Climate Change Effects on Heat Waves and Future Heat Wave-Associated IHD Mortality in Germany

Timing determines zooplankton community responses to multiple stressors

Human activities and climate change cause abiotic factors to fluctuate through time, sometimes passing thresholds for organismal reproduction and survival. Multiple stressors can independently or interactively impact organisms; however, few studies have examined how they interact when they overlap spatially but occur asynchronously. Fluctuations in salinity have been found in freshwater habitats worldwide. Meanwhile, heatwaves have become more frequent and extreme. High salinity pulses and heatwaves are often decoupled in time but can still collectively impact freshwater zooplankton. The time intervals between them, during which population growth and community recovery could happen, can influence combined effects, but no one has examined these effects. We conducted a mesocosm experiment to examine how different recovery times (0-, 3-, 6-week) between salt treatment and heatwave exposure influence their combined effects. We hypothesized that antagonistic effects would appear when having short recovery time, because previous study found that similar species were affected by the two stressors, but effects would become additive with longer recovery time since fully recovered communities would respond to heatwave similar to undisturbed communities. Our findings showed that, when combined, the two-stressor joint impacts changed from antagonistic to additive with increased recovery time between stressors. Surprisingly, full compositional recovery was not achieved despite a recovery period that was long enough for population growth, suggesting legacy effects from earlier treatment. The recovery was mainly driven by small organisms, such as rotifers and small cladocerans. As a result, communities recovering from previous salt exposure responded differently to heatwaves than undisturbed communities, leading to similar zooplankton communities regardless of the recovery time between stressors. Our research bolsters the understanding and management of multiple-stressor issues by revealing that prior exposure to one stressor has long-lasting impacts on community recovery that can lead to unexpected joint effects of multiple stressors.

Accounting for adaptation when projecting climate change impacts on health: A review of temperature-related health impacts

Exposure to high and low ambient temperatures can cause harm to human health. Due to global warming, heat-related health effects are likely to increase substantially in future unless populations adapt to living in a warmer world. Adaptation to temperature may occur through physiological acclimatisation, behavioural mechanisms, and planned adaptation. A fundamental step in informing responses to climate change is understanding how adaptation can be appropriately accounted for when estimating future health burdens. Previous studies modelling adaptation have used a variety of methods, and it is often unclear how underlying assumptions of adaptation are made and if they are based on evidence. Consequently, the most appropriate way to quantitatively model adaptation in projections of health impacts is currently unknown. With increasing interest from decisionmakers around implementation of adaptation strategies, it is important to consider the role of adaptation in anticipating future health burdens of climate change. To address this, a literature review using systematic scoping methods was conducted to document the quantitative methods employed by studies projecting future temperature-related health impacts under climate change that also consider adaptation. Approaches employed in studies were coded into methodological categories. Categories were discussed and refined between reviewers during synthesis. Fifty-nine studies were included and grouped into eight methodological categories. Methods of including adaptation in projections have changed over time with more recent studies using a combination of approaches or modelling adaptation based on specific adaptation strategies or socioeconomic conditions. The most common approaches to model adaptation are heat threshold shifts and reductions in the exposure-response slope. Just under 20% of studies were identified as using an intervention-based empirical basis for statistical assumptions. Including adaptation in projections considerably reduced the projected temperature-mortality burden in the future. Researchers should ensure that all future impact assessments include adaptation uncertainty in projections and assumptions are based on empirical evidence.

[Health and climate change-what is the potential of real-world data?]

This article addresses the question of how climate change may affect health and to what extent real-world data can contribute to research in this topic area. Climate change is altering the environmental and living conditions of humankind, and has thus also become a relevant health problem. The increase in extreme weather events, changes in exposure to UV and air pollution, and the climate-associated spread of allergens or novel pathogens are significantly changing the spectrum of diseases and the need for medical care in the population. However, in Germany, only few findings on the consequences for the healthcare system and on particularly affected population groups exist so far. Real-world data (primary data, register data, and administrative data) in combination with environmental exposure data and other relevant data (e.g., socio-economic data) have the potential to significantly advance research on the health consequences of climate change. This paper identifies changes in environmental and living conditions and associated health risks. It describes the databases that are generally available for analysing health effects of climate change. A concrete example is used to show how individual health data (in this case claims data of the statutory health insurance), environmental exposure data and other data can be successfully combined. Finally, the article offers a comprehensive overview of open research questions that can be answered with real-world data.

