A roof garden as a community green space in Valletta urban area

Description: A roof garden has been set up on the main building of the Cluster, which will include various features including a small pond and a lot of green spaces with mainly indigenous shrubs and trees. It will also be used to promote green initiatives linked to environmental education through the installation of facilities suitable for holding meetings for small groups of participants. (Valletta Design Cluster, (s.a.)

Country: Malta

City: Valletta

City size: 85 ha

Population: 5750

start: 2017

Timeframe: 3 years

Phase: Ongoing

Nature-based solutions (NBS) : Yes

Initiator: Valletta Design Cluster within the Valletta Cultural Agency

Website source: https://culture.gov.mt/en/VallettaCulturalAgency/Pages/Valletta-Design-Cluster.aspx

Latitude: 35.9009

Longitude: 14.5137

Co-benefits

Increased infiltration, water retention and flood protection

Yes, green roofs can slow down runoff generation, and therefore contribute to providing flood protection benefits to the surrounding areas.

Reduced drought risk, cooling effect, urban heat island mitigation

Yes, a green roof acts as insulators for buildings (United States Environmental Protection Agency, 2019) and plants absorb and reflect sunlight (Sempergreen, 2019); so this helps to create a cooler and more pleasant climate. For the indoor climate this means that the air conditioning doesn't have to work so hard, which in turn means energy savings. And this too has an extra positive effect on the climate in the immediate vicinity of the building and on the temperature in the city (Sempergreen, 2019). Reduced air pollution and greenhouse gas emissions: By lowering air-conditioning demand, green roofs can decrease the associated air pollution and greenhouse gas (GHG) emissions from conventional power sources (United States Environmental Protection Agency, 2019).

Biodiversity conservation or increased biodiversity

Yes, green roofs provide habitats for plant and animal species in urban areas (ERA, 2018d).

Increased quality and quantity of green and blue infrastructures

Yes, introducing green space into the built environment with limited availability of green infrastructure (Balzan et al., 2018; Balzan, 2018).

Sustainable urbanisation

Yes, enhancing natural capital in the urban area. A green roof improves human comfort, by reducing heat transfer through the building roof, can improve indoor comfort, and lower the incidence of heat stress associated with heat waves. (United States Environmental Protection Agency, 2019). Areas with more greenery suffer less hinder from aggression, violence and vandalism. (Sempergreen, 2019). A green roof could help to develop also programs for encouraging “hazard-resistant landscaping”by planting native trees,that tend to fare well in the face of high winds. Biophilic urbanism can help to protect or strengthen favorable climatic and micro-climate conditions in cities. The power and value of biophilic urbanism as an urban resilience and sustainability strategy is clear, and a number of cities developed and are implementing ambitious programs for expanding the nature in and around them. (Beatley, Newman, 2013; Hazard Resistant Landscaping, (s.a.). Green infrastructure, as a NbS, is especially important for countries like Malta due to the disproportionate urban sprawl and population density. On account of the small size of the Islands, strategically-set-up green infrastructure will improve the living experience for urban residents by providing better air quality, as well as greater psychological wellbeing through more open living space and closer contact with nature. The relatively short distances involved make for easy access to any green infrastructure set-up anywhere within the country.

Improved aesthetic value

Yes, green roofs provide aesthetic value in the built environment. (United States Environmental Protection Agency, 2019). In this case, the roof garden is being developed on top of a renovated building.

Increased access to green infrastructure

Yes, provision of green space for enjoyment and reconnection staff, visitors and public and nature by supporting urban biodiversity (ERA, 2018e).

Increased willingness, participation, investment in NBS

Yes, the functions of the identified spaces have been identified through a meticulous research process aiming to give voice to the community needs of (creative) spaces in Malta (Valletta Design Cluster, (s.a.).

Education, knowledge exchange and learning

Yes, the participation of communities is expected to provide an opportunity for knowledge exchange, education and learning.

Original problems

Low air quality

National data indicates exceedances of the EU limit values have been observed for both ozone and particulate matter (PM10). PM10 exceedences are attributed to the combined effect of human caused (traffic congestion and to a minor extent power generation) and environmental factors (e.g. dust from the Sahara). Ozone is a transboundary pollutant arriving in Malta from Europe. The concentration of Nitrogen Dioxide (NO2) higher in traffic congested areas and may pose a significant problem in dense urban areas (ERA, 2018b).

Drought and heat risk

The Mediterranean Region is considered as a "hot-spot" of climate change, having been identified in global climate scenarios as one of the most responsive regions to climate change (Lionello and Scarascia, 2018). There is a consensus in scientific literature that average temperatures will rise across most of the Mediterranean Region, and that precipitation will decrease (Ulbrich et al. 2013; Lionello and Scarascia, 2018). Observed annual mean temperatures in the Mediterranean Region are now 1.4 °C higher than the average late-nineteenth-century levels particularly during the summer months (Cramer et al., 2018).

