Projections of temperature-dependent mortality in Russian subarctic under climate change scenarios: a longitudinal study across several climate zones

Abstract

The magnitude of climate change in Arctic is greater than in other regions. Climate projections confirmed the ongoing warming in the circumpolar areas. The study goal was to estimate the fraction of mortality attributable to the exposition to non-optimal ambient temperatures during the 21st Century under the selected IPCC Representative Concentration Pathways RCP4.5 and RCP8.5. Three study areas were chosen to represent the different types of subarctic climate: from marine-type to transitional to extremely continental. Our dataset comprised 160363 deaths occurred between 1999 and 2016 in the cities of Murmansk, Archangelsk and Yakutsk. Non-linear distributed lag model was used to estimate the relationship between daily air temperatures and mortality rates. Daily temperature anomalies projected by the decades 2050-2059 and 2090-2099 were derived from the ensemble modelling with the regional climate model developed in the Voeikov Main Geophysical Observatory. The study showed positive net health impacts in all locations, and indicated uneven distribution of the benefits of climate change. Under the RCP8.5 scenario, mortality from all natural causes in the age group over 30 years will decrease by 4.5% (95% CI 1.1%; 7.9%) in Murmansk, 3.1% (1.1%; 5.1%) in Archangelsk and 3.6% (0.3%; 7.0%) in Yakutsk between the decades 1990-99 and 2090-99.