Hamburg Climate Futures Outlook 2024
Hamburg Climate Futures Outlook 2024
Photo: CLICCS, Universität Hamburg
The Hamburg Climate Futures Outlook 2024 provides a unique systematic and global assessment of the context conditions for sustainable climate change adaptation, evaluating the social dynamics of deep decarbonization and the physical dynamics in regional climate variability and extremes. Through nine case studies across the globe, the assessment provides insights into key barriers and opportunities for sustainable climate change adaptation.
Key FindingsKey Findings in a nutshell
Reaching net-zero CO2 emissions by 2050 is currently not plausible. Especially corporate responses, consumption trends, and the lack of effective fossil-fuel divestment inhibit deep decarbonization.
Many social drivers support decarbonization, but lack a decisive turning point.
Long-term climate change and internal climate variability together can lead to ecosystem and socioeconomic disruptions with potentially devastating consequences.
Sustainable and climate change adaptation is urgent. But so far, coping and incremental responses predominate.
A more inclusive and connected repertoire of climate action is needed:
- Work across sectors and scales to improve preparedness for the impacts of climate change.
- Integrate diverse knowledges for just climate action.
- Use political, legal, and financial pressure to phase out fossil fuels.
More information
Figures
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Climate change adaptation assessment ...in the investigated urban, rural and coastal areas. Download figure as jpeg file (2MB)
Figure 5.11: Climate change adaptation assessment (please read in clockwise direction and from the center to the periphery) in urban (dark grey), rural (green) and coastal areas (blue) investigated in this chapter. They are divided into the sections of coping, incremental, and transformative. The hatched areas indicate a tendency toward but not fully achieved state, while blanks indicate that such processes were not revealed at all by the analyses in this chapter. Colored areas indicate that, for example, the process of coping is prevalent and well-established
Case study locations and climate change effects. Download figure as jpeg file (200 kb)
Schematic of the MPI-GE (Grand Ensemble). Ensemble runs of 30 simulations for the period 1850-2014 represent five future climate scenarios. Download figure as jpeg file (200 KB)
Figure 4.1: Initial conditions (year 1850) for the 30 simulations are chosen from a pre-industrial control simulation and represent different conceivable climates for that year. The ensemble of 30 simulations for the historical period (1850-2014) span the possibility space of climate while considering internal variability (blue shading). The ensemble mean (blue line) estimates the forced response during that period. Five future scenarios (SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5) exist for all 30 ensemble members, covering the response of the climate system (red and purple lines), including uncertainty arising from internal variability (red-purple shadings). A single ensemble member is taken as an example (black line), starting from its own initial conditions in 1850 (1), which can be followed through the historical period (2) into five different futures, depending on the emission scenario (3-7). At different points in time, all ensemble members have their own climate state that represents a combination of forced response and internal variability. This is exemplified with the global temperature patterns from the first ensemble member shown at different points in time (global maps 1-7). The global maps 3-7 show the warming patterns in year 2100
Climate actions ...mentioned or demanded in media reporting on climate futures across German, Indian, South African, and US media. Download figure as jpeg file (50 KB)
Figure 3.4: Climate actions: mentioned or demanded in media reporting on climate futures across German, Indian, South African, and US media (n=734); data is retrieved from quality print media, regional print media, tabloid media, digital news media, and weekly news magazines
Case Studies Summary
Nine case studies:
- Hamburg, Germany
- São Paulo, Brazil
- Ho Chi Minh City, Vietnam
- Rural Areas of Northeast Lower Saxony, Germany
- Rural Communities in Nepalese Highlands, Nepal
- Pastoralists in Kunene, Namibia
- Coastal Adaptation in North Frisia, Germany
- Small Islands Adaptation in the Maldives
- Coastal Adaptation in Taiwan
Full case studies can be found in chapter 5 (page 96-138)
Hamburg, Germany
The Free and Hanseatic City of Hamburg is the second largest city in Germany and is marked by its large port and its direct connection to the North Sea via the river Elbe. Hamburg faces significant climate-related risks, including storm surges, riverine flooding, and pluvial flooding, all worsened by climate change. These risks stem from rising sea levels and the resulting groundwater rise (leading to groundwater flooding), severe storm surges causing coastal floods, and heavy, prolonged rainfall triggering river flooding. The growing occurrence of high-intensity rainfall events and the risk of pluvial flooding are worsened by the increased sealing of urban surfaces due to expanding construction activities.
The city’s main adaptation strategies involve flood protection infrastructure, such as dikes, storm surge barriers, and adaptive urban planning. Hamburg has also invested in nature-based solutions like restoring wetlands, created green spaces to absorb excess water, and a green roof strategy. These responses have been successful in protecting the city from severe flooding, but challenges remain. Rising sea levels and increasing rainfall intensity are testing the limits of the existing infrastructure, requiring continued investment and innovation to keep pace with the evolving climate risks. Overall, Hamburg’s adaptation measures have been effective, but the city needs to explore synergies between climate adaptation and mitigation, such as balancing housing densification with green infrastructure goals. Sustainable climate change adaptation requires comprehensive risk assessments and governance instruments promoting transformative adaptation measures.
