Dealing with Climate Change – What Berlin and London Can Learn from Each Other

Summary

The hot summer of 2026 showed that climate change is not a distant scenario. Extreme heat, drought, wildfires, low water levels, and crop failures cause health-related and economic damage. Older and sick people, as well as residents of densely built-up neighborhoods, are especially at risk. At the same time, transport disruptions, production outages, and damage to infrastructure place a burden on businesses and public budgets.

For the roughly 11,000 municipalities in Germany, a twofold task arises: they must reduce their greenhouse gas emissions and at the same time prepare for the unavoidable consequences of global warming. These measures are considered voluntary municipal tasks, however. Staffing and funding are therefore not secured.

Berlin and London demonstrate two different political responses. Berlin pursues an integrated, spatially oriented approach that connects climate mitigation and climate adaptation. London combines a very ambitious climate target with clear sectoral priorities, but has also published an urban development plan, a complementary resilience strategy with climate dimensions, and a heat plan. Neither of the two capital-city strategies can be transferred unchanged to all German municipalities. A promising path is to combine their strengths: plan comprehensively, fund priority measures in a binding way, measure results as quantitatively as possible, and gradually scale up successful projects.

Municipal Climate Policy Under Pressure to Act

The central question is no longer whether municipalities must act. What matters is how quickly and systematically they can act, and which legal and financial conditions they need in order to do so. Climate mitigation and climate adaptation therefore belong at the core of responsible urban development.

When Heat Becomes an Existential Threat

Climate impacts are often described in terms of average temperatures, precipitation patterns, and statistical risks. For those affected, they are very concrete. A very old, mildly dementia-affected woman lives with her husband in their own home. Until a heat wave sets in, both manage their daily lives independently. During the persistent heat, however, the woman repeatedly forgets to drink. She rejects her husband's reminders because she believes she has only just had something to drink.

With each hot day she becomes more confused and physically weaker. After a week, her husband realizes that he can no longer ensure care at home. A nursing home becomes necessary. The placement protects the woman but separates the couple and places an additional burden on the family. After a lengthy search, a place is found 30 kilometers away. There is no air conditioning there; regular fluid intake and nursing care can, however, be ensured.

The case illustrates the social dimension of climate adaptation. Heat affects people differently. Those especially at risk are the elderly, the chronically ill, small children, and people in poorly insulated or severely overheated apartments. Nursing homes, hospitals, daycare centers, and social services must therefore be systematically incorporated into municipal climate-adaptation and heat-protection plans.

Health Consequences of the Hot Summer

The Deutscher Wetterdienst classified the summer of 2026, with an expected mean temperature of 19.6 degrees Celsius, as one of the warmest since records began. Across Germany, around 22 hot days of at least 30 degrees and about five very hot days of at least 35 degrees were recorded. Particularly exceptional was the heat wave from June 18 to 28 (1).

The Robert Koch-Institut estimated roughly 16,300 heat-related deaths for 2026 (2). Such RKI figures are based on statistical models, because heat rarely appears on death certificates as the immediate cause of death and usually acts in combination with preexisting conditions. The uncertainty of the estimate does not diminish its health-policy significance. According to the epidemiologist Alexandra Schneider, cited by Deutsche Welle, the absence of a marked drop in mortality following the heat waves argues against the assumption that those affected would have died only a few days or weeks later anyway (3).

The Hot Summer as a Municipal Wake-Up Call

High temperatures and drought across Germany, wildfires in the Eifel region, and the low water levels of the Rhine show that climate risks remain confined neither to individual regions nor to individual sectors. For cities and municipalities, two closely connected tasks arise.

First, they must contribute to climate mitigation. Well-insulated buildings require less energy; municipal heat supply and public transport must be switched to climate-friendly technologies, and renewable energy must be expanded. Second, municipalities must cope with the consequences of climate change that can no longer be fully avoided today. Adaptation to climate change includes the precautionary handling of heat, heavy rainfall, flooding, drought, and water scarcity, as well as dealing with the rising burdens on social infrastructure.

The Legal Framework in Europe and Germany

The legal framework in Europe and Germany builds on international agreements such as the Paris Agreement of 2015 (4). In Germany, the Bundes-Klimaschutzgesetz sets the goal of climate neutrality by 2045 in Section 3 (5). It obligates above all sectors such as energy, industry, buildings, and transport to reduce emissions. Sector-specific laws, including the Wärmeplanungsgesetz, provide instruments for implementation. Federal law does not, however, contain a general obligation for municipalities to draw up climate-mitigation plans.

The Bundes-Klimaanpassungsgesetz obligates the bodies responsible for public tasks to take adaptation into account in a cross-sectoral and integrated manner (6). Among the items named are heavy rainfall, flooding, drought, low water levels, and urban heat islands. Under Section 12, the Länder must provide that municipal adaptation plans are drawn up. In doing so, existing foundations such as heat action plans, hazard maps, and open-space concepts are to be taken into account.

