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- Kivimäki, Mika, et al.
(författare)
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Climate Change, Summer Temperature, and Heat-Related Mortality in Finland : Multicohort Study with Projections for a Sustainable vs. Fossil-Fueled Future to 2050
- 2023
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Ingår i: Journal of Environmental Health Perspectives. - : EHP Publishing. - 0091-6765 .- 1552-9924. ; 131:12, s. 1270201-1-1270201-16
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Climate change scenarios illustrate various pathways in terms of global warming ranging from "sustainable development" (Shared Socioeconomic Pathway SSP1-1.9), the best-case scenario, to 'fossil-fueled development' (SSP5-8.5), the worst-case scenario. OBJECTIVES: We examined the extent to which increase in daily average urban summer temperature is associated with future cause-specific mortality and projected heat-related mortality burden for the current warming trend and these two scenarios. METHODS: We did an observational cohort study of 363,754 participants living in six cities in Finland. Using residential addresses, participants were linked to daily temperature records and electronic death records from national registries during summers (1 May to 30 September) 2000 to 2018. For each day of observation, heat index (average daily air temperature weighted by humidity) for the preceding 7 d was calculated for participants' residential area using a geographic grid at a spatial resolution of formula presented . We examined associations of the summer heat index with risk of death by cause for all participants adjusting for a wide range of individual-level covariates and in subsidiary analyses using case-crossover design, computed the related period population attributable fraction (PAF), and projected change in PAF from summers 2000-2018 compared with those in 2030-2050. RESULTS: During a cohort total exposure period of 582,111,979 summer days (3,880,746 person-summers), we recorded 4,094 deaths, including 949 from cardiovascular disease. The multivariable-adjusted rate ratio (RR) for high (formula presented ) vs. reference (formula presented ) heat index was 1.70 (95% CI: 1.28, 2.27) for cardiovascular mortality, but it did not reach statistical significance for noncardiovascular deaths, formula presented (95% CI: 0.96, 1.36), a finding replicated in case-crossover analysis. According to projections for 2030-2050, PAF of summertime cardiovascular mortality attributable to high heat will be 4.4% (1.8%-7.3%) under the sustainable development scenario, but 7.6% (3.2%-12.3%) under the fossil-fueled development scenario. In the six cities, the estimated annual number of summertime heat-related cardiovascular deaths under the two scenarios will be 174 and 298 for a total population of 1,759,468 people. DISCUSSION: The increase in average urban summer temperature will raise heat-related cardiovascular mortality burden. The estimated magnitude of this burden is formula presented times greater if future climate change is driven by fossil fuels rather than sustainable development. https://doi.org/10.1289/EHP12080.
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| 2. |
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Reindeer husbandry under global change in the tundra region of Northern Fennoscandia
- 2017
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- The Nordic Centre of Excellence (NCoE) TUNDRA ("How to preserve the tundra in a changing climate") has been a 5-year project (2011–15) within the Top-Level Research Initiative (TRI) by NordForsk. This report combines the key results and a synthesis of the NCoE TUNDRA with earlier research to provide a comprehen- sive picture of the interplay between the tundra ecosystem, climate change and reindeer husbandry to relevant stakeholders. Most recent climate projections suggest that by the 2070s, temperature conditions that are warm enough for tree growth (> 10 °C average temperature during summer months) will cover almost all of northern Fennoscandia, excluding only the highest-altitude areas of the Scandinavian mountains. A warming climate will promote growth of shrubs and trees, a process that decreases the area of the tundra biome remarkably. The projected increase in spring temperatures will enhance snow melting. Together with the expansion and densification of shrub vegetation, this can significantly decrease surface reflectance (al- bedo), and have an amplifying feedback on global climate warming. Therefore, hindering shrub expansion and preserving the circumpolar high albedo tundra biome would serve as climate change mitigation. Herbivores (animals feeding on plants) have a strong impact on vegetation communities. The most important herbivores in Northern Fennoscandia include large mammals (reindeer), small mammals (rodents), and insects (geometrid moths). Their exact effect, however, varies between the animal groups and their population dynamics, seasons, weather conditions, and vegetation communities, and is dependent also on the combined impact of