Cluster Human Health | Umweltbundesamt

On the relevance of the action field

The World Health Organisation (WHO) describes climate change as the ‘single biggest health threat facing humanity’: In many countries in the global south, climate change exacerbates the problems already caused by hunger and inadequate access to clean drinking water. However, climate change impacts are also on the increase in Germany where, owing to demographic change, they present our ageing society with problems.

This is why in 2022, the task force entitled Health Climate Pact (Klimapakt Gesundheit) published a joint declaration regarding its joint responsibility to counter the health impacts of climate change and to advance the public health system by improving health care in terms of climate adaptation, climate protection and sustainability.⁹

DAS Monitoring –what is happening due to climate change

Extreme weather and weather patterns have an immediate effect on health. Ever since the 1980s, there has been an increasing trend towards heat extremes (cf. Indicator GE-I-1). In extreme cases, heatwaves can cause mortality. In Germany alone, for example, it is estimated that between the years of 2018 and 2020, 19,300 individuals died from heat effects (cf. Indicator GE-I-2). In the past three decades, a slight decrease in the effect of high temperatures on mortality figures has been recorded.

Apart from heat-related health impairments, it is important to mention also pollen allergies, skin cancer caused by UV radiation as well as cardio-vascular and respiratory illnesses caused by air pollutants; all these health conditions have been linked to (non-infectious) illnesses which are regarded as associated with climate change. Nowadays, allergies are among the most frequent chronic diseases in Germany. Among these, pollen allergies play a particularly important role. Climatic changes influence the pollen season and the intensity of pollen burdens. Apart from grass pollen, various types of birch pollen are top of the ‘hit list’ as the cause of sensitisation among Germany’s population. As far as birches are concerned, some intensive research has been carried out studying the links to climate change. Especially in eastern Germany, the pollen concentration has been rising since records began in 1995 (cf. Indicator GE-I-3). So far, the pollen concentration of the introduced highly allergenic Annual Ragweed (Ambrosia artemisifolia, see Indicator GE-I-4) does not indicate any trend. However, the peak values identified repeatedly in eastern Germany are alarming; among other causes, these are attributed to long-distance transport from neighbouring south-eastern countries and/or to regional plant populations.

As far as cases of UV radiation (cf. Indicator GE-I-8) and air pollutants are concerned – the latter is linked in particular to near-ground ozone (cf. Indicator GE-I-9); the relationships with climate change are complex and not yet fully understood. Nevertheless, in both cases, the changed radiation scenarios and/or the changed radiation intensity are important factors. The health risk caused by UV radiation increases as a function of increased irradiation. Photochemical ozone generation is boosted in particular during prolonged periods of sunny weather. With this in mind, both of these themes have now been incorporated in the Monitoring Report for the first time.

Infectious diseases, too, are brought into context with climate change. As far as animal pathogen vectors such as mosquitoes, ticks or rodents are concerned, their living conditions can potentially improve under changed climatic conditions. This also holds true for the pathogens themselves, thus increasing the infection risks arising for humans and animals. The Asian Tiger mosquito is one example of a vector that is able to transmit hazardous pathogens. Owing to warmer weather patterns, this species is increasingly widening its distribution range and is able to hibernate, thus establishing populations (cf. Indicator GE-I-5).

Analogous to the Indicator entitled ‘Contamination of bathing water by cyanobacteria burdens’ describes hazards concerning bathing in lakes (cf. Indicator GE-I-6), the Monitoring Report now also presents an indicator covering health hazards to bathers in the sea in respect of vibrios (cf. Indicator GE-I-7). Especially in years with prolonged heatwaves, the extent of such loads becomes unusually high, thus distinctly increasing the risks to bathers.

Future climate risks – outcomes of KWRA

According to the 2021 Climate Impact and Risk Analysis the findings demonstrate that the impacts on health are even now causing high risks. In the run-up to the middle of this century, high risks are expected also in terms of health impacts from air-borne allergens and UV burdens. In addition, in the run-up to the end of this century, a high risk of respiratory problems owing to air pollution is expected, although this estimate is subject to low certainty.

The 2021 KWRA also analysed the impacts on the public health service. A high risk is expected to arise also in this sector by the end of the century. This means that presumably, but with low certainty, the health service will be facing a distinctly increased need for adaptation.