There is, however, an asymmetric framework: the Bundes-Klimaschutzgesetz does obligate individual sectors to engage in climate mitigation. Individual municipalities, however, are precisely not obligated to take measures at their level to reduce greenhouse gas emissions. Funding guidelines merely describe what effective climate mitigation at the local level could look like. The Bundes-Klimaanpassungsgesetz goes somewhat further, in that it at least requires climate-adaptation plans. Relevant foundations such as heat action plans, hazard maps, and open-space concepts are to be taken into account. The law does not, however, obligate municipalities to also take implementation measures such as, in our case, precautionary measures to protect old and sick people from the heat. This restraint on the part of the federal government in reaching directly into the municipal level with requirements has fiscal reasons. Under the connexity principle of Article 104a of the Basic Law, whoever orders something must also pay for it. The consequence of this restraint, however, is: climate mitigation and climate adaptation are not a mandatory municipal task.

Between Legal Requirements and Municipal Reality

Germany has numerous climate-policy rules. The central problem lies less in a lack of goals than in their lack of bindingness, funding, and practical feasibility. Municipalities must simultaneously renovate schools, maintain roads, build daycare centers, enable housing, and finance social services. Climate mitigation and adaptation, by contrast, often demand investments whose benefits become visible only in the medium or long term.

Financially weak cities are thereby placed at a structural disadvantage. A new school or road generates an immediately recognizable benefit. An unsealed area that prevents heavy-rainfall damage in ten years is politically harder to convey. Prevention is successful when damage fails to occur. It is precisely this success that is barely visible in everyday life.

Governance Among the Federal Government, the Länder, and Municipalities

Municipal heat planning cannot replace national energy policy. A city cannot meet its electricity needs independently of supra-regional grids. It can develop a heat action plan, but it cannot alone guarantee the financing of the health care system. For this reason, the tasks of the European Union, the federal government, the Länder, and the municipalities, as well as the contributions of business and private households, must be more clearly delineated from one another.

Funding programs from the EU, the federal government, and the Länder support individual projects. They do not, however, replace reliable base funding. The application process alone ties up staff, requires expertise, and causes high transaction costs. Small or over-indebted municipalities are therefore often less able to make use of available funding opportunities than cities with strong staffing and finances (7).

Five preconditions are necessary for viable governance:

• clear statutory responsibilities and a coordinated framework of tasks,
• multi-year and adequate funding commitments,
• sufficient technical and planning capacities within the administrations,
• simpler funding and permitting procedures, and
• measurable goals with regular public monitoring.

Classifying climate mitigation and climate adaptation as a voluntary or mandatory municipal task is therefore not a purely legal question. It determines whether measures are continued or cut first when the budget situation is tight.

Berlin Relies on Integrated Urban Development

Berlin has committed to becoming climate-neutral by 2045 at the latest. The Berliner Klimaschutz- und Energiewendegesetz of 2016 contains interim targets for reducing CO₂ emissions in Section 3 (8). The Berlin Energy and Climate Protection Program of 2018 bundles the central measures; sectoral strategies complement it (9).

Heat and Buildings

The Berlin heat plan adopted in 2026 spells out the path to a climate-neutral heat supply by 2045 (10). It connects the reduction of heat consumption with the expansion of renewable energy and the use of waste heat. Heat planning is especially relevant because buildings and heat supply have long investment cycles. Wrong decisions have effects over decades.

Spatial Planning and Climate Adaptation

The Urban Development Plan Climate 2.0 connects climate mitigation and adaptation with spatial development (11). It takes into account green and open spaces, water, heavy rainfall, flood protection, and the question of where structural development is compatible with climate goals. The Berlin climate-adaptation act, in force since November 2025, additionally obligates the Land to adopt a precautionary adaptation strategy and an adaptation program on the basis of a climate risk analysis (12).

Heat Action Plan

Since 2025, Berlin has additionally had a heat action plan (13). It takes up the recommendations of a federal–Länder ad hoc working group, "Health-Related Adaptation to the Consequences of Climate Change," from 2017, with eight core measures (14), and combines a public information campaign with measures such as the greening and shading of squares and buildings. The heat action plan serves both coordinated prevention and the improved management of acute heat phases.

Strengths and Limits

The strength of the Berlin model lies in its systematic approach. Climate mitigation and adaptation to climate change, energy, buildings, heat, transport, open space, water, heat exposure, and urban development are not treated separately. This reduces the risk that a measure in one policy field exacerbates problems in another. For example, densification can create additional housing while at the same time impairing green spaces and nighttime cooling.