Universal Climate Thermal Index as a prognostic tool in medical science in the context of climate change: A systematic review

The assessment of the impact of meteorological factors on the epidemiology of various diseases and on human pathophysiology and physiology requires a comprehensive approach and new tools independent of currently occurring climate change. The thermal comfort index, i.e., Universal Climate Thermal Index (UTCI), is gaining more and more recognition from researchers interested in such assessments. This index facilitates the evaluation of the impact of cold stress and heat stress on the human organism and the assessment of the incidence of weather-related diseases. This work aims at identifying those areas of medical science for which the UTCI was applied for scientific research as well as its popularization among clinicians, epidemiologists, and specialists in public health management. This is a systematic review of literature found in Pubmed, Sciencedirect and Web of Science databases from which, consistent with PRISMA guidelines, original papers employing the UTCI in studies related to health, physiological parameters, and epidemiologic applications were extracted. Out of the total number of 367 papers identified in the databases, 33 original works were included in the analysis. The selected publications were analyzed in terms of determining the areas of medical science in which the UTCI was applied. The majority of studies were devoted to the broadly understood mortality, cardiac events, and emergency medicine. A significant disproportion between publications discussing heat stress and those utilizing the UTCI for its assessment was revealed.

Heat-Related Mortality in Germany From 1992 to 2021

BACKGROUND

2018-2020 were unusually warm years in Germany, and the summer of 2018 was the second warmest summer since record-keeping began in 1881. Higher temperatures regularly lead to increased mortality, particularly among the elderly.

METHODS

We used weekly data on all-cause mortality and mean temperature from the period 1992-2021 and estimated the number of heat-related deaths in all of Germany, and in the northern, central, and southern regions of Germany, employing a generalized additive model (GAM). To characterize long-term trends, we compared the effect of heat on mortality over the decades.

RESULTS

Our estimate reveals that the unusually high summer temperatures in Germany between 2018 and 2020 led to a statistically significant number of deaths in all three years. There were approximately 8700 heat-related deaths in 2018, 6900 in 2019, and 3700 in 2020. There was no statistically significant heat-related increase in deaths in 2021. A comparison of the past three decades reveals a slight overall decline in the effect of high temperatures on mortality.

CONCLUSION

Although evidence suggests that there has been some adaptation to heat over the years, the data from 2018-2020 in particular show that heat events remain a significant threat to human health in Germany.

Climate Impact and Model Approaches of Blue-Green Infrastructure Measures for Neighborhood Planning

Nowadays, most cities deal with the problem of “Urban Heat Islands”. Especially existing city districts cannot easily be adapted. In this paper, the effects of blue-green infrastructure elements (BGI) on air and surface temperature in courtyards are examined, based on on-site measurements and simulations. Recognizable effects on the temperature were observed: BGI lower the number of hot days in the courtyard, including a faster air temperature drop at night, but water elements increase the number of tropical nights due to their heat capacity. Model simulations with PALM-4U proved to be useful to analyze the effects of BGI on the microclimate. Besides analyzing existing structures, the effects of planned measures can be quantified by simulation. However, for this application, needs of improvement were recognized to evaluate the influence of BGI on the microclimate more realistically. For decision support, standard indicators such as the number of tropical nights and hot days are not differentiated enough to quantify specific climate stress of urban residents. It is suggested to consider summer days additionally, percentiles could be used instead of fixed thresholds and the entire course of the year should play a role in the evaluation of the elements and urban design.

Assessing the Spatial Mapping of Heat Vulnerability under Urban Heat Island (UHI) Effect in the Dhaka Metropolitan Area

The urban heat island (UHI) phenomenon gets intensified in the process of urbanization, which increases the vulnerability of urban dwellers to heatwaves. The UHI-induced vulnerability to heatwaves has increased in Bangladesh during past decades. Thus, this study aims to examine the UHI and vulnerability to heatwaves in the city of Dhaka using a heat vulnerability index (HVI). The HVI is constructed using various demographic, socioeconomic, and environmental risk variables at thana level. Principal component analysis (PCA) was applied to the 26 normalized variables for each of the 41 thanas of Dhaka to prepare the HVI. Result shows that more than 60% of the city is under built-up areas, while vegetation cover and water bodies are in low proportion. Analysis of HVI shows that the very high- and high-risk zones comprise 6 and 11 thanas, while low- and very low-risk zones comprise only 5 and 8 thanas. The correlation of HVI with variables such as exposure (0.62) and sensitivity (0.80) was found to be highly positive, while adaptive capacity had a negative correlation (−0.26) with the HVI. Findings of this study can be utilized in the mitigation of UHI phenomenon and maintaining the thermal comfort of Dhaka.

