource/docs/2015/cop21/eng/10.pdf). Accessed 15 May 2018

UNFCCC (2015b) Report of the structured expert dialogue on the 2013–2015 review. (https://unfccc.int/resource/docs/2015/sb/eng/inf01.pdf). Accessed 15 May 2018

Wang Y, Shi L, Zanobetti A, Schwartz JD. Estimating and projecting the effect of cold waves on mortality in 209 US cities. Environ Int. 2016;94:141–149. doi: 10.1016/j.envint.2016.05.008. PubMed DOI PMC

Watanabe S, Hajima T, Sudo K, et al. MIROC-ESM 2010: model description and basic results of CMIP5-20c3m experiments. Geosci Model Dev. 2011;4:845–872. doi: 10.5194/gmd-4-845-2011. DOI

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