TY - JOUR A1 - Šedová, Barbora A1 - Kalkuhl, Matthias T1 - Who are the climate migrants and where do they go? BT - Evidence from rural India JF - World development N2 - In this paper, we move from the large strand of research that looks at evidence of climate migration to the questions: who are the climate migrants? and where do they go? These questions are crucial to design policies that mitigate welfare losses of migration choices due to climate change. We study the direct and heterogeneous associations between weather extremes and migration in rural India. We combine ERAS reanalysis data with the India Human Development Survey household panel and conduct regression analyses by applying linear probability and multinomial logit models. This enables us to establish a causal relationship between temperature and precipitation anomalies and overall migration as well as migration by destination. We show that adverse weather shocks decrease rural-rural and international migration and push people into cities in different, presumably more prosperous states. A series of positive weather shocks, however, facilitates international migration and migration to cities within the same state. Further, our results indicate that in contrast to other migrants, climate migrants are likely to be from the lower end of the skill distribution and from households strongly dependent on agricultural production. We estimate that approximately 8% of all rural-urban moves between 2005 and 2012 can be attributed to weather. This figure might increase as a consequence of climate change. Thus, a key policy recommendation is to take steps to facilitate integration of less educated migrants into the urban labor market. KW - climate change KW - migration KW - household analysis KW - India KW - econometrics Y1 - 2020 U6 - https://doi.org/10.1016/j.worlddev.2019.104848 SN - 0305-750X SN - 1873-5991 VL - 129 PB - Elsevier Science CY - Amsterdam ER - TY - JOUR A1 - Wolf, Sabina A1 - Pham, My A1 - Matthews, Nathanial A1 - Bubeck, Philip T1 - Understanding the implementation gap BT - policy-makers’ perceptions of ecosystem-based adaptation in Central Vietnam JF - Climate & development N2 - In recent years, nature-based solutions are receiving increasing attention in the field of disaster risk reduction and climate change adaptation as inclusive, no regret approaches. Ecosystem-based adaptation (EbA) can mitigate the impacts of climate change, build resilience and tackle environmental degradation thereby supporting the targets set by the 2030 Agenda, the Paris Agreement and the Sendai Framework. Despite these benefits, EbA is still rarely implemented in practice. To better understand the barriers to implementation, this research examines policy-makers' perceptions of EbA, using an extended version of Protection Motivation Theory as an analytical framework. Through semi-structured interviews with policy-makers at regional and provincial level in Central Vietnam, it was found that EbA is generally considered a promising response option, mainly due to its multiple ecosystem-service benefits. The demand for EbA measures was largely driven by the perceived consequences of natural hazards and climate change. Insufficient perceived response efficacy and time-lags in effectiveness for disaster risk reduction were identified as key impediments for implementation. Pilot projects and capacity building on EbA are important means to overcome these perceptual barriers. This paper contributes to bridging the knowledge-gap on political decision-making regarding EbA and can, thereby, promote its mainstreaming into policy plans. KW - climate change KW - ecosystem-based adaptation KW - risk perception KW - protection KW - motivation theory KW - decision making Y1 - 2020 U6 - https://doi.org/10.1080/17565529.2020.1724068 SN - 1756-5529 SN - 1756-5537 VL - 13 IS - 1 SP - 81 EP - 94 PB - Taylor & Francis LTD CY - Abingdon ER - TY - JOUR A1 - Kalkuhl, Matthias A1 - Wenz, Leonie T1 - The impact of climate conditions on economic production BT - evidence from a global panel of regions JF - Journal of Environmental Economics and Management N2 - We present a novel data set of subnational economic output, Gross Regional Product (GRP), for more than 1500 regions in 77 countries that allows us to empirically estimate historic climate impacts at different time scales. Employing annual panel models, long-difference regressions and cross-sectional regressions, we identify effects on productivity levels and productivity growth. We do not find evidence for permanent growth rate impacts but we find robust evidence that temperature affects productivity levels considerably. An increase in global mean surface temperature by about 3.5°C