these animal groups. Reindeer grazing in particular has the potential to counter-impact the climate-induced shrubification. The maximum grazing impact on woody plants is obtained if reindeer are present in a region during early growing season in June and early July. In addition, grazing has an impact on plant biodiversity. By preventing the invasion of trees, tall shrubs and forbs, reindeer maintain the openness of the tundra, which is a precondition for the survival of many small-sized arctic plant species. Although grazing may disturb also these plant species, the net impact of intense summer grazing can be positive at the population level. From a transdisciplinary perspective, tundra is not only a biome, but also a social-ecological system (SES) incorporating humans and their activities, including reindeer husbandry. Decision-making involves various aspects of this complex social-ecological system and is, therefore, always a compromise and a matter of values and opinions. Reindeer husbandry exhibits major legal and administrative differences in local, regional, and state governance between Finland, Norway and Sweden. Anticipated changes in climate and within the societies require reindeer husbandry to adapt to these transformations. Future is notpre-determined but unveils itself as a chain of decisions and actions. Therefore, various scenarios of the future of the social-ecological system in Northern Fennoscandia – including reindeer husbandry – can be foresighted depending on the circumstances, decisions and actions. Current tensions between stakeholders – including reindeer herders, other land users, Sámi and non-Sámi individuals, and the governance system – stem from different values regarding ecological, cultural, social, and economic matters. These tensions may inhibit fruitful discussion and feasible decisions, and may lead to a future that is undesirable for many, if not all parties. At present, there is too little interaction, and inadequate, unequal discussion between the stakeholders. From the herders' perspective, unclear legislation and lack of self-determination are considered as threats for the livelihood. To improve the quality of decision making, planning and actions regarding future land use and livelihoods should be co-designed by different stakeholders. To overcome the historical apprehension between the parties, a neutral boundary organisation might serve as an appreciated mediator.
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| 3. |
- Virtanen, Risto, et al.
(författare)
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Where do the treeless tundra areas of northern highlands fit in the global biome system : toward an ecologically natural subdivision of the tundra biome
- 2016
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 6:1, s. 143-158
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Tidskriftsartikel (refereegranskat)abstract
- According to some treatises, arctic and alpine sub-biomes are ecologically similar, whereas others find them highly dissimilar. Most peculiarly, large areas of northern tundra highlands fall outside of the two recent subdivisions of the tundra biome. We seek an ecologically natural resolution to this long-standing and far-reaching problem. We studied broad-scale patterns in climate and vegetation along the gradient from Siberian tundra via northernmost Fennoscandia to the alpine habitats of European middle-latitude mountains, as well as explored those patterns within Fennoscandian tundra based on climate-vegetation patterns obtained from a fine-scale vegetation map. Our analyses reveal that ecologically meaningful January-February snow and thermal conditions differ between different types of tundra. High precipitation and mild winter temperatures prevail on middle-latitude mountains, low precipitation and usually cold winters prevail on high-latitude tundra, and Scandinavian mountains show intermediate conditions. Similarly, heath-like plant communities differ clearly between middle latitude mountains (alpine) and high-latitude tundra vegetation, including its altitudinal extension on Scandinavian mountains. Conversely, high abundance of snowbeds and large differences in the composition of dwarf shrub heaths distinguish the Scandinavian mountain tundra from its counterparts in Russia and the north Fennoscandian inland. The European tundra areas fall into three ecologically rather homogeneous categories: the arctic tundra, the oroarctic tundra of northern heights and mountains, and the genuinely alpine tundra of middlelatitude mountains. Attempts to divide the tundra into two sub-biomes have resulted in major discrepancies and confusions, as the oroarctic areas are included in the arctic tundra in some biogeographic maps and in the alpine tundra in others. Our analyses based on climate and vegetation criteria thus seem to resolve the long-standing biome delimitation problem, help in consistent characterization of research sites, and create a basis for further biogeographic and ecological research in global tundra environments.
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