For the middle of this century, the risk of (a continued) spread of vector organisms – as well as potentially harmful microorganisms and algae – is assessed as medium (in a reference grid comprising the levels low – medium – high. This risk might lead to an increase in the incidence of certain vector-related) infectious diseases.

Likewise, the risk of increases in the number of injuries and mortalities resulting from extreme events is assessed as medium, albeit this assessment is subject to low certainty.

Where do we have gaps in data and knowledge?

In the 2023 Monitoring Report, the spectrum of the ‘Human Health’ action field was considerably widened by adding to the themes illustrated. Nevertheless, there are still difficulties in achieving a comprehensive reflection of the actual degree in which human beings are affected. The heat mortalities cover only the most extreme impacts of heatwaves whilst lack of data makes it impossible to quantify those illnesses that are a much more frequent outcome of heatwaves. With regard to other non-infectious and infectious diseases, it is difficult, to indicate any direct causal relationships with climate change impacts. Moreover, it is impossible to attribute the available data in a causal way. Hence, the focus of the Monitoring Indicators is on describing the potential risks at the impact level.

Despite the addition of new themes, it has not been possible to address several relevant climate risks in the context of DAS Monitoring, as there are certain gaps in research and also owing to the lack of data sources suitable for the development of indicators. However, there is also need for improving the datasets underpinning the themes addressed. In that context, the heat protection plan published in July 2023 by the Federal Ministry for Health (BMG) aims at improving the evidence for health impacts from heatwaves. In this context, the focus is on heat-related mortality and morbidity. Furthermore, there is a lack regarding the systematic and nationwide collection of data on the occurrence and spreading of vectors such as mosquitoes and ticks and the level of their infection with pathogens.

The issue to be researched is, as before, the question in what way and to what extent climate change will influence the quality of drinking water and foodstuffs in future. Work is also currently underway on the theme of fungal infections and in what way they are influenced by climate change¹⁰. Another focus of current research concerns the relationships between climate change and an increase in the resistance to antibiotics.

Climate change and the disasters ensuing from its impacts, which now occur with greater frequency and/or intensity, are not just putting physical health (including injuries) at risk; they can also entail various kinds of mental stress and disorders. However, the relationships of climate change and mental disorders have not yet been researched sufficiently to permit the presentation of concrete facts and figures in the current report.

Not least, climate change can entail high costs and new technical and organisational requirements to be covered by the public health service, as for instance, in terms of health care professionals, hospitals, emergency services or health insurance funds. These areas, too, require further research.

What’s being done – some examples

At the core of adaptation efforts in health-related areas are the nationwide networking of stakeholder groups, setting appropriate political frameworks, supporting the municipalities, as well as monitoring and transferring scientific findings to practical applications. Furthermore, Federal government has a strong commitment to the tasks of communication and raising public awareness, with the objective to motivate and empower citizens, in particular, any vulnerable groups such as the elderly or persons with existing medical conditions, thus enabling them to protect their own health.

Since 2021, the Federal Centre for Health Education (BZgA) has used the internet portal entitled ‘internetportal klima-mensch-gesundheit.de’ to provide information in respect of the impacts of climate change on human health. Citizens will also find quality-tested recommendations on appropriate behaviour and action for their own protection from heat and UV radiation on that website. The UBA provides information – in some cases jointly with the DWD – especially on themes such as heat¹¹ as well as air and water pollution. The Federal Office for Radiation Protection (BfS) provides information on UV radiation, its impacts, and in what way these are influenced by climate change, as well as potential protective measures. Apps and targeted newsletters have gained increasing importance; these provide information on risks (cf. Indicator GE-R-1) and in addition, individually tailored recommendations for action (cf. Indicator GE-R-3). The intensive public relations (PR) work has already made an impact. For example, there are distinct signs showing that the population’s awareness regarding the potential for heat affecting human health and wellbeing has increased (cf. Indicator GE-R-2).