The Effect of Environmental Degradation, Climate Change, and the European Green Deal Tools on Life Satisfaction

Environmental issues, sustainability, and climate change have become the targets of many policies from international and governmental organizations including the EU’s European Green Deal action plan. This plan provides tools to address them—which include support for the circular economy, implementation of energy and environmental taxes, and investment in environmental protection—with the aim of favoring the well-being of EU citizens. In this context, this study analyses the impact of several parameters (environmental matters, global warming, circular economy, energy and environmental taxes, and expenditure and investment on the environment) on life satisfaction, or subjective well-being, and their effects on 33 European countries. For this purpose, four econometric models were carried out using data collected from the World Values Survey (WVS), the European Values Study (EVS), and the World Bank and Eurostat, reflecting subjective citizen satisfaction data. The findings present a highly significant inverse relationship between life satisfaction variables and both environmental problems and energy taxes. Additionally, there is a highly significant positive relationship between circular economy, environmental tax, and environmental protection expenditure parameters and life satisfaction variables, as well as, to a lesser degree of significance, with noise pollution from neighbours.

Heat-related mortality under climate change and the impact of adaptation through air conditioning: A case study from Thessaloniki, Greece

Climate change is expected to increase heat-related mortality across the world. Health Impact Assessment (HIA) studies are used to quantify the impact of higher temperatures, taking into account the effect of population adaptation. Although air-conditioning (AC) is one of the main drivers of technological adaptation to heat, the health impacts associated with AC-induced air pollution have not been examined in detail. This study uses the city of Thessaloniki, Greece as a case study and aims to estimate the future heat-related mortality, the residential cooling demand, and the adaptation trade-off between averted heat-related and increased air pollution cardiorespiratory mortality. Using temperature and population projections under different Coupled Model Intercomparison Project Phase 6 (CIMP6) Shared Socioeconomic Pathways scenarios (SSPs), a HIA model was developed for the future heat and air pollution cardiorespiratory mortality. Counterfactual scenarios of either black carbon (BC) or natural gas (NG) being the fuel source for electricity generation were included in the HIA. The results indicate that the heat-related cardiorespiratory mortality in Thessaloniki will increase and the excess of annual heat-related deaths in 2080-2099 will range from 2.4 (95% CI: 0.0-20.9) under SSP1-2.6 to 433.7 (95% CI: 66.9-1070) under SSP5-8.5. Population adaptation will attenuate the heat-related mortality, although the latter may be counterbalanced by the higher air pollution-related mortality due to increased AC, especially under moderate SSP scenarios and coal-fired power plants. Future studies examining the health effects of warmer temperatures need to account for the impact of both adaptation and increased penetration and use of AC.

Evaluation of Tourism-Climate Conditions in the Region of Kłodzko Land (Poland)

Kłodzko Land is one of the most important regions of Poland in terms of tourism and health issues. Numerous tourism attractions and health resorts make the region attractive for both tourist and bathers. The goal of this paper was to evaluate the impact of weather conditions on tourism-related conditions and their changes in the multiannual period. In the analysis, the indices of heat days, the UTCI (Universal Thermal Climate Index) and CTIS (Climate Tourism Information Scheme) tools were used. The research on heat days and the UTCI indicated a significant increase in the heat-stress frequency over the last decades. Simultaneously, the number of weather types related to cold stress has considerably decreased. Such trends were noticed in the entire region, in all the considered hypsometric zones. The rising tendency was also observed for strong and very strong heat stress (UTCI > 32 °C), which negatively affects health problems. The analysis showed that the most extreme thermal and biothermal conditions, in terms of heat stress, occur under southern and eastern anticyclonic circulation. The CTIS analysis showed that favorable weather conditions for most of tourism activities are noticed in the warm half-year. The usefulness of weather conditions for tourism can vary depending on atmospheric circulation.

