What are the impacts of climate change and how do we adapt?
Climate change and its consequences are already noticeable in Germany. The hot and dry summers of 2018 and 2019 as well as the heavy-rain events of 2016 and 2017 have resulted in raising public awareness of climate change. Consequences for human health, agriculture and forestry as well as private and public buildings and infrastructures have become more obvious, and climate change also triggers dynamic adaptation processes in nature (e.g. the displacement or immigration of animal and plant species) which in turn impact on humans and their economic activities. A total of c. 1,200 heat-related mortalities were recorded for summer 2018 in Berlin and Hesse by the Robert Koch-Institut (RKI/Robert Koch Institute). Drought also impacted on agriculture: Drought aid amounting to 340 million Euros was made available at Federal and Länder level. At the same time the GDV (German association of members of the insurance industry/Gesamtverband der Deutschen Versicherungswirtschaft e.V.) states an amount for 2018 of 2.8 billion Euros in terms of insured damage to buildings as well as trade and industrial enterprises. caused by storms, hailstones and heavy rain.
These losses make clear how urgent it is to take action, both in respect of protection from climate change and adaptation to the consequences of climate change. Even if humanity succeeds in limiting global warming in accordance with the climate targets agreed at the Paris Conference, our climate will continue to change. It is essential to make concerted efforts and to apply a co-ordinated approach to actions at all government levels in order to create the prerequisites for adaptation to the consequences of climate change in Germany.
In this light, the Federal government has, as early as 2008, under the auspices of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, submitted the Deutsche Anpassungsstrategie an den Klimawandel (DAS/German Strategy for Adaptation to Climate Change) which has been continually advanced ever since. This strategy provides the framework at Federal level for formulating policies regarding adaptation to climate change. The objective is to reduce the vulnerability of German society, economy and environment and to increase the country’s freedom to act. In 15 central action areas the essential requirements for action are listed, and (within relevant competences) the concrete steps and measures taken at Federal level are described (in alphabetical order): Building Industry, Biodiversity, Soil, Energy Industry, Financial Services Sector, Fisheries Woodland and Forestry, Trade and Industry, Agriculture, Human Health, Tourism Industry, Transport and Transport Infrastructure, Water Regime, Water Management, Coastal and Marine Protection as well as cross-sectional activities such as Civil Protection as well as Spatial Planning, Regional and Urban Development. This work was carried out in close collaboration with administrations at Länder (Federal States of Germany) and municipal level.
The DAS is a well-established, ongoing long-term task. It is based on an inter-agency network consisting of 28 Federal Government agencies, e.g. the Umweltbundesamt (UBA/German Environment Agency), the Deutsche Wetterdienst (DWD/German Meteorological Service), the Bundesamt für Bevölkerungsschutz und Katastrophenhilfe (BBK/Federal Office of Civil Protection and Disaster Assistance), the Bundesinstitut für Bau-, Stadt- und Raumforschung (BBSR/Federal Institute for Research on Building, Urban Affairs and Spatial Development), the Bundesanstalt Technisches Hilfswerk (THW/Federal Agency for Technical Relief) and the Bundesanstalt für Gewässerkunde (BfG/Federal Institute of Hydrology). This network incorporates a continuous reporting system.
As required by the DAS framework, the Federal Government now presents its second report, i.e. the 2019 Monitoring Report. This Report underpins the impacts of climate change with solid scientific data, at the same time as providing the public as well as decisionmakers in all sectors of society with information on tangible impacts of climate change. The 2019 Monitoring Report therefore represents an update of the 2015 Monitoring Report. Future updates are to be carried out every four years. Indicators and measured data selected from the 15 action areas by experts were incorporated in the Report in order to demonstrate any climate-related changes which have already become apparent in present-day Germany; the Report also features any measures that were taken to counteract this trend. The consequences of temperature rise can already be seen, for instance, in terms of obvious impacts on uncultivated ecosystems (such as changes in seasonal phenology leading to extended growing seasons, as well as incipient changes in the composition of tree species in natural woodland reserves). The Monitoring Report furthermore shows evidence for precautionary efforts made at Federal Government level in view of increasing risks. The Report also makes clear that it is of vital importance to intensify our efforts in respect of protection from climate change in order to limit its impacts, at the same time taking action to adapt to climate change. This is essential in order to find effective ways of countering the unavoidable risks arising in ecological, social and economic terms and to minimise losses.
