Benefits of Urban Greening
Harnessing the Power of Plants
Scientific evidence demonstrates that plants and Nature-based Solutions are essential to addressing the climate challenges that Paris faces. Rising temperatures, longer and more frequent heatwaves, and widening temperature gaps with surrounding areas are transforming the city’s climate.
Météo-France described 2022 as “the summer of all records”, and by 2030, summers with temperatures comparable to the deadly 2003 heatwave will be considered normal in Paris. Beyond the immediate human toll, extreme heat disrupts ecosystems, damages infrastructure, and affects daily life, particularly in the most exposed areas such as top floors under zinc roofs, poorly ventilated street canyons, and densely populated neighbourhoods affected by air pollution.
Scientific data shows that biodiversity and vegetation significantly mitigate these impacts. The coolest parts of Paris are precisely its most vegetated (the Bois de Boulogne, the Bois de Vincennes, and Père Lachaise cemetery), illustrating the power of plants to regulate microclimates, store carbon, and enhance wellbeing.
Vegetation can reduce urban temperatures by 2.5 to 3°C on average, and tree canopy can lower them by up to 8°C during heatwaves. From fields and meadows to forests, rivers, wetlands, parks, and gardens, all ecosystems offer powerful responses to metropolitan challenges. They help mitigate climate change by storing carbon in soils and vegetation, cool the city during heatwaves, and capture excess stormwater during heavy rainfall.
Delivering Multiple Benefits
Paris harnesses the potential of plants and ecosystems to deliver multiple environmental, social, and health benefits. These are fully embedded in its urban planning and policy frameworks. The city aims to become a “sponge city” by restoring soil permeability across at least 55 per cent of its territory by 2050, as outlined in the ParisPluie (Paris Rain Plan) adopted in 2025. Vegetation cools the urban climate, mitigates flooding, filters pollutants, enhances mental wellbeing, and improves the city’s aesthetic and ecological quality.
Buildings are a major lever in this strategy. The regional biodiversity agency is leading the “Grooves” study (Green Roofs Verified Ecosystem Services) on 30 green roofs across the metropolitan area. Early results reveal their remarkable capacity to retain water, depending on the depth and composition of the substrate, and their ability to spontaneously host more than 268 species of plants and mosses, demonstrating how built surfaces can become biodiversity reservoirs even in dense environments.
This integrated approach is supported by a coherent set of policies actively implemented at city-scale (Climate Plan, Bioclimatic Local Urban Master Plan, Biodiversity Plan, Health and Environment Plan, Sustainable Food Plan, Rain Plan, and Tree Plan). It is further reinforced by strong political leadership committed to greening every possible space.
The City Council’s adoption of the Master Plan was an opportunity to strengthen regulatory measures supporting biodiversity. A major step forward is the inclusion of the Paris Green and Blue Infrastructure Scheme—known as Les Chemins de la nature—within the regulatory framework.
The City’s Bold and Innovative Vision
Paris’s vision is to reinvent its urban model by weaving biodiversity into the very fabric of the city. This initiative is bold because it rethinks public space management on a scale unseen since the19th century, retrofitting an historic and densely built metropolis into a garden city. It proposes a paradigm shift: nature is no longer treated as ornamental but as a structural element shaping how the city grows, functions, and adapts.
At the heart of this transformation is an innovative ecological management approach launched in the early 2000s. Paris became one of the first global capitals to eliminate chemical pesticides, achieving a complete ban in 2015. A suite of pioneering techniques underpins this shift. Differentiated management adapts maintenance to each site’s ecological context, allowing some areas to become wilder and richer in biodiversity. Eco-grazing reduces mechanical intervention while naturally fertilising soils.
Beyond public spaces, the city transforms its built environment into living infrastructure by turning roofs, façades, and courtyards into ecological surfaces. Together, these actions represent a bold and innovative model for 21st-century cities, one where biodiversity, climate resilience, and urban life are inseparably linked.
Partnerships and Collaboration
Paris’s biodiversity strategy is inherently collaborative, drawing on expertise from across disciplines and sectors to deliver systemic change. The city recognises that transforming urban ecosystems requires breaking down silos and integrating nature into all aspects of urban planning.
Close cooperation with the Water and Sanitation Department ensures that rainwater management is fully integrated into greening projects. Permeable soils, rain gardens, and green roofs contribute to the city’s “sponge city” vision. Collaboration with the Department of Streets and Mobility enables the redesign of public space to combine cycle lanes, pedestrian areas, and vegetated surfaces, creating multifunctional and resilient streetscapes.