The integration does, however, increase the need for coordination. Many administrations, state-owned enterprises, boroughs, and private actors must be involved. Planning effort and conflicting goals can slow decisions. Berlin's challenge therefore consists in translating the technical breadth into a manageable number of funded and time-bound measures.

London Combines High Ambitions with Sectoral Priorities

The London Environment Strategy of 2018 initially aimed at a CO₂-neutral city by 2050. The mayor later brought the target forward significantly: London is to reach Net Zero by 2030 (15). The strategy concentrates on energy efficiency and building renovation, low-emission public transport, clean energy, less motorized private transport, as well as greening and quality of life.

Climate Mitigation in the London Plan

The London Plan 2021 anchors climate mitigation in spatial development (16). Larger new-build projects are to be oriented toward net-zero operation. In 2025, the City of London published a complementary resilience strategy with climate dimensions (17). The planning follows an energy hierarchy: first avoid energy demand, then ensure an efficient and clean supply, and finally use renewable energy on site.

The city, however, has only limited control over its energy system. About 95 percent of the energy consumed in London is drawn from outside the Greater London area. Achieving the city's goals therefore also depends on national energy policy, power grids, regulation, and private investment. Ambitious goals at the city level cannot replace higher-level decisions.

Heat Ready London

With Heat Ready London, the city presented in 2026, for the first time, a city-wide strategic approach to adapting to increasing heat (18). The initiative connects health protection, urban planning, buildings, and infrastructure with social questions. At its center are people in overheated apartments, neighborhoods with little greenery, and groups with elevated health risks.

London thus treats heat not solely as a health problem but as a risk to the economic and social functioning of the metropolis. A study published in the context of the initiative estimates that the annual costs of climate change for London could reach up to 36 billion pounds without additional measures. Such estimates are associated with uncertainties, but they make visible the possible order of magnitude of forgone prevention.

Strengths and Limits

London's strength lies in concentrating political attention on priority fields of action. The limit lies in its constrained competencies and in its dependence on external energy systems. A narrow focus eases implementation but can overlook interactions when no overarching spatial and social analysis is carried out.

Berlin and London Compared

The comparison shows no royal road. Berlin stands for the strength of an integrated approach. The city captures interactions among energy, mobility, building planning, water, heat, and social infrastructure. London stands for consistent prioritization. An ambitious goal and clearly named sectors can bundle political attention, resources, and accountability.

Both models carry risks. An exclusively integrated approach can become complex and slow. An exclusively focused approach can overlook important dependencies. German municipalities should therefore not choose between breadth and priority. They need both: an overall analysis of the system and a limited number of implementation-ready projects.

Shared Findings

• Climate goals take effect only when responsibilities, budgets, and timelines are defined.
• Climate adaptation must take health-related and social vulnerability into account.
• Municipal strategies remain dependent on national energy, transport, and financial systems.
• Monitoring must capture emissions reduction and adaptation progress separately, but in a coordinated way.

What German Municipalities Can Learn from This

First, Capture the Entire System

At the outset there should be an emissions inventory and a climate risk analysis. Every municipality must clarify where its most important greenhouse gas emissions arise, which neighborhoods and population groups are especially at risk, which infrastructures are critical, and where dependencies on higher-level grids or decisions exist. Equally important is the temporal perspective: some measures can be implemented in the short term, others require years of planning.

Then Set Clear Priorities

A comprehensive strategy must not lead to everything being started at once. Municipalities should select a few fields of action in which responsibility, funding, and political backing have been clarified. Suitable examples include municipal buildings, heat networks, safe cycling and walking paths, unsealing, urban greenery, heat protection in care facilities, and stormwater management.

Visible projects fulfill several functions. They reduce concrete risks, build knowledge within the administration, and show the public that the strategy is being implemented. After an evaluation, successful procedures can be transferred to further neighborhoods or facilities.

Combine Mitigation and Adaptation

Multifunctional measures are especially valuable when human and financial resources are limited. Energy-efficient renovations reduce energy consumption and can at the same time improve summer heat protection. Trees and green spaces cool neighborhoods, promote biodiversity, and increase quality of stay. Unsealing and sponge-city measures reduce heavy-rainfall risks and retain water for dry periods.

Account for Social Vulnerability

Planning must not orient itself solely toward technical risks. People with low incomes, health impairments, a lack of support, or unsuitable housing are less able to protect themselves. Municipalities should therefore combine heat and heavy-rainfall maps with social and health data. Investments are to be prioritized where high exposure and low capacity for self-adaptation coincide.

Without Funding, Climate Policy Remains a Concept

Climate mitigation and adaptation require investments in buildings, energy and heat networks, transport, green spaces, water infrastructure, health protection, and staff. Funding programs can enable pilot projects, but they are often time-limited and tied to burdensome procedures. For permanent tasks, municipalities need reliable base funding and multi-year commitments.