For this very reason, the Federal Government undertakes regular reviews of the DAS and subjects it to further development based on progress reports which are enacted every five years at Cabinet level. Action plan measures are agreed in conjunction with these progress reports. The next progress report on DAS is expected to be submitted in autumn 2020; it will contain the findings of the 2019 Monitoring Report.
The work was supported and approved at Federal Government level under the auspices of the Bundesministerium für Umwelt, Naturschutz und nukleare Sicherheit (BMU/Federal Ministry for the Environment, Nature Conservation and Nuclear Safety) within the Interministerial Working Group on Adaptation to Climate Change (IMAA). This working group incorporates representatives from nearly all federal ministries and the scientific agencies assigned to them. The Report and the underlying indicator system were developed with contributions from numerous experts in competent agencies at Federal and State level and from scientific establishments and private institutes. The work was organised by the UBA’s department Fachgebiet KomPass – Klimafolgen und Anpassung in Deutschland (climate impacts and adaptation in Germany), acting as administrative office.
The Reporting Period 2014–2017 of the second, i.e. the 2019 Monitoring Report on DAS was characterised by a series of very warm years with extended droughts and violent downpours of heavy rain. The 2019 Monitoring Report on DAS does not contain a systematic indication of data from 2018 and 2019, because the processing of nationwide, statistically backed data tend to involve delays. Rather than illustrating the latest up-to-date developments, the ongoing monitoring under DAS focuses on the systematic observation of climate impacts and adaptation, on the basis of statistically well-founded time series. Nevertheless, as far as possible, an initial estimate of developments in 2018/19 was included in some texts of the report.
Increasing heat stress
The summers of 2003, 2018 and 2019 were the warmest in Germany since meteorological records in this country began. The annual air temperature as an aggregated mean for Germany between 1881 and 2018 was determined statistically to have risen by 1.5°C. In the course of past decades, there is evidence for a trend towards extreme weather events marked by increasing heat extremes. In particular, the number of ‚hot days’ on which the highest measured temperature amounted to 30°C or more, has gone up significantly (Indicator GE-I-1). Based on nationwide data in 2003 the number of people dying from heat-related conditions was higher by 7,500 mortalities than would have been expected in the absence of a heatwave. For the years 2006 and 2015 respectively, approx. 6,000 additional mortalities were recorded (GEI-2). Apart from preventative measures to protect human health, adaptation is also implemented at planning and construction levels, in order to reduce heat stress, especially in urban contexts (BAU-I-1, BAU-I-2, BAU-R-1, BAU-R-2, RO-R-4). Likewise, public awareness of health impacts from periods of great heat is on the increase, as demonstrated by the uptake of warning and information services and indicated by the outcomes of representative surveys (HUE-2, GE-I-1, GE-R-1, GE-R-3, BS-R-1)
Adverse effects on water usage owing to increased warming and more frequent summer droughts
The data of groundwater levels selected from nationwide statistics indicate that, in comparison with the long-term annual mean, the frequency of months with low groundwater levels below average has been increasing significantly (WW-I-1). In particular, precipitation deficits occurring in the course of several consecutive years led to reductions in groundwater levels or reduced spring flow in the years between 2013 and 2017. In view of a distinctly dry period, the data for 2018 point to the likelihood of a similar, presumably even more extreme situation arising.