until the end of the century would reduce global output by 7–14% in 2100, with even higher damages in tropical and poor regions. Updating the DICE damage function with our estimates suggests that the social cost of carbon from temperature-induced productivity losses is on the order of 73–142$/tCO2 in 2020, rising to 92–181$/tCO2 in 2030. These numbers exclude non-market damages and damages from extreme weather events or sea-level rise. KW - climate change KW - climate damages KW - climate impacts KW - growth regression KW - global warming KW - panel regression KW - cross-sectional regression KW - damage KW - function KW - social costs of carbon Y1 - 2020 U6 - https://doi.org/10.1016/j.jeem.2020.102360 SN - 0095-0696 SN - 1096-0449 VL - 103 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Huber, Veronika A1 - Krummenauer, Linda A1 - Peña-Ortiz, Cristina A1 - Lange, Stefan A1 - Gasparrini, Antonio A1 - Vicedo-Cabrera, Ana Maria A1 - Garcia-Herrera, Ricardo A1 - Frieler, Katja T1 - Temperature-related excess mortality in German cities at 2 °C and higher degrees of global warming JF - Environmental Research N2 - Background: Investigating future changes in temperature-related mortality as a function of global mean temperature (GMT) rise allows for the evaluation of policy-relevant climate change targets. So far, only few studies have taken this approach, and, in particular, no such assessments exist for Germany, the most populated country of Europe. Methods: We assess temperature-related mortality in 12 major German cities based on daily time-series of all-cause mortality and daily mean temperatures in the period 1993-2015, using distributed-lag non-linear models in a two-stage design. Resulting risk functions are applied to estimate excess mortality in terms of GMT rise relative to pre-industrial levels, assuming no change in demographics or population vulnerability. Results: In the observational period, cold contributes stronger to temperature-related mortality than heat, with overall attributable fractions of 5.49% (95%CI: 3.82-7.19) and 0.81% (95%CI: 0.72-0.89), respectively. Future projections indicate that this pattern could be reversed under progressing global warming, with heat-related mortality starting to exceed cold-related mortality at 3 degrees C or higher GMT rise. Across cities, projected net increases in total temperature-related mortality were 0.45% (95%CI: -0.02-1.06) at 3 degrees C, 1.53% (95%CI: 0.96-2.06) at 4 degrees C, and 2.88% (95%CI: 1.60-4.10) at 5 degrees C, compared to today's warming level of 1 degrees C. By contrast, no significant difference was found between projected total temperature-related mortality at 2 degrees C versus 1 degrees C of GMT rise. Conclusions: Our results can inform current adaptation policies aimed at buffering the health risks from increased heat exposure under climate change. They also allow for the evaluation of global mitigation efforts in terms of local health benefits in some of Germany's most populated cities. KW - temperature-related mortality KW - climate change KW - Future projections KW - Germany KW - global mean temperature Y1 - 2020 U6 - https://doi.org/10.1016/j.envres.2020.109447 SN - 0013-9351 SN - 1096-0953 VL - 186 SP - 1 EP - 10 PB - Elsevier CY - San Diego, California ER - TY - JOUR A1 - Tesselaar, Max A1 - Botzen, W. J. Wouter A1 - Haer, Toon A1 - Hudson, Paul A1 - Tiggeloven, Timothy A1 - Aerts, Jeroen C. J. H. T1 - Regional inequalities in flood insurance affordability and uptake under climate change JF - Sustainability N2 - Flood insurance coverage can enhance financial resilience of households to changing flood risk caused by climate change. However, income inequalities imply that not all households can afford flood insurance. The uptake of flood insurance in voluntary markets may decline when flood risk increases as a result of climate change. This increase in flood risk may cause substantially higher risk-based insurance premiums, reduce the willingness to purchase flood insurance, and worsen problems with the unaffordability of coverage for low-income households. A socio-economic tipping-point can occur when the functioning of a formal flood insurance system is hampered by diminishing demand for coverage. In this study, we examine whether such a tipping-point can occur in Europe for current flood insurance systems under different trends in future flood risk caused by climate and socio-economic change. This analysis gives insights into regional inequalities concerning the ability to continue to use flood insurance as an instrument to adapt to changing flood risk. For this study, we adapt the "Dynamic Integrated Flood and Insurance" (DIFI) model by integrating new flood risk