Long-term prevention competes politically with short-term, visible spending. In its climate ruling of 2021, the Federal Constitutional Court emphasized the importance of intertemporal freedom and intergenerational fairness (19). From this it also follows for municipal decisions: long-term risks must not be deferred solely because acute problems are politically more visible.

Make Success Measurable

Greenhouse gas emissions can be monitored comparatively well through standardized inventories and quantitative indicators, even if methodological uncertainties remain. For adaptation, measurement is more difficult, because successes often consist of avoided damage, illness, or deaths. Nevertheless, municipalities can define verifiable qualitative indicators here as well. Quantitative and qualitative indicators can include:

• the share of renovated municipal buildings and the energy consumption avoided,
• the expansion of renewable heat and the progress of heat planning,
• unsealed area and accessible green spaces in burdened neighborhoods,
• the number of facilities with a binding heat-protection plan,
• implemented heavy-rainfall and flood-prevention measures, and
• budget disbursement, project progress, and adherence to timelines.

Five Recommendations for Practice

1. Plan in an integrated way: address climate mitigation and adaptation together with urban development, energy, transport, health, water, heat, and social questions.
2. Prioritize in a binding way: select a few projects and define timeline, responsibility, budget, and target magnitude.
3. Orient socially: consider vulnerable people, facilities, and neighborhoods first in heat protection and investments.
4. Secure implementation: combine legal requirements with funding, skilled staff, and simplified procedures.
5. Publish impact: evaluate progress regularly and adjust measures when goals are missed.

Climate Policy as a Permanent Municipal Task

The hot summer of 2026 should not be treated as an exceptional one-off event. It shows how the tasks of municipalities are changing. Cities must continue to provide housing, schools, roads, and energy supply. At the same time, they must keep these systems functioning under changed climatic conditions.

Investments in heat protection, green spaces, water infrastructure, energy-efficient buildings, renewable heat, and resilient transport can limit future damage. They protect physical assets, health, and economic performance. The social dimension remains central: those who have income, suitable housing, and support can protect themselves more easily. The old woman mentioned at the beginning is doing well again by now, even though she now lives in a home rather than at home. Other people depend on public prevention.

From Berlin and London a workable sequence emerges: plan broadly, begin in a focused way, measure results, and scale up successful measures. Berlin shows how interactions can be captured systematically. London shows how ambitious goals and priorities can bundle the capacity to implement. Together, both approaches form the basis of a learning municipal transformation process.

Waiting does not lower the costs. It shifts them into the future and increases health-related, economic, and political risks. The decisive task therefore consists in treating climate mitigation and adaptation not as add-on projects but as an integral part of municipal public services of general interest (Daseinsvorsorge) and urban development.

Sources

1. Deutscher Wetterdienst: Deutschlandwetter im Sommer 2026, press release of August 31, 2026 (dwd.de).
2. an der Heiden, M. et al.: Wochenbericht zur hitzebedingten Mortalität, week 36/2026, Robert Koch-Institut, DOI 10.25646/14440.
3. Vergin, J.: Sommer 2026 mit historischem Höchststand an Hitzetoten, Deutsche Welle, September 16, 2026 (dw.com).
4. Paris Agreement (consilium.europa.eu); on the international agreements and European climate legislation, see Schlacke, S./Wagner, J., Handbuch Klimarecht, Beck 2026, chs. 1 and 2.
5. Bundes-Klimaschutzgesetz of December 12, 2019 (BGBl. I p. 2513), amended by Article 1 of the Act of July 15, 2024 (BGBl. 2024 I No. 235).
6. Bundes-Klimaanpassungsgesetz of December 20, 2023 (BGBl. 2023 I No. 393).
7. Schlacke, S./Wagner, J., Handbuch Klimarecht, Beck 2026, ch. 13.
8. Berliner Klimaschutz- und Energiewendegesetz of March 22, 2016.
9. Berliner Energie- und Klimaschutzprogramm 2030 (berlin.de).
10. Berliner Wärmeplan (berlin.de).
11. Berliner Stadtentwicklungsplan Klima 2.0 (berlin.de).
12. Berliner Klimaanpassungsgesetz of November 7, 2025.
13. Hitzeaktionsplan für das Land Berlin (berlin.de).
14. Handlungsempfehlungen für die Erstellung von Hitzeaktionsplänen (bundesumweltministerium.de).
15. London Net Zero 2030: An Updated Pathway (zerocarbonaccelerator.london) London Environment Strategy.
16. The London Plan 2021 (london.gov.uk).
17. London Resilience Strategy (london.gov.uk).
18. Heat Ready London (london.gov.uk).
19. Federal Constitutional Court, order of March 24, 2021 (bundesverfassungsgericht.de).

This article was developed with the support of artificial intelligence.