Urban planners and architects work alongside ecologists to embed biodiversity objectives into the new Bioclimatic Local Urban Master Plan, while landscape designers and horticultural experts shape the transformation of roofs, courtyards, and façades into ecological habitats.
The initiative engages public health professionals, sociologists, and local associations to maximise social and health co-benefits, ensuring equitable access to green space and reinforcing the role of nature in public wellbeing. The City of Paris draws on significant technical expertise and has reorganised to ensure collaboration across departments and disciplines, guaranteeing that biodiversity considerations are embedded at every level of decision-making.
Addressing Urban Challenges
The Issue
Paris faces a major ecological and urban challenge: how to reintroduce nature into one of the densest cities in Europe. With 2.1 million inhabitants in just 105 km², Paris is far more compact than Berlin, for example. The German capital is nine times larger in area, with only a population of 3.7 million. This exceptional density puts intense pressure on land use, leaving little room for new green spaces and complicating the balance between housing, mobility, and nature.
The consequences of this imbalance are already visible. Over the past 20 years, the sparrow population in Paris has declined by 70 per cent, reflecting a broader collapse of urban ecosystems and the disappearance of essential ecosystem services such as pollination, air purification, and water regulation. Without decisive action, biodiversity loss will accelerate, undermining ecosystem resilience and worsening the city’s vulnerability to climate impacts such as heatwaves, flooding, and air pollution.
These threats directly affect human health and wellbeing. Neighbourhoods with little vegetation experience higher mortality during heatwaves, poorer air quality, and fewer opportunities for social interaction and mental restoration.
The city is responding with targeted actions such as “Sparrow Quarters”, developed with the Ligue pour la Protection des Oiseaux (Bird Protection League), which create favourable nesting sites and habitats. Residents are encouraged to participate by planting seed-bearing species on balconies, terraces, or courtyards, and installing and surveying nesting boxes through citizen science initiatives that support bird populations.
The Impact of the Issue
Paris is facing increasingly severe climate-related threats, with rising temperatures, longer and more frequent heatwaves, and a growing risk of extreme flooding.
The “Paris 50 Degrees” City Council fact-finding mission report highlights how these changes could profoundly affect daily life in the coming decades. Urban heat islands intensify heatwave impacts, creating major public health risks. They also drive up energy consumption through increased use of air conditioning, and worsen air pollution. A study covering the summers between 1990 and 2015 in Île-de-France found that urban characteristics contributing to heat islands are associated with a significantly higher risk of heat-related mortality.
Heatwaves can be deadly in many ways. Cardiovascular events are the leading cause of death, and high temperatures also trigger a range of health risks, both direct (such as heatstroke) and indirect (such as reduced physical activity and sleep disruption). During the 2022 heatwaves, excess mortality in the Paris region rose by 21 per cent, and emergency room visits surged during the three major heat peaks. Vulnerable groups (older adults, pregnant women, children, and homeless people) are disproportionately affected, but prolonged and repeated heat events also weaken healthy individuals.
Another growing threat is the risk of a centennial flood, potentially as devastating as the one in 1910. Expanding green spaces, restoring permeable soils, and planting trees are essential to reduce these risks. Vegetation mitigates heat islands, lowers temperatures, supports water infiltration, and strengthens urban resilience, making biodiversity central to creating a safer and healthier future for Paris.
Nature Positive Solutions
Implementation
Over the past five years, Paris has significantly strengthened its biodiversity policy, embedding nature into the very fabric of the city. The adoption of the Bioclimatic Local Urban Master Plan marks a major milestone, integrating ecological corridors (Chemins de la nature), expanding “Protected Green Spaces” by 90 hectares, and introducing new categories such as “Protected Trees” and “Protected Open Spaces” to be vegetated. Paris has set an ambitious goal of creating 300 hectares of new green spaces.
A central focus is the greening of buildings, transforming rooftops, façades, and courtyards into vital habitats for urban biodiversity. Since 2018, vegetated roofs and walls have expanded to 138 hectares, offering refuge for pollinators, birds, and soil microorganisms while improving insulation and stormwater retention. Projects like the James Baldwin Library, featuring 90 per cent native species, 700 m² of green roofs, and 65 per cent permeable soil, demonstrate how architecture can actively support biodiversity.