simulations in the model that enable examining impacts from various scenarios of climate and socio-economic change on flood insurance premiums and consumer demand. Our results show rising unaffordability and declining demand for flood insurance across scenarios towards 2080. Under a high climate change scenario, simulations show the occurrence of a socio-economic tipping-point in several regions, where insurance uptake almost disappears. A tipping-point and related inequalities in the ability to use flood insurance as an adaptation instrument can be mitigated by introducing reforms of flood insurance arrangements. KW - climate change KW - flood risk management KW - insurance KW - socio-economic KW - tipping-point KW - adaptation KW - partial equilibrium modeling Y1 - 2020 U6 - https://doi.org/10.3390/su12208734 SN - 2071-1050 VL - 12 IS - 20 PB - MDPI CY - Basel ER - TY - JOUR A1 - Pan, Xiaohui A1 - Wang, Weishi A1 - Liu, Tie A1 - Huang, Yue A1 - De Maeyer, Philippe A1 - Guo, Chenyu A1 - Ling, Yunan A1 - Akmalov, Shamshodbek T1 - Quantitative detection and attribution of groundwater level variations in the Amu Darya Delta JF - Water N2 - In the past few decades, the shrinkage of the Aral Sea is one of the biggest ecological catastrophes caused by human activity. To quantify the joint impact of both human activities and climate change on groundwater, the spatiotemporal groundwater dynamic characteristics in the Amu Darya Delta of the Aral Sea from 1999 to 2017 were analyzed, using the groundwater level, climate conditions, remote sensing data, and irrigation information. Statistics analysis was adopted to analyze the trend of groundwater variation, including intensity, periodicity, spatial structure, while the Pearson correlation analysis and principal component analysis (PCA) were used to quantify the impact of climate change and human activities on the variabilities of the groundwater level. Results reveal that the local groundwater dynamic has varied considerably. From 1999 to 2002, the groundwater level dropped from -189 cm to -350 cm. Until 2017, the groundwater level rose back to -211 cm with fluctuation. Seasonally, the fluctuation period of groundwater level and irrigation water was similar, both were about 18 months. Spatially, the groundwater level kept stable within the irrigation area and bare land but fluctuated drastically around the irrigation area. The Pearson correlation analysis reveals that the dynamic of the groundwater level is closely related to irrigation activity within the irrigation area (Nukus: -0.583), while for the place adjacent to the Aral Sea, the groundwater level is closely related to the Large Aral Sea water level (Muynak: 0.355). The results of PCA showed that the cumulative contribution rate of the first three components exceeds 85%. The study reveals that human activities have a great impact on groundwater, effective management, and the development of water resources in arid areas is an essential prerequisite for ecological protection. KW - groundwater level variation KW - climate change KW - human activities KW - statistical analysis KW - Amu Darya Delta Y1 - 2020 U6 - https://doi.org/10.3390/w12102869 SN - 2073-4441 VL - 12 IS - 10 PB - MDPI CY - Basel ER - TY - JOUR A1 - Mogrovejo Arias, Diana Carolina A1 - Brill, Florian H. H. A1 - Wagner, Dirk T1 - Potentially pathogenic bacteria isolated from diverse habitats in Spitsbergen, Svalbard JF - Environmental earth sciences N2 - The Arctic ecosystem, a reservoir of genetic microbial diversity, represents a virtually unlimited source of microorganisms that could interact with human beings. Despite continuous exploration of Arctic habitats and description of their microbial communities, bacterial phenotypes commonly associated with pathogenicity, such as hemolytic activity, have rarely been reported. In this study, samples of snow, fresh and marine water, soil, and sediment from several habitats in the Arctic archipelago of Svalbard were collected during Summer, 2017. Bacterial isolates were obtained after incubation on oligotrophic media at different temperatures and their hemolytic potential was assessed on sheep blood agar plates. Partial (alpha) or true (beta) hemolysis was observed in 32 out of 78 bacterial species. Genes expressing cytolytic compounds, such as hemolysins, likely increase the general fitness of the producing microorganisms and confer a competitive advantage over the availability of nutrients in natural habitats. In environmental species, the nutrient-acquisition function of these compounds presumably precedes their function as toxins for mammalian erythrocytes. However, in the light of global warming, the presence of hemolytic bacteria in Arctic environments