Heat Extremes, Public Health Impacts, and Adaptation Policy in Germany

Global warming with increasing weather extremes, like heat events, is enhancing impacts to public health. This essay focuses on unusual extreme summer heat extremes occurring in Germany at higher frequency, longer duration, and with new temperature records. Large areas of the country are affected, particularly urban settlements, where about 77% of the population lives, which are exposed to multiple inner-city threats, such as urban heat islands. Because harm to public health is directly released by high ambient air temperatures, local and national studies on heat-related morbidity and mortality indicate that vulnerable groups such as the elderly population are predominantly threatened with heat-related health problems. After the severe mortality impacts of the extreme summer heat 2003 in Europe, in 2008, Germany took up the National Adaptation Strategy on Climate Change to tackle and manage the impacts of weather extremes, for example to protect people’s health against heat. Public health systems and services need to be better prepared to improve resilience to the effects of extreme heat events, e.g., by implementing heat health action plans. Both climate protection as well as adaptation are necessary in order to be able to respond as adequate as possible to the challenges posed by climate change.

Comparison of Respiratory and Ischemic Heart Mortalities and their Relationship to the Thermal Environment

Chronic respiratory and ischemic heart diseases are globally important parts of total mortality. This study focuses on the occurrence of mortality due to these disease groups in Germany and possible effects of the thermal environment. A retrospective analysis on the mortality rates of chronic lower respiratory diseases (CLRD) and ischemic heart diseases (IHD) at the regional level in Germany for the period 2001–2015 was done in combination with meteorological observations from the network of the German Meteorological Service. In order to control the mortality data for long-term and seasonal trends, a 365-day Gaussian low-pass filter with a filter response function was applied. The thermal environment was analysed using 2 m air temperature (Ta) and the human biometeorological index Perceived Temperature (PT). The relationship of the Relative Risk (RR) of mortality to the thermal environment is displayed as an exposure–response curve, with threshold values at which RR increases significantly towards higher and lower temperature values. CLRD mortality increases above 17.6 °C, at approximately 4.4%/°C (CI: ± 0.3). The increase of IHD mortality above the threshold of 18.8 °C is less steep, at 3.5%/°C (CI: ± 0.2). During hot periods, CLRD mortality increases by 19.9%, which is twice as much as IHD mortality, with an increase of 9.8%. However, cold days and cold periods affect IHD slightly more than CLRD. The results highlight the concerns of CLRD patients during hot days as well as heat waves. This could lead to better precautions being taken for respiratory patients, which are already established for cardiac patients in Germany.

Projection of mortality attributed to heat and cold; the impact of climate change in a dry region of Iran, Kerman

BACKGROUND

Estimating the effects of climate change on human health can help health policy makers plan for the future. In Iran, there are few studies, about investigating the effects of climate change on mortality. This study aimed to project the effect of low (cold) and high (heat) temperature on mortality in a dry region of Iran, Kerman.

METHODS

Mortality attributed to temperature was projected by estimating the temperature-mortality relation for the observed data, projection of future temperatures by the statistical downscaling model (SDSM), and quantifying the attributable fraction by applying the observed temperature-mortality relation on the projected temperature. Climate change projection was done by three climate scenarios base on Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5). Adaptation was considered by using different minimum mortality temperatures (MMT) and risk reduction approaches. The current decade (2010-19) was considered as the reference period.

RESULTS

All three climate change scenarios, showed that the mean of temperature will rise about 1 °C, by 2050 in Kerman. The number of deaths attributed to heat were obviously higher than cold in all periods. Assuming no adaptation, over 3700 deaths attributed to temperature will happen in each decade (2020s, 2030s and 2040s) in the future, in which over 3000 deaths will be due to heat and over 450 due to cold. In the predictions, as Minimum Mortality Temperature (MMT) went up, the contribution of heat to mortality slightly decreased, and cold temperature played a more important role. By considering the risk reduction due to adaptation, the contribution of heat in mortality slightly and insignificantly decreased.

CONCLUSION

The results showed that although low temperatures will contribute to temperature-related mortality in the future, but heat will be a stronger risk factor for mortality, especially if adaptation is low.