Loss of biodiversity

Yes, Malta’s biodiversity continues to experience various pressures and threats, with natural biotic/abiotic processes, invasive/other problematic species and genes, natural system modifications, human interference and disturbances, and natural system modifications being the most significant pressures. Malta’s National Biodiversity Strategy and Action Plan (NBSAP) has 19 national targets and 6 EU Biodiversity Strategy targets that will eventually contribute towards the fulfilment of the EU and global targets to reduce pressures on biodiversity. Furthermore, the first review for the progress status of implementation of Malta’s NBSAP measures towards achieving the Aichi targets covered the period up to 2014. Seventeen out of 20 Aichi targets had a good progress status and require further action to be achieved successfully by 2020. Two of the targets have an excellent progress status and one has a limited progress status. The same review report provides the status of progress on the implementation of the eighty NBSAP measures. More than half of the measures had a good progress status (47 measures) while excellent progress was observed in 14 measures. However, 5 measures required further progress but another 14 measures had a not yet been assessed. (ERA, 2018d). The government has introduced various policies to preserve Malta’s biodiversity, as the small island is home to a “varied and interesting array of habitats and hosts endemic, indigenous, and migratory species”, as stated in the National Environment Policy. The policy outlines measures to halt the loss of biodiversity by 2020. Yet Malta’s biodiversity continues to be threatened by land development, invasive species, over-exploitation of species and climate change. (Malta Voluntary National Review on the implementation of the 2030 Agenda, 2018).

Low availability of green infrastructure

Yes, because of the lack of green areas and open spaces due to urban expansion and the growing number of people living in urban areas (ERA, 2018d). Densely populated urban areas were characterised by a lower availability of green infrastructure (Balzan et al., 2018)

Low aesthetic value

Yes, the roof garden is located on top of a renovated and restored historic building in a dense urban areas.

Lack of local sense of ownership, participation

Limited knowledge about biodiversity

The Malta National Biodiversity Strategy and Action Plan (NBSAP) reports that the results of the Eurobarometer Surveys on Attitudes of Europeans towards Biodiversity in 2007 and 2010 indicate that 14.4% and 18% respectively of Maltese respondents had heard of the term “biodiversity” and knew what it meant. A survey commissioned by MEPA in 2011 indicates that out of the 500 persons interviewed, 24.6% of Maltese respondents heard of the term “biodiversity” and knew what it meant. In general there is a need to continue enhancing biodiversity awareness and gain more knowledge on the meaning of ‘biodiversity’ (ERA, 2018d).

SDGs

Good health and well-being (SDG3)

Yes, urban greenery contribute significantly to mental health and well-being.

Sustainable cities and communities (SDG11)

Yes, green surfaces can enhance urban sustainability by improving public welfare, economic status and maintaining social justice.

Climate action, resilience, mitigation and adaptation (SDG13)

Yes, green roofs can mitigate the urban heat island effect and reduce cities' greenhouse gas emissions by reducing energy use in buildings.

Reference: Balzan, M. V., Caruana, J., Zammit, A. 2018. Assessing the capacity and flow of ecosystem services in multifunctional landscapes : Evidence of a rural-urban gradient in a Mediterranean small island state. Land Use Policy, 75, 711–725. Retrieved from: https://doi.org/10.1016/j.landusepol.2017.08.025.

Balzan, M. V. 2018. An assessment of green infrastructure and ecosystem services in the Valletta urban area: a case-study for sustainable urban planning. Information obtained: 2019-11-22. Available at: https://oppla.eu/casestudy/19309.

Beatley, T., Newman, P. 2013. Biophilic cities are sustainable, resilient cities. Sustainability 5(8):3328–3345. Available at: https://www.mdpi.com/2071-1050/5/8/3328/htm.

Cramer, W., Guiot, J., Fader, M., Garrabou, J., Gattuso, J.-P., Iglesias, A., Lange, M.A., Lionello , P., Llasat , M.C., Paz, S., Peñuelas, J., Snoussi, M., Toreti , A., Tsimplis, M.N., Xoplaki, E. 2018. Climate change and interconnected risks to sustainable development in the Mediterranean. Nature Climate Change. doi:10.1038/s41558-018-0299-2.

ERA. 2018b. State of the Environment Report 2018: Chapter 2: Ambient Air. Reporting status from 2009 to 2015. Information obtained: 2019-11-08. Available at: https://era.org.mt/en/Documents/3_Chapter2_AmbientAir_9Aug18.pdf.

ERA. 2018d. State of the Environment Report 2018: Chapter 8: Biodiversity. Reporting status from 2009 to 2015. Information obtained: 2019-11-08. Available at: https://era.org.mt/en/Documents/Chapter8_Biodiversity_04Dec18.pdf.

ERA. 2018e. Investing in the Multi-functionality of Green Infrastructure (GI) – An Information Document to support GI Thinking in Malta. Information obtained: 2019-11-08. Available at: https://era.org.mt/en/Documents/GI_InformationDocument-Consultation-ERA-18.pdf.

Hazard Resistant Landscaping. Charleston, South Carolina, (s.a.). Information obtained: 2019-11-10. Available at: http://www.charlestoncounty.org/printer/www/departments/BuildingInspections/ProjectImpact/landscaping_Brochure.pdf.

Lionello, P., Scarascia, L. 2018. The relation between climate change in the Mediterranean region and global warming. In Regional Environmental Change, 2018, Volume 18, Issue 5, pp 1481–1493. Malta Voluntary National Review on the implementation of the 2030 Agenda. 2018. Information obtained: 2019-11-01. Available at: https://sustainabledevelopment.un.org/content/documents/20203Malta_VNR_Final.pd.

Sempergreen. 2019. Benefits of a green roof. Information obtained: 2019-11-03. Available at: https://www.sempergreen.com/en/solutions/green-roofs/green-roof-benefits.

Ulbrich U, Xoplaki E, Dobricic S, García-Herrera R, Lionello P, Adani M, Baldi M, Barriopedro D, Coccimiglio P, Dalu