São Paulo, Brazil
São Paulo is the largest city and urban economy in Brazil and Latin America. It is marked by accelerated industrialization, aggressive urban expansion and high social inequalities. The city faces major climate-related risks, including floods, droughts, and heatwaves. These challenges are exacerbated by ongoing climate change, environmental degradation, and significant socio-economic inequalities. Climate change is expected to aggravate environmental and urban problems and increase risks, especially for communities already living in vulnerable conditions. The city must respond to expected changes in the distribution, intensity, and frequency of risks related to extreme whether events.
São Paulo has engaged with international climate networks and introduced policies aiming at emission reductions, improved urban infrastructure, and water management. However, implementation of climate adaptation measures is lagging far behind due to political instability and economic interests that prioritize short-term gains over long-term resilience. High social inequalities and the lack of political support to climate action also constrain sustainable climate change adaptation in the city. Despite being a pioneer in terms of climate action in Brazil and internationally, the adaptation measures observed thus far primarily focus on planning and networking, and the climate adaptation goals and specific actions established so far are vague and inadequate. For effective and sustainable climate adaptation, São Paulo needs to address these political and social challenges, improve infrastructure, and ensure more equitable climate resilience across its diverse population.
Ho Chi Minh City, Vietnam
Ho Chi Minh City, Vietnam’s largest metropolis, is one of the world’s most vulnerable cities to climate change impacts. The city faces severe climate-related risks, including urban flooding exacerbated by extreme rainfall, land submersion, and rising temperatures due to climate change. The city’s main adaptation strategies focus on structural measures like dikes, flood gates, and pumping stations, alongside nature-based solutions such as the Phu Xuan wetland park, which helps to absorb excess water and reduce heat stress. While these responses have had some success, significant challenges remain. The city’s reliance on hard infrastructure is constrained by limited funding, a lack of measurable targets, and insufficient public engagement. Additionally, rapid urbanization and inadequate drainage systems continue to exacerbate flooding risks, particularly in low-lying areas. The authoritarian political environment further limits the adoption of more participatory and transformative approaches necessary for long-term resilience.
Overall, Ho Chi Minh City’s adaptation measures have been partially effective, but they require continuous upgrading and a shift towards more integrated, sustainable planning to keep pace with evolving climate risks. Successful sustainable climate change adaptation requires more integrated planning as part of a wider process-orientated transformative adaptation. A stronger involvement of the urban citizens beyond mere awareness raising is regarded as essential to enhance private engagement and to close implementation gaps.
Rural Areas of Northeast Lower Saxony, Germany
Northeastern Lower Saxony, Germany, faces significant climate-related risks, primarily from increased droughts, storms, and pests that have an impact on agriculture and forests. The region’s adaptation strategies include irrigation systems for crops and adjustments in planting and harvesting schedules. Investments in soil fertility, water storage, and drought-resistant crops are adaptation options in the region. Transformative adaptation consists of fundamental changes to the farming system, such as the adoption of organic farming. Forest management focuses on reducing human intervention to allow natural recovery and implementing adaptive measures like planting climate-resilient tree species, also considering the role of forests as carbon sinks.
These strategies have had mixed success. While irrigation and crop adjustments offer short-term relief, more sustainable solutions, like investing in drought-resistant crops or in organic farming, face economic and practical hurdles. Forest adaptation efforts are constrained by the uncertainty of future climate conditions and high costs of new management practices. Challenges such as frequent regulatory changes, lack of trust in politics, adequate financial incentives, and the public image of farming’s negative environmental impact persists. Continued adaptation efforts and policy alignment are necessary to address these evolving climate risks effectively.
Rural Communities in Nepalese Highlands, Nepal
Nepal’s rural regions, with its extreme altitude variations and fragile ecosystems, are highly vulnerable to climate change impacts. Droughts, glacier melt, floods, and heat waves, with extensive effects on the regional hydrological cycles, bear a considerable threat to the well-being of the mountain dwellers and downstream communities. Recent studies indicate that Nepal is among the most affected nations by extreme weather events, with significant elevation-dependent warming expected to intensify future climate risks.
Local communities in Nepal possess a strong awareness and understanding of climate change which complements scarce observational data. Both provide guidance to design appropriate proactive and reactive adaptation measures tailored to the local contexts. Locally induced adaptation measures relate to agricultural diversification, disaster risk management, and community-based initiatives including changing crops, partial drainage of glacial lakes, and community-based seed banks. The Community Adaptation Plan of Action, developed with local input, supports these efforts by identifying and implementing strategies to mitigate climate impacts. Despite these efforts, adaptation challenges remain, including gaps in policy coherence, the lack of adequate and predictable financial and technological support, and the need for better integration of community-level initiatives and local government efforts.