Heatwaves in the Future Warmer Climate of South Africa

Weather and climate extremes, such as heat waves (HWs), have become more frequent due to climate change, resulting in negative environmental and socioeconomic impacts in many regions of the world. The high vulnerability of South African society to the impacts of warm extreme temperatures makes the study of the effect of climate change on future HWs necessary across the country. We investigated the projected effect of climate change on future of South Africa with a focus on HWs using an ensemble of regional climate model downscalings obtained from the Conformal Cubic Atmospheric Model (CCAM) for the periods 2010–2039, 2040–2069, and 2070–2099, with 1983–2012 as the historical baseline. Simulations were performed under the Representative Concentration Pathway (RCP) 4.5 (moderate greenhouse gas (GHG) concentration) and 8.5 (high GHG concentration) greenhouse gas emission scenarios. We found that the 30-year period average maximum temperatures may rise by up to 6 °C across much of the interior of South Africa by 2070–2099 with respect to 1983–2012, under a high GHG concentration. Simulated HW thresholds for all ensemble members were similar and spatially consistent with observed HW thresholds. Under a high GHG concentration, short lasting HWs (average of 3–4 days) along the coastal areas are expected to increase in frequency in the future climate, however the coasts will continue to experience HWs of relatively shorter duration compared to the interior regions. HWs lasting for shorter duration are expected to be more frequent when compared to HWs of longer durations (over two weeks). The north-western part of South Africa is expected to have the most drastic increase in HWs occurrences across the country. Whilst the central interior is not projected to experience pronounced increases in HW frequency, HWs across this region are expected to last longer under future climate change. Consistent patterns of change are projected for HWs under moderate GHG concentrations, but the changes are smaller in amplitude. Increases in HW frequency and duration across South Africa may have significant impacts on human health, economic activities, and livelihoods in vulnerable communities.

[Estimation of heat-related deaths in Germany between 2001 and 2015]

BACKGROUND

During the summers of 2003 and 2015, heat was found to be the cause of a substantial number of deaths in Germany. Until now, estimates for the total number of heat-related deaths were only available regionally in Germany. For the summer of 2003, an analysis for Baden-Württemberg was extrapolated to the whole of Germany.

OBJECTIVES

Our analysis tries to prove a stable statistical relationship between heat and mortality and to use this to quantify the number of heat-related deaths in Germany between the years 2001 and 2015.

MATERIALS AND METHODS

By fitting a nonlinear statistical model, we estimated exposure-response curves that describe the influence of heat on the mortality rate. The performance of different indicators for heat stress was compared.

RESULTS

The comparison of the different indicators for heat showed that the weekly mean temperature was most useful to explain the course of the weekly mortality during the summer. The relation between mortality rate and weekly mean temperature varied between age groups and regions in Germany (north, middle, south). The age groups (75-84) and (85+) were most affected by heat. The highest number of heat-related deaths was 7600 (95% CI 5500-9900), found for the summer 2003, followed by 6200 (4000; 8000) in the summer 2006 and 6100 (4000; 8300) in the summer 2015.

CONCLUSIONS

We could show that even in weekly data on mortality, a clear influence of heat could be identified. A national surveillance of mortality that allows real-time monitoring would be desirable.

[Epidemiology and prevention of heat-related adverse health effects on elderly people]

Heat waves increase the morbidity and mortality in Germany, particularly of older patients in need of care. Due to climate change the number of heat waves in Germany will increase threefold by the end of the century. In addition, the proportion of patients at risk will grow due to demographic change. Therefore, the Government and the Federal States have developed recommendations for heat action plans, in which the medical profession should also participate in the prevention of heat-related damage to health. Physicians and their team should first become acquainted with the topic. In addition, they should inform patients at risk and their relatives of the risks and preventive measures. In the summer a critical check of drugs is also needed because medications impair cooling mechanisms in heat waves, the pharmacokinetics can change and unwanted side effects of drugs occur more frequently. Lastly, due to their central position in the healthcare system, physicians should participate in the coordination of a good nursing care and intensification of social contacts during heat waves.

The Future of Climate Epidemiology: Opportunities for Advancing Health Research in the Context of Climate Change

In the coming decades, climate change is expected to dramatically affect communities worldwide, altering the patterns of many ambient exposures and disasters, including extreme temperatures, heat waves, wildfires, droughts, and floods. These exposures, in turn, can affect risks for a variety of human diseases and health outcomes. Climate epidemiology plays an important role in informing policy related to climate change and its threats to public health. Climate epidemiology leverages deep, integrated collaborations between epidemiologists and climate scientists to understand the current and potential future impacts of climate-related exposures on human health. A variety of recent and ongoing developments in climate science are creating new avenues for epidemiologic contributions. Here, we discuss the contributions of climate epidemiology and describe some key current research directions, including research to better characterize uncertainty in climate health projections. We end by outlining 3 developing areas of climate science that are creating opportunities for high-impact epidemiologic advances in the near future: 1) climate attribution studies, 2) subseasonal to seasonal forecasts, and 3) decadal predictions.