highlights the possible risks associated with these microorganisms in the event of habitat melting/destruction, ecosystem transition, and re-colonization. KW - Arctic KW - Svalbard KW - hemolysins KW - climate change KW - pathogens KW - virulence Y1 - 2020 U6 - https://doi.org/10.1007/s12665-020-8853-4 SN - 1866-6280 SN - 1866-6299 VL - 79 IS - 5 PB - Springer CY - Berlin ; Heidelberg ER - TY - JOUR A1 - Marzetz, Vanessa A1 - Spijkerman, Elly A1 - Striebel, Maren A1 - Wacker, Alexander T1 - Phytoplankton community responses to interactions between light intensity, light variations, and phosphorus supply JF - Frontiers in Environmental Science N2 - In a changing world, phytoplankton communities face a large variety of challenges including altered light regimes. These alterations are caused by more pronounced stratification due to rising temperatures, enhanced eutrophication, and browning of lakes. Community responses toward these effects can emerge as alterations in physiology, biomass, biochemical composition, or diversity. In this study, we addressed the combined effects of changes in light and nutrient conditions on community responses. In particular, we investigated how light intensity and variability under two nutrient conditions influence (1) fast responses such as adjustments in photosynthesis, (2) intermediate responses such as pigment adaptation and (3) slow responses such as changes in community biomass and species composition. Therefore, we exposed communities consisting of five phytoplankton species belonging to different taxonomic groups to two constant and two variable light intensity treatments combined with two levels of phosphorus supply. The tested phytoplankton communities exhibited increased fast reactions of photosynthetic processes to light variability and light intensity. The adjustment of their light harvesting mechanisms via community pigment composition was not affected by light intensity, variability, or nutrient supply. However, pigment specific effects of light intensity, light variability, and nutrient supply on the proportion of the respective pigments were detected. Biomass was positively affected by higher light intensity and nutrient concentrations while the direction of the effect of variability was modulated by light intensity. Light variability had a negative impact on biomass at low, but a positive impact at high light intensity. The effects on community composition were species specific. Generally, the proportion of green algae was higher under high light intensity, whereas the cyanobacterium performed better under low light conditions. In addition to that, the diatom and the cryptophyte performed better with high nutrient supply while the green algae as well as the cyanobacterium performed better at low nutrient conditions. This shows that light intensity, light variability, and nutrient supply interactively affect communities. Furthermore, the responses are highly species and pigment specific, thus to clarify the effects of climate change a deeper understanding of the effects of light variability and species interactions within communities is important. KW - phytoplankton communities KW - light variability KW - photosynthetic rate KW - climate change KW - resource competition KW - light intensity (irradiance) KW - pigment composition KW - nutrient supply Y1 - 2020 U6 - https://doi.org/10.3389/fenvs.2020.539733 SN - 2296-665X VL - 8 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Marzetz, Vanessa A1 - Spijkerman, Elly A1 - Striebel, Maren A1 - Wacker, Alexander T1 - Phytoplankton Community Responses to Interactions Between Light Intensity, Light Variations, and Phosphorus Supply JF - Frontiers in Environmental Science N2 - In a changing world, phytoplankton communities face a large variety of challenges including altered light regimes. These alterations are caused by more pronounced stratification due to rising temperatures, enhanced eutrophication, and browning of lakes. Community responses toward these effects can emerge as alterations in physiology, biomass, biochemical composition, or diversity. In this study, we addressed the combined effects of changes in light and nutrient conditions on community responses. In particular, we investigated how light intensity and variability under two nutrient conditions influence (1) fast responses such as adjustments in photosynthesis, (2) intermediate responses such as pigment adaptation and (3) slow responses such as changes in community biomass and species composition. Therefore, we exposed communities consisting of five phytoplankton species belonging to different taxonomic groups to two constant and two variable light intensity treatments combined with two levels