Thirteen hectares of green spaces have been created since 2020, representing 12 football fields in an already fully built city. Concrete results also include the designation of 39 biodiversity areas and the planting of over 130,000 new trees under the Tree Plan between 2020 and 2025. Aquatic biodiversity is also recovering: the Seine now hosts more than 30 fish species, compared to just three in the 1970s, reflecting a significant ecological rebound.
Feasibility
The feasibility of Paris’s biodiversity strategy is underpinned by strong financial, logistical, and institutional support. The Department of Green Spaces and Environment employs more than 3,000 staff dedicated to designing, procuring, managing, maintaining, and expanding nature in the city, making biodiversity a clear political priority of the current mandate.
Financially, Paris has invested significant resources. Between 2018 and 2022, the “Oasis schoolyards” programme was allocated €37 million, including €13.2 million in external co-funding (36%) from the Seine-Normandie Water Agency, the French National State, and the European Union. The Participatory Budget financed 322 nature-related projects worth over €11 million in the same period, empowering citizens to co-create new biodiversity spaces. Dedicated subsidies also support private action, such as the Copr’Oasis scheme, which funds de-paving, green roofs, and façades, and rainwater harvesting in co-owned buildings.
At the policy level, biodiversity criteria are now systematically integrated into public procurement: in 2022, 42.5 per cent of city contracts included biodiversity-related execution clauses or selection criteria, ensuring contractors adopt low-impact practices. New financing tools have also been developed, such as the Paris & Greater Paris Carbon Cooperative, which channels local actors’ investments into urban projects that both offset carbon emissions and strengthen biodiversity. In parallel, a new local “Nature in the City” label is being designed to support projects not covered by existing national or international schemes.
These combined instruments (staff capacity, dedicated budgets, external co-funding, procurement obligations, and innovative financing) demonstrate both the feasibility and long-term viability of Paris’s initiative.
Multi-Stakeholder Support
Stakeholder support is a cornerstone of Paris’s biodiversity strategy, reflected in strong citizen participation, institutional partnerships, and cross-sector collaboration.
Citizen involvement is central: more than 2,000 greening permits have enabled residents, associations, and businesses to green tree bases, sidewalks, and courtyards. About 1,160 nesting boxes and “Sparrow Quarters” support the recovery of sparrow populations. Large-scale events, such as Paris Sème and the Fête des Jardins, further engage the public and raise ecological awareness.
Collaboration with NGOs and scientific institutions underpins the initiative. A 2019 agreement with the Ligue pour la Protection des Oiseaux created 28 refuges in parks and cemeteries, while 475 municipal sites now hold the EcoJardin label, ensuring ecological management practices. Numerous research collaborations guide biodiversity monitoring and planning, including work with the IUCN on the implementation of the Urban Nature Index.
This multi-actor approach is matched by cross-sector coordination within the city administration. Urban planning integrates ecological corridors through the Bioclimatic Local Urban Master Plan, water services implement rain gardens and permeable soils under the Paris Rain Plan, and public works redesign streets to include vegetation and cycle paths.
Together, these actions demonstrate broad support and collective ownership, ensuring that biodiversity is embedded across policies, disciplines, and governance levels, turning Paris’s nature-positive vision into a shared citywide effort.
Management and Maintenance
Paris has embedded biodiversity management and maintenance into the regulatory framework of its Bioclimatic Local Urban Master Plan, ensuring that nature-positive outcomes are sustained over time.
The Orientation for Planning and Programming on Biodiversity and Climate Adaptation applies to all new developments and, where feasible, to existing buildings. It requires project owners to conduct a pre-construction ecological assessment to identify existing vegetation, habitats, and site vulnerabilities. To support this process, developers can use the BiodivScore tool. Each project must demonstrate how it will preserve and enhance biodiversity, integrate permeable soils, and minimise soil sealing, with compensatory measures required when residual impacts remain unavoidable.
Long-term resilience is ensured through strict planting requirements: species must be climate-resilient, low-water-demanding, and predominantly native, and projects must integrate multiple vegetation layers to strengthen ecological stability. The city provides free advice on tree species adapted to climate change in Paris on its website through a species guide. Built structures are subject to greening obligations, including intensive green roofs and façades and even biosolar roofs, combining vegetation with solar energy production.
Compliance with these requirements is systematically assessed during the building permit process, where the Green Spaces Department reviews around 600 urban planning applications each year, providing expert recommendations to improve the ecological quality of projects. Moreover, compensation strategies, such as creating new green spaces or converting impermeable surfaces, guarantee that ecological functions are maintained over time.