Impact of Atmospheric Circulation on the Occurrence of Hot Nights in Central Europe

The main goal of the study is to determine the pressure conditions that cause waves of hot nights in Central Europe. The goal was implemented on the basis of data from 1966 to 2015, made available by the Institute of Meteorology and Water Management—National Research Institute, Deutscher Wetterdienst and the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR). A hot night was defined as a day with the minimum air temperature above 18 °C. In the analysed years, an increase in the number of hot nights was found, which was predominantly statistically significant within the studied area. The study shows that the occurrence of waves of hot nights in Central Europe was associated on average with the ridge of high pressure, within which a local high-pressure area developed. During the waves of hot nights, there were positive anomalies of heights of isobaric surfaces over the study area with a maximum in the upper troposphere.

General Practitioners' Perceptions of Heat Health Impacts on the Elderly in the Face of Climate Change-A Qualitative Study in Baden-Württemberg, Germany

Heat health impacts (HHI) on the elderly are a growing concern in the face of climate change and aging populations. General practitioners (GPs) have an important role in health care for the elderly. To inform the development of effective prevention measures, it is important to investigate GPs’ perceptions of HHI. Twenty four qualitative expert interviews were conducted with GPs and analyzed using the framework approach. GPs were generally aware of heat health impacts, focusing on cardiovascular morbidity and volume imbalances. Perceptions of mortality and for instance impacts on respiratory diseases or potentially risky drugs in heat waves partly diverged from findings in literature. GPs judged the current relevance of HHI differently depending on their attitudes towards: (i) sensitivity of the elderly, (ii) status of nursing care and (iii) heat exposure in Baden-Württemberg. Future relevance of HHI was perceived to be increasing by most GPs. The main cause identified for this was population aging, while impacts of climate change were judged as uncertain by many. GPs’ perceptions, partly diverging from literature, show that GPs’ knowledge and awareness on HHI and climate change needs to be strengthened. However, they also emphasize the need for more research on HHI in the ambulant health care setting. Furthermore, GPs perceptions suggest that strong nursing care and social networks for elderly are major elements of a climate resilient health system.

[Climate change - physical and mental consequences]

Climate change has already had a large influence on the human environmental system and directly or indirectly affects physical and mental health. Triggered by extreme meteorological conditions, for example, storms, floods, earth slides and heat periods, the direct consequences range from illnesses to serious accidents with injuries, or in extreme cases fatalities. Indirectly, a changed environment due to climate change affects, amongst other things, the cardiovascular system and respiratory tract, and can also cause allergies and infectious diseases. In addition, increasing confrontation with environmental impacts may cause negative psychological effects such as posttraumatic stress disorders and anxiety, but also aggression, distress and depressive symptoms. The extent and severity of the health consequences depend on individual pre-disposition, resilience, behaviour and adaptation.

The Summers 2003 and 2015 in South-West Germany: Heat Waves and Heat-Related Mortality in the Context of Climate Change

After 2003, another hot summer took place in Western and Central Europe in 2015. In this study, we compare the characteristics of the two major heat waves of these two summers and their effect on the heat related mortality. The analysis is performed with focus on South-West Germany (Baden–Württemberg). With an additional mean summer mortality of +7.9% (2003) and +5.8% (2015) both years mark the top-two records of the summer mortality in the period 1968–2015. In each summer, one major heat wave contributed strongly to the excess summer mortality: In August 2003, daily mortality reached anomalies of +70% and in July 2015 maximum deviations of +56% were observed. The August 2003 heat wave was very long-lasting and characterized by exceptional high maximum and minimum temperatures. In July 2015, temperatures were slightly lower than in 2003, however, the high air humidity during the day and night, lead to comparable heat loads. Furthermore, the heat wave occurred earlier during the summer, when the population was less acclimated to heat stress. Using regional climate models we project an increasing probability for future 2003- and 2015-like heat waves already in the near future (2021–2050), with a 2015-like event occurring about every second summer. In the far future (2070–2099) pronounced increases with more than two 2015-like heat waves per summer are possible.