of phosphorus supply. The tested phytoplankton communities exhibited increased fast reactions of photosynthetic processes to light variability and light intensity. The adjustment of their light harvesting mechanisms via community pigment composition was not affected by light intensity, variability, or nutrient supply. However, pigment specific effects of light intensity, light variability, and nutrient supply on the proportion of the respective pigments were detected. Biomass was positively affected by higher light intensity and nutrient concentrations while the direction of the effect of variability was modulated by light intensity. Light variability had a negative impact on biomass at low, but a positive impact at high light intensity. The effects on community composition were species specific. Generally, the proportion of green algae was higher under high light intensity, whereas the cyanobacterium performed better under low light conditions. In addition to that, the diatom and the cryptophyte performed better with high nutrient supply while the green algae as well as the cyanobacterium performed better at low nutrient conditions. This shows that light intensity, light variability, and nutrient supply interactively affect communities. Furthermore, the responses are highly species and pigment specific, thus to clarify the effects of climate change a deeper understanding of the effects of light variability and species interactions within communities is important. KW - phytoplankton communities KW - light variability KW - photosynthetic rate KW - climate change KW - resource competition KW - light intensity (irradiance) KW - pigment composition KW - nutrient supply Y1 - 2020 U6 - https://doi.org/10.3389/fenvs.2020.539733 SN - 2296-665X VL - 8 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Stoof-Leichsenring, Kathleen Rosemarie A1 - Pestryakova, Luidmila Agafyevna A1 - Epp, Laura Saskia A1 - Herzschuh, Ulrike T1 - Phylogenetic diversity and environment form assembly rules for Arctic diatom genera BT - a study on recent and ancient sedimentary DNA JF - Journal of Biogeography N2 - Aim This study investigates taxonomic and phylogenetic diversity in diatom genera to evaluate assembly rules for eukaryotic microbes across the Siberian tree line. We first analysed how phylogenetic distance relates to taxonomic richness and turnover. Second, we used relatedness indices to evaluate if environmental filtering or competition influences the assemblies in space and through time. Third, we used distance-based ordination to test which environmental variables shape diatom turnover. Location Yakutia and Taymyria, Russia: we sampled 78 surface sediments and a sediment core, extending to 7,000 years before present, to capture the forest-tundra transition in space and time respectively. Taxon Arctic freshwater diatoms. Methods We applied metabarcoding to retrieve diatom diversity from surface and core sedimentary DNA. The taxonomic assignment binned sequence types (lineages) into genera and created taxonomic (abundance of lineages within different genera) and phylogenetic datasets (phylogenetic distances of lineages within different genera). Results Contrary to our expectations, we find a unimodal relationship between phylogenetic distance and richness in diatom genera. We discern a positive relationship between phylogenetic distance and taxonomic turnover in spatially and temporally distributed diatom genera. Furthermore, we reveal positive relatedness indices in diatom genera across the spatial environmental gradient and predominantly in time slices at a single location, with very few exceptions assuming effects of competition. Distance-based ordination of taxonomic and phylogenetic turnover indicates that lake environment variables, like HCO3- and water depth, largely explain diatom turnover. Main conclusion Phylogenetic and abiotic assembly rules are important in understanding the regional assembly of diatom genera across lakes in the Siberian tree line ecotone. Using a space-time approach we are able to exclude the influence of geography and elucidate that lake environmental variables primarily shape the assemblies. We conclude that some diatom genera have greater capabilities to adapt to environmental changes, whereas others will be putatively replaced or lost due to the displacement of the Arctic tundra biome under recent global warming. KW - ancient sedimentary DNA KW - Arctic lakes KW - assembly rules KW - climate change KW - diatoms KW - environmental filtering KW - phylogenetic diversity KW - Siberian tree line Y1 - 2020 U6 - https://doi.org/10.1111/jbi.13786 SN - 0305-0270 SN - 1365-2699 VL - 47 IS - 5 SP - 1166 EP - 1179 PB - Wiley-Blackwell CY - Oxford ER -