Pastoralists in Kunene, Namibia
In Kunene, Namibia, the key climate-related impacts include extreme droughts, heat waves, and changing rainfall patterns that have an impact on vegetation growth and livestock farming. The projected expansion of arid regions puts pressure on the already vulnerable agricultural systems, affecting food security and the livelihoods of rural communities such as pastoralists. Thus, adaptation strategies in Kunene primarily involve migration and economic diversification, aimed at coping with these adverse conditions. Migration helps pastoralists seek better grazing areas, though it often leads to conflicts over land rights. Diversification attempts, such as communal gardens and fish farming, have been largely unsuccessful in the long run due to economic constraints and conflicts within communities.
In rural areas of Namibia such as Kunene, people are constrained to adapt to climate change on the household level because they lack infrastructure and capital. While the state and NGOs encourage and try to enable some adaptation measures, these are often based on assumptions that contradict local norms and values, making it not plausible that they will become a long-term adaptive strategy. However, while livelihoods have indeed worsened due to global warming, most people in such marginalized economic and political environments experience plenty of ups and downs in their lives regardless of climate change.
Coastal Adaptation in North Frisia, Germany
North Frisia, Germany, faces considerable climate-related risks, including rising sea levels, increased storm surge intensity, and changing precipitation patterns. The region's adaptation strategies have been historically focused on reinforcing traditional diking systems and only more recently on integrating nature-based solutions. The North Frisian governmental coastal protection plan involves regular assessments and upgrades of dikes to address the risks associated with sea-level rise and storm surges. In addition to dike reinforcement, the Strategy Wadden Sea 2100 promotes human-induced but naturally driven sediment relocation, to enhance coastal resilience. The strategy is also an initial attempt to bring together citizens, administrative staff, and scientists.
These adaptation measures have been effective in maintaining coastal protection and also aim at integrating ecological concerns. However, challenges persist, particularly in balancing traditional diking with new nature-based approaches. There is a need for continued innovation and collaboration to address evolving climate risks. Although diking remains a reliable and socially accepted adaptation strategy, due to current and anticipated impacts of climate change, innovative approaches that allow communities, administration, and policy to explore and test new methods of coastal protection are crucial.
Small Islands Adaptation in the Maldives
The Maldives is highly vulnerable to climate-related impacts due to its low elevation and dependence on fragile coral reefs. The primary risks include sea level rise, coastal erosion, and coral bleaching, which threaten the atolls and their ecosystems. In response, the Maldives has implemented various adaptation measures such as constructing sea walls and reclaiming land in creating elevated islands like Hulhumalé. These efforts aim to mitigate the immediate risks posed by rising sea levels and coastal erosion.
However, the effectiveness of these adaptation strategies has been evaluated differently. While some measures have provided relief, others have led to unintended consequences, such as exacerbated erosion and ecological damage. Poor implementation and maladaptive practices, including reef modifications, have sometimes worsened the situation. Additionally, conflicting or contradictory political interests at international, national and local levels impede the consistent application of protective measures across the islands.
Overall, the Maldives has made notable efforts to address climate risks, but challenges remain. Relying solely on standard hard protection methods harms sustainability and biodiversity. Bearing in mind that Maldivian atolls can expand despite sea level rise, healthy coral reefs remain essential for coastal protection. However, existing maladaptation increases unsustainable development and endangers the habitability of the islands.
Coastal Adaptation in Taiwan
Taiwan’s coastal areas are exposed to substantial climate-related risks, including typhoons, extreme rainfall, storm surges, and rapid sea level rise. The island’s adaptation strategies primarily involve constructing hard infrastructure, such as seawalls and coastal barriers, alongside soft measures like beach nourishment. Additionally, Taiwan has developed comprehensive plans through its Coastal Zone Management Act and Climate Change Response Act, which include enhancing coastal protection, preserving marine resources, and improving early warning systems.
These strategies have yielded some success in mitigating coastal hazards and managing extreme weather impacts. However, challenges persist due to fragmented administration, a focus on existing sectoral plans, and limited public engagement. Increasing sea levels and intensified typhoons continue to strain current infrastructure, requiring ongoing adaptation efforts and integration of broader, more flexible strategies to address evolving climate risks.
Taiwan’s frequent experiences with extreme events have generally heightened disaster risk perception, with safety playing a crucial role in social awareness of the coasts. Although climate change adaptation in Taiwan is mainly adopted from existing sectoral plans and strategies, the experiences gained from disaster preparedness and emergency response provides opportunities to enhance climate risk perception. This enhancement can enable a socially improved adaptation to climate change in Taiwan by more effectively leveraging synergies.