The time series beginning in the 1960s for the mean flow levels of 80 river areas across Germany indicates distinct fluctuations between the years. For the hydrological winter season from early November till end of April, no statistically significant trend was discernible for the mean flow level. However, during the summer season, the flow level mean clearly drops significantly. This suggests a decrease in water availability during summer (WW-I-2). The difficult situation with regard to soil water supply (BO-I-1) as reported in 2015, is continuing. Agricultural management techniques have to be adapted in a way as to augment the soil’s humus supply and to boost the soil water supply, in order to ensure being better prepared for drought periods. Between 2000 and 2017, climate change impacts were increasingly taken into account in aspects of landscape planning (in UK known as town and country planning) and in other specific fields of planning, e.g. the designation of surface areas for preventive flood protection (BD-R-1, RO-R-3).
Damage from heavy rain and flash floods in urban areas
For the first time, illustrations of heavy rain events in residential areas (BAU-I-4) have been incorporated in the 2019 DAS Monitoring Report. This is to focus the DAS Monitoring process more precisely on the outcomes of the vulnerability analysis which in 2015 identified heavy rain and flash floods as strategic focal points. One precaution against losses from heavy rain and flash floods in urban areas is incorporated in DAS Monitoring by means of addressing the density of extended insurance cover for damage from natural hazards. The data show that although the insurance density has increased significantly in recent years, looking at it nationwide, it is still relatively low, i.e. with 43% for building insurance and with 24% for building contents insurance.
Floodwater and river flooding
The development of floodwater days does not show any significant trends for the time series, either for the summer or for the winter season (WW-I-3). The development of floodwater is always related to specific combinations of weather conditions which have so far not occurred either systematically, regularly or repeatedly. One example of this are so-called Vb (or Five-B) weather conditions which e.g. caused the river Elbe to flood in 2002 as well as causing other floodwater events. The distribution of floodwater days impacting on hydrological winter and summer seasons has so far not indicated a trend. Apart from climate change, there are however numerous other developments which affect the phenomenon of floodwater events.
Sea level rise and storm surges
The levels of North Sea and Baltic Sea covered in the 2019 DAS Monitoring Report indicate a predominantly significant rise in sea levels (WW-I-8). The increasing intensity of storm surges (WW-I-9) can be attributed mostly to sea level rise. For coastal regions, especially for estuaries and low-lying coastal areas, this signifies a gradually increasing threat.
Changes in species composition and natural development phases resulting from gradual temperature rise
Rising temperatures also affect natural systems. As a result, the duration of the growing period has increased further since submission of the 2015 DAS Monitoring Report (BD-I-1). A comparison shows that e.g. characteristic development phases of wild plants (such as unfolding of leaves, development of flower buds or fruiting bodies in spring, summer or early autumn, begin earlier, and typical development phases at the height of autumn, in late autumnn and winter begin later than before. Changes in seasonal weather phases can have both positive and negative effects on agriculture. An earlier onset of apple blossom, for example, signifies a greater risk of late frost damage which can result in crop shortfalls or failures (LW-I-1).
Likewise, in ecosystems hardly affected by management activities, the greater frequency of warm and dry years demonstrates a distinct impact. For example, the content of beech trees compared to species better adapted to droughts in warm-dry natural woodland reserves has decreased (FW-I-1). The current condition of woodlands and forests and any changes since the last National Forest Inventory recorded in 2012 will not be available for consideration in the third monitoring report until after the next National Forest Inventory in 2022. Any impacts from increasing warming are also noticeable in significantly increased water temperatures in lakes (WW-I-5) and in the North Sea (WW-I-7).
Even if the annual mean temperatures rise continuously, impacts on ecosystems from long, cold winters will remain active. This is illustrated by the development of bird species communities (BD-I-2). Since 1990 the composition of bird species communities has shifted in favour of thermophilic species. In the years 2009/10 to 2012/13 there were a number of hard winters with adverse impacts on the numbers of many breeding birds. These hard winters particularly affected species which had migrated to Germany from more southerly climate zones.