Measuring and Reporting Impact
Monitoring Results
Measuring biodiversity is inherently complex, but Paris has committed to basing its actions on robust, science-based indicators. Since 2015, the city has calculated its Singapore Index on Cities’ Biodiversity every five years. This globally recognised framework is built on 25 indicators covers species health, ecosystem services, and governance. The improvement of Paris’s score between 2015 and 2020 demonstrates steady progress, with a new assessment scheduled for 2025.
Building on this, Paris will pilot its first Urban Nature Index (UNI) with the IUCN Urban Alliance in 2025, combining quantitative and qualitative data on species status, ecosystem conditions, and human pressures. In parallel, the city is developing a biodiversity footprint methodology, addressing both domestic impacts and those linked to the production of goods and services consumed locally. Under the new Biodiversity Strategy, the city has committed to developing a methodology for calculating its biodiversity footprint.
These protocols ensure that Paris’s Nature-based Solutions are guided by evidence, allow for adaptive management, and guarantee that progress towards a nature-positive city is measurable, transparent, and actionable.
Demonstrating Progress
Systematic monitoring strengthens Paris’s ability to demonstrate progress and scale up its ambitions. Tools such as the Observatory for Ecological and Social Transition, yearly reporting on the progress of the implementation of the Tree Plan and Biodiversity Plan, and open data indicators published online support monitoring. Together, they enable continuous tracking of greening projects, tree planting, soil permeability, and habitat restoration.
Participation in the C40 Urban Nature Accelerator enhances benchmarking, sharing of best practices, and international visibility. These measurable results help Paris attract funding and support from European funding (such as UNP+ and ReGreeneration Horizon Europe projects) and justify new local investments.
Monitoring outcomes also shape policy evolution: they inform updates to the Bioclimatic Local Urban Master Plan, guide the prioritisation of future projects, and underpin innovative funding tools such as the Coopérative Carbone and the forthcoming “Nature en Ville” (Nature in the City) label.
By linking data to decision-making, Paris ensures that each success becomes a lever for further action and investment.
Measuring Impact
Paris is now recognised as a major player in climate change adaptation through Nature-based Solutions and urban nature projects. Paris’s initiatives are assessed through both quantitative and qualitative indicators. Since 2018, Paris has installed 138 hectares of vegetated roofs and walls, planted 133,000 additional trees between 2020 and 2024, and created 39 biodiversity areas. Aquatic ecosystems have also improved, with fish diversity in the Seine rising significantly.
Flagship projects such as Pariculteurs are now extended beyond Paris in partnership with the Seine-Saint-Denis circumscription and the Grand Paris Metropolis. They illustrate how local action drives broader regional transformation. Paris also reports its progress internationally through initiatives such as the IUCN Urban Nature Index, aligning with global biodiversity and climate goals.
Together, these measurable outcomes, published via municipal open data platforms, biodiversity reports, and international reporting frameworks, demonstrate Paris’s leadership in building a nature-positive city and advancing climate adaptation.
Learning and Transferability
Adaption and Enhancement
Paris’s initiative has continuously evolved through an adaptive and participatory approach. The Bioclimatic Local Urban Master Plan embodies lessons learned from monitoring biodiversity progress and stakeholder feedback. Its revision process was highly collaborative, involving public consultations, thematic workshops, and the Parisian Committee for Biodiversity and Nature, which brought together experts, civil society, and local communities.
This inclusive governance led to concrete design improvements in new projects, such as the Germaine Tillon swimming pool and the James Baldwin media library, where biodiversity considerations, including permeable soils, native plant palettes, and wildlife habitats, were fully integrated from the outset. These adjustments reflect a dynamic governance model where monitoring results directly inform planning and external stakeholders actively shape outcomes, ensuring that initiatives remain relevant, effective, and science-based.
Potential for Replication
The initiative’s influence extends beyond individual projects, transforming Paris’s broader approach to urban greening. Monitoring outcomes have driven a complete revision of plant production practices in the city’s horticultural centres, prioritising native and climate-resilient species better suited to future conditions. This shift is already shaping planting strategies across public spaces and influencing procurement standards.
The programme has also catalysed changes in how municipal departments collaborate. It has strengthened cross-sectoral coordination between green space management, urban planning, water services, and public health. This integrated model is now embedded in the city’s operational culture, enabling a systemic response to climate and biodiversity challenges and fostering continuous learning.
