ECOLOGICAL FOUNDATIONS, CLIMATE CRISIS, AND ENVIRONMENTAL JUSTICE
Vienna has consistently ranked among the world’s most liveable cities over the past two decades (Stadt Wien, 2026). This reputation is commonly attributed to the city’s combination of affordable housing, high-quality public services, efficient public transport, extensive green space and comparatively favourable environmental conditions (Khomenko et al., 2020; Friesenecker, Riederer & Cucca, 2022). These qualities reflect a long tradition of public planning and investment that conceived environmental quality as an integral component of urban welfare. As Mocca et al. (2020) show, this planning approach became visible in successive strategies that combined compact urban development with investments in public transport, the protection of the Vienna Woods and Green Belt, urban renewal programmes, and environmental infrastructure such as flood protection and high-quality drinking water provision. Reflecting broader international climate agendas, Vienna has progressively integrated climate mitigation into urban policy since the 1990s, making it a cross-cutting objective that shapes transport, housing, land-use and infrastructure planning. Its mitigation strategy centres on expanding public transport and cycling infrastructure, maintaining compact urban development and decarbonising the existing building stock (Mocca et al., 2020).
Climate Change and the Rise of Adaptation
While mitigation became increasingly embedded within Vienna’s urban development agenda, growing impacts of climate change elevated adaptation to a second pillar of climate policy. Among these impacts, urban heat has emerged as the city’s most pressing environmental health challenge. Owing to its location in the Pannonian Basin, Vienna has experienced warming substantially above the global average, while the frequency and duration of heatwaves have increased markedly over recent decades (Orlik et al., 2025). The year 2024 was the warmest on record, with record numbers of hot days and tropical nights, while extreme rainfall in September caused severe flooding across parts of the city. Climate simulations have identified the densely built inner districts as Vienna’s principal urban heat islands (Žuvela-Aloise et al., 2025), whereas the Vienna Woods in the western part of the city, the Danube corridor and larger green spaces provide important cooling functions as highlighted in Figure 5. In response to these developments, climate adaptation has become an increasingly important second pillar of Vienna’s climate policy since the adoption of the Urban Heat Island Strategy in 2015, placing greater emphasis on urban greening, heat mitigation and resilience to drought and heavy rainfall (Friesenecker et al., 2024). As mitigation and adaptation intersect more closely with housing, mobility and land-use planning, their implementation requires addressing unequal vulnerabilities while navigating new trade-offs across the city.
Figure 5: Land Use in Vienna
Vienna’s contemporary adaptation strategy builds on a long tradition of protecting and expanding urban green infrastructure. Since the early twentieth century, planning policies have safeguarded large ecological assets at the urban fringe, including the Vienna Woods, the Green Belt, and later the Danube Island, thereby preserving extensive cooling corridors and recreational landscapes despite sustained urban growth (Breiling, 2008; Brenner, Friesenecker & Mocca, 2021; Žuvela-Aloise et al., 2025). More recently, ecological objectives have increasingly been integrated into urban expansion areas through planning guidelines requiring the provision of public green space, climate-sensitive open-space design and the principle that residents should have access to high-quality public green space within approximately 250 metres of their homes (Brenner, Friesenecker & Mocca, 2021). Despite these long-standing planning traditions, cooling capacities remain unevenly distributed across the city. Dense inner-city neighbourhoods, characterised by sealed surfaces and limited vegetation, generally offer fewer cooling opportunities than the greener urban fringe (Friesenecker et al. 2025; Gabor et al. 2026), while the quantity and quality of accessible green space also vary between neighbourhoods (Zoderer et al. 2024). Consequently, climate adaptation has increasingly shifted towards smaller-scale interventions within the existing urban fabric, including street trees, de-sealing, green roofs and façades, shaded public spaces, cooling zones and traffic-calmed neighbourhoods.
Emerging Climate Risks, Inequalities and Trade-offs
Unequal cooling capacities become socially significant climate risks only where they intersect with social vulnerability. Spatial analyses show that the highest heat risks emerge not simply in the hottest parts of the city, but where elevated temperatures coincide with concentrations of socially vulnerable populations. In Vienna, these intersections occur particularly in densely built working-class neighbourhoods characterised by limited green infrastructure, extensive surface sealing and higher shares of low-income and migrant populations, whereas affluent inner-city neighbourhoods may experience similarly high temperatures but generally possess greater adaptive capacities (Friesenecker et al., 2025). More broadly, environmental inequalities in Vienna cannot be reduced to a simple divide between affluent and disadvantaged neighbourhoods. Different population groups experience distinct constellations of urban heat, air pollution, traffic noise and access to green space, while migrants and lower-income households generally face poorer environmental conditions and lower access to urban vegetation (Khomenko et al., 2020; Friesenecker, Riederer & Cucca, 2022; Neier, 2023). Building on this, Gabor et al. (2026) show that climate vulnerability is inherently intersectional, as socio-economic disadvantage, migration background, age, gender and care responsibilities frequently overlap and reinforce one another. Finally, Seebauer et al. (2024) demonstrate that objectively measured neighbourhood temperatures correspond only weakly with residents’ experienced heat stress, highlighting that housing quality, building characteristics and adaptive capacity are as important as neighbourhood conditions in shaping experienced heat stress.
The growing prominence of climate adaptation has also made the governance of urban space increasingly contested. In densely built neighbourhoods, where the need for cooling measures is greatest, opportunities for additional greening are constrained by competing land uses and existing infrastructure. Measures such as street greening, tree planting, superblocks and traffic calming require the reallocation of scarce street space, bringing competing visions of urban mobility, public space and environmental quality into direct conflict (Brenner et al., 2024). Against this backdrop, recent research has increasingly argued that adaptation measures should be prioritised where the greatest reductions in climate risk can be achieved by simultaneously considering heat exposure, social vulnerability and the cooling potential of interventions (Friesenecker et al., 2025). Such redistributive approaches also appear to enjoy broad public legitimacy. Residents express widespread support for greening measures across the city, including investments targeted at less-green neighbourhoods and areas they rarely visit, suggesting that prioritising climate adaptation according to need commands substantial public backing despite socio-economic differences (Schneider et al., 2025). Vienna has further sought to strengthen the legitimacy of climate action through greater civic engagement in adaptation, including participatory planning formats, resident-led greening initiatives and increasing recognition of local social capital as an important resource for urban resilience (Ahn et al., 2023; Muhr et al., 2026).
Emerging Trade-Offs
At the same time, nature-based solutions may produce unintended social consequences if improvements in environmental quality are accompanied by rising property values and displacement pressures. Although Vienna’s extensive social housing sector moderates these dynamics compared with many other European cities, research points to persistent policy silos between climate adaptation and housing policy, particularly within the deregulated private rental sector, where risks of green gentrification remain most pronounced (Friesenecker et al., 2024; Dorner et al., 2026). Ultimately, the challenge for Vienna is no longer simply to implement effective climate measures, but to reconcile climate resilience with continued population growth, affordable, high-quality housing provision and social inclusion.