Monitoring and the systematic, continuous surveillance of the health problems scenario are essential tools in facilitating current and future health risks. With its focus on climate monitoring and weather observation as well as climate projections, the DWD makes vital contributions to achieving this objective. The BfS coordinates the monitoring of UV radiation, while the UBA collects data on air quality and combines these data with data collected by the Länder. In addition, the UBA examines climate change impacts also in terms of ticks, rodents and mosquitoes as well as the infectious pathogens transmitted by them. In doing so, the UBA provides a model for a nationwide hantavirus prognosis, at the same time as working on measures for the sustainable management of vectors. Since 2023, the Robert Koch Institute (RKI) has been monitoring – every week in summer – the heat-related survivability; the RKI is responsible for implementing the reporting system in line with the Protection against Infections Act (IfSG) and has been advancing the surveillance of non-infectious diseases and health-related risk profiles. The Friedrich-Loeffler Institute (FLI) is active in the field of monitoring vector organisms; jointly with the Leibniz Centre for Agricultural Landscape Research (ZALF), it has been maintaining the ‘Mückenatlas’ (mosquito atlas) (cf. Indicator GE-R-4).

In its progress report ‘Klimawandel und Gesundheit’ (Climate change and health) published in 2023, the RKI has provided a comprehensive scientific overview of the health impacts of climate change as well as suggesting opportunities for counteracting those impacts. This report has coalesced contributions from a major number of (public) authorities, universities and research institutions¹²

Apart from communication activities and raising public awareness, there is also a need for the support of health services. For this purpose, the BMUV launched the funding programme ‘Climate adaptation in social institutions’ (Klimaanpassung in sozialen Einrichtungen) in 2020. It provides support for social institutions for the purpose of protecting themselves from climate change impacts such as heat, heavy rain or flooding. Although the programme was initially scheduled to run until 2023, its duration has now been extended beyond 2023 to 2026 on account of the enormous resonance it has encountered. An overview of further funding opportunities for health services in respect of climate adaptation, climate protection and resources efficiency in Germany was compiled on behalf of the BMG¹³.

Great need for action is seen at all levels, from Federal government down to municipalities. The generation of heat action plans has a high priority; the purpose of these plans is to prevent heat and UV-related impacts as well as medical complaints, and to reduce mortalities. The joint Federal/Länder government ad hoc working group entitled ‘Health-related adaptation to the impacts of climate change’ which is managed by the BMUV developed recommendations in 2017 – under the leadership of the UBA – for the design of municipal heat action plans. In March 2022, the BMUV initiated an emergency programme for climate adaptation developed for municipalities, which is also used for funding the development and implementation of heat action plans. In addition, and as requested by the Länder and leading municipal organisations, the Centre for Climate Adaptation (ZKA) founded – on behalf of the BMUV – an advisory programme for heat action plans. The Heat Service Portal [HitzeService-Portal (hitzeservice.de)] created on behalf of the BMG, is a platform to be used by municipalities for the planning and implementation of heat protection measures enabling these authorities to obtain tangible information and support.

^{9 - BMG – Bundesministerium für Gesundheit (Hg.) 2022: Klimapakt Gesundheit – gemeinsam für Klimaanpassung und Klimaschutz im Gesundheitswesen eintreten. Gemeinsame Erklärung des Bundesministeriums für Gesundheit, der Spitzenorganisationen im Gesundheitswesen sowie der Länder und kommunalen Spitzenverbände. Berlin, 7 pp. https://www.bundesgesundheitsministerium.de/fileadmin/Dateien/3_Downloads/G/Gesundheit/Erklaerung_Klimapakt_Gesundheit_A4_barrierefrei.pdf}

^{10 - Rickerts V. 2019: Climate change and systemic fungal infections. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 62(5): 646–651. doi: 10.1007/s00103-019-02931-z}

^{11 - Mücke H.-G., Matzarakis A. 2019: Klimawandel und Gesundheit: Tipps für sommerliche Hitze und Hitzewellen. Dessau-Roßlau, 10 pp. https://www.umweltbundesamt.de/publikationen/klimawandel-gesundheit-tipps-fuer-sommerliche-hitze}

^{12 - Adrian G., Dietrich M., Esser B., Hensel A., Isermeyer F., Messner D., Mettenleiter T.C., Paulini I., Riewenherm S., Schaade L., Tiesler R., Wieler L.H. 2023: Auswirkungen des Klimawandels auf Infektionskrankheiten und antimikrobielle Resistenzen – Teil 1 des Sachstandsberichts Klimawandel und Gesundheit 2023. Journal of Health Monitoring S3/2023. doi: 10.25646/11390}

^{13 - Überblick über Fördermöglichkeiten zum Klimaschutz und zur Klimaanpassung: https://www.pd-g.de/aktuell-im-fokus/nachhaltigkeit-im-gesundheitswesen}