Biometeorological Assessment of Mortality Related to Extreme Temperatures in Helsinki Region, Finland, 1972-2014

Climate change is expected to increase heat-related and decrease cold-related mortality. The extent of acclimatization of the population to gradually-changing thermal conditions is not well understood. We aimed to define the relationship between mortality and temperature extremes in different age groups in the Helsinki-Uusimaa hospital district in Southern Finland, and changes in sensitivity of the population to temperature extremes over the period of 1972-2014. Time series of mortality were made stationary with a method that utilizes 365-day Gaussian smoothing, removes trends and seasonality, and gives relative mortality as the result. We used generalized additive models to examine the association of relative mortality to physiologically equivalent temperature (PET) and to air temperature in the 43-year study period and in two 21-year long sub-periods (1972-1992 and 1994-2014). We calculated the mean values of relative mortality in percentile-based categories of thermal indices. Relative mortality increases more in the hot than in the cold tail of the thermal distribution. The increase is strongest among those aged 75 years and older, but is somewhat elevated even among those younger than 65 years. Above the 99th percentile of the PET distribution, the all-aged relative mortality decreased in time from 18.3 to 8.6%. Among those ≥75 years old, the decrease in relative mortality between the sub-periods were found to be above the 90th percentile. The dependence of relative mortality on cold extremes was negligible, except among those ≥75 years old, in the latter period. Thus, heat-related mortality is also remarkable in Finland, but the sensitivity to heat stress has decreased over the decades.

Adaptation to Climate Change: A Comparative Analysis of Modeling Methods for Heat-Related Mortality

BACKGROUND

Multiple methods are employed for modeling adaptation when projecting the impact of climate change on heat-related mortality. The sensitivity of impacts to each is unknown because they have never been systematically compared. In addition, little is known about the relative sensitivity of impacts to "adaptation uncertainty" (i.e., the inclusion/exclusion of adaptation modeling) relative to using multiple climate models and emissions scenarios.

OBJECTIVES

This study had three aims: a) Compare the range in projected impacts that arises from using different adaptation modeling methods; b) compare the range in impacts that arises from adaptation uncertainty with ranges from using multiple climate models and emissions scenarios; c) recommend modeling method(s) to use in future impact assessments.

METHODS

We estimated impacts for 2070-2099 for 14 European cities, applying six different methods for modeling adaptation; we also estimated impacts with five climate models run under two emissions scenarios to explore the relative effects of climate modeling and emissions uncertainty.

RESULTS

The range of the difference (percent) in impacts between including and excluding adaptation, irrespective of climate modeling and emissions uncertainty, can be as low as 28% with one method and up to 103% with another (mean across 14 cities). In 13 of 14 cities, the ranges in projected impacts due to adaptation uncertainty are larger than those associated with climate modeling and emissions uncertainty.

CONCLUSIONS

Researchers should carefully consider how to model adaptation because it is a source of uncertainty that can be greater than the uncertainty in emissions and climate modeling. We recommend absolute threshold shifts and reductions in slope. https://doi.org/10.1289/EHP634.

The use of climate information to estimate future mortality from high ambient temperature: A systematic literature review

BACKGROUND AND OBJECTIVES

Heat related mortality is of great concern for public health, and estimates of future mortality under a warming climate are important for planning of resources and possible adaptation measures. Papers providing projections of future heat-related mortality were critically reviewed with a focus on the use of climate model data. Some best practice guidelines are proposed for future research.

METHODS

The electronic databases Web of Science and PubMed/Medline were searched for papers containing a quantitative estimate of future heat-related mortality. The search was limited to papers published in English in peer-reviewed journals up to the end of March 2017. Reference lists of relevant papers and the citing literature were also examined. The wide range of locations studied and climate data used prevented a meta-analysis.

RESULTS

A total of 608 articles were identified after removal of duplicate entries, of which 63 were found to contain a quantitative estimate of future mortality from hot days or heat waves. A wide range of mortality models and climate model data have been used to estimate future mortality. Temperatures in the climate simulations used in these studies were projected to increase. Consequently, all the papers indicated that mortality from high temperatures would increase under a warming climate. The spread in projections of future climate by models adds substantial uncertainty to estimates of future heat-related mortality. However, many studies either did not consider this source of uncertainty, or only used results from a small number of climate models. Other studies showed that uncertainty from changes in populations and demographics, and the methods for adaptation to warmer temperatures were at least as important as climate model uncertainty. Some inconsistencies in the use of climate data (for example, using global mean temperature changes instead of changes for specific locations) and interpretation of the effects on mortality were apparent. Some factors which have not been considered when estimating future mortality are summarised.

CONCLUSIONS

Most studies have used climate data generated using scenarios with medium and high emissions of greenhouse gases. More estimates of future mortality using climate information from the mitigation scenario RCP2.6 are needed, as this scenario is the only one under which the Paris Agreement to limit global warming to 2°C or less could be realised. Many of the methods used to combine modelled data with local climate observations are simplistic. Quantile-based methods might offer an improved approach, especially for temperatures at the ends of the distributions. The modelling of adaptation to warmer temperatures in mortality models is generally arbitrary and simplistic, and more research is needed to better quantify adaptation. Only a small number of studies included possible changes in population and demographics in their estimates of future mortality, meaning many estimates of mortality could be biased low. Uncertainty originating from establishing a mortality baseline, climate projections, adaptation and population changes is important and should be considered when estimating future mortality.

The reproductive potential and importance of key management aspects for successful Calluna vulgaris rejuvenation on abandoned Continental heaths

The abandonment of traditional pastoralism as well as the use of heath areas for military purposes has had a major impact on dry heaths in the Continental biogeographical region of Europe, causing severe degradation of its key species Calluna vulgaris (L.) HULL. The reproductive potential of this species in a Continental climate is assumed to be low, although there is yet no observational or experimental evidence for this. More knowledge is also needed about cost-effective and sustainable measures to restore abandoned dry heaths in this biogeographical region, because traditional management options are often too expensive (e.g., sod-cutting) or restricted due to environmental laws and the danger of unexploded ammunition (e.g., burning). Using as an example an 800 ha Continental heathland in Germany that has been abandoned for about two decades, we studied the reproductive potential (seed production, soil seed bank, and germination ability) of degenerate C. vulgaris stands. In addition, we conducted a comprehensive field experiment to test the effects of low-intensity, year-round grazing by Heck cattle and Konik horses as well as one-time mowing and patchy exposure of bare soil on the generative rejuvenation (i.e., recruitment and survival) of degenerate C. vulgaris stands over 3 years. We used generalized linear mixed models for statistical analyses. Seed production of degenerate C. vulgaris stands was high as well as the germination ability of their seeds, being similar to Atlantic heathlands. However, soil seed-bank densities were lower than those found in managed or abandoned Atlantic heaths. Overall seedling recruitment in the field was considerably lower in comparison with Atlantic heaths. Low-intensity grazing or one-time mowing did not induce a substantial increase in C. vulgaris recruitment, whereas an additional one-time creation of bare soil patches or the one-time creation of bare soil without subsequent management significantly facilitated seedling recruitment and survival in the first year. However, from the second year on, the positive effect of the creation of bare soil without subsequent management was no longer present. In the third year, survival of juveniles was significantly supported by low-intensity grazing in combination with shallow soil disturbances as well as in combination with one-time mowing and shallow soil disturbances, whereas mowing alone resulted in marginally significant lower survival. The extremely low seedling recruitment requires a careful choice of suitable management measures to promote the survival of sufficient numbers of Calluna individuals. Therefore, we recommend low-intensity grazing with free-ranging robust breeds and the combination of this with one-time mowing as an effective means of supporting generative rejuvenation of C. vulgaris in degraded heaths. However, at the beginning of the restoration process, the creation of bare soil patches for seedling recruitment is crucial. For implementation into practice, we present different strategies to enhance the proportion of bare soil after long-term abandonment of heaths when traditional management options are no longer feasible.

Global climate change: impact of heat waves under different definitions on daily mortality in Wuhan, China

Background

There was no consistent definition for heat wave worldwide, while a limited number of studies have compared the mortality effect of heat wave as defined differently. This paper aimed to provide epidemiological evidence for policy makers to determine the most appropriate definition for local heat wave warning systems.

Methods

We developed 45 heat wave definitions (HWs) combining temperature indicators and temperature thresholds with durations. We then assessed the impact of heat waves under various definitions on non-accidental mortality in hot season (May–September) in Wuhan, China during 2003–2010.

Results

Heat waves defined by HW14 (daily mean temperature ≥ 99.0th percentile and duration ≥ 3 days) had the best predictive ability in assessing the mortality effects of heat wave with the relative risk of 1.63 (95% CI: 1.43, 1.89) for total mortality. The group-specific mortality risk using official heat wave definition of Chinese Meteorological Administration was much smaller than that using HW14. We also found that women, and the elderly (age ≥ 65) were more susceptible to heat wave effects which were stronger and longer lasting.

Conclusion

These findings suggest that region specific heat wave definitions are crucial and necessary for developing efficient local heat warning systems and for providing evidence for policy makers to protect the vulnerable population.

Electronic supplementary material

The online version of this article (doi:10.1186/s41256-017-0030-2) contains supplementary material, which is available to authorized users.