Inspiring Other Cities
Paris’s experience is increasingly recognised as a source of inspiration for other cities. Its policies and tools, such as the Bioclimatic Local Urban Master Plan, biodiversity indicators, and large-scale greening initiatives like Pariculteurs, have been shared through international networks, including C40, Eurocities, and ICLEI. Paris regularly contributes to global forums, from Conference of the Parties (COP) climate and biodiversity conferences to specialised biodiversity events, where its strategies are discussed as replicable models.
The transfer of the Pariculteurs programme beyond Paris, in partnership with Seine-Saint-Denis and the Métropole du Grand Paris, demonstrates its adaptability to different urban contexts. With methodologies grounded in measurable outcomes and collaborative governance, Paris’s approach offers a scalable framework that other cities can tailor to their own needs, inspiring them to raise their urban greening ambitions and integrate biodiversity into planning at scale.
Further strengthening this global impact, Paris is a “lighthouse city” in the UNP+ (Urban Nature Plans+) Horizon Europe project, a European initiative dedicated to mainstreaming urban nature. Through peer-to-peer exchanges and shared governance tools, Paris supports other cities in integrating biodiversity into planning and decision-making. This collaboration accelerates the transfer of knowledge and helps cities adapt Paris’s tested strategies to their own environmental, social, and spatial contexts.
Resilience
Reducing Negative Impacts and Ensuring Sustainability
Reducing the carbon footprint is at the core of Paris’s nature strategy. The city prioritises renovation and adaptive reuse over demolition, a principle embedded in the Bioclimatic Local Urban Master Plan. This shift limits emissions from construction and preserves the historic urban fabric, while improving the energy performance of pre-1948 buildings that make up much of the city’s housing stock.
Circular economy principles further minimise the climate impact of the built environment. Projects such as Pavillon Keller, built with reclaimed materials and a reversible structure, illustrate how low-carbon construction is scaled in practice. The Bonneuil-sur-Marne reuse hub recycles up to 7,500 tonnes of paving stones annually. Public procurement now integrates criteria favouring recycled materials and design for disassembly.
Nature-based Solutions are also central to carbon reduction and resilience. Greening rooftops and façades, restoring permeable soils, and planting urban forests capture carbon, cool the city, and improve stormwater management. Together, these actions reduce unintended impacts and embed sustainability into every stage of urban transformation, ensuring that Paris’s biodiversity strategy contributes to both climate neutrality and long-term resilience.
Environmental Considerations
Efficient use of natural resources is at the core of Paris’s strategy, ensuring the initiative’s sustainability and long-term resilience. The city prioritises on-site resource cycles and Nature-based Solutions to avoid harmful practices such as importing topsoil or relying on potable water for irrigation. Instead, composted green waste and recycled soil substrates from urban sites are increasingly used to enrich soils locally, reducing transportation impacts and preserving rural ecosystems.
Water management follows the same principles. Paris promotes the use of rainwater and reclaimed water for irrigation, while vegetated roofs, façades, and permeable soils are designed to retain, filter, and reuse stormwater directly on-site. This “sponge city” approach reduces runoff, mitigates flood risks, and supports groundwater recharge. Paris has two water circuits: one for fresh water and one for non-potable water, heavily used in green spaces.
The built environment plays a crucial role: green roofs and walls act as water buffers and microhabitats, transforming buildings into ecological infrastructure. Combined with rain gardens, planted courtyards, and de-paved surfaces, these systems support urban biodiversity while reducing pressure on grey infrastructure.
By integrating soil regeneration, water reuse, and vegetation into building projects, Paris ensures that its greening efforts are both resource-efficient and ecologically restorative. This holistic approach strengthens biodiversity, enhances climate resilience, and embeds sustainability into the city’s urban fabric.
Use of Natural Resources
Paris integrates resource efficiency directly into building design and biodiversity policies to ensure long-term resilience. Rainwater and runoff are systematically recovered and reused for irrigation of green roofs, façades, and public spaces, reducing reliance on potable water. The ParisPluie Plan embeds water-sensitive planning into construction projects, requiring the rationalisation of networks and water management at the permitting stage.
Low-tech Nature-based Solutions such as permeable pavements, vegetated parking surfaces, and planted containers that filter and depollute roadway runoff are widely implemented. Projects such as Life Absorb use phytoremediation to clean stormwater from the ring road. Rain gardens and swales enhance infiltration and restore natural cycles.
By promoting local plant species for soil depollution and infiltration, Paris limits the import of topsoil and fosters habitats directly within the built environment. These measures link building transformation with ecological restoration, ensuring that urban greening strengthens biodiversity while conserving water and soil resources.
Initiative: Retrofitting Paris into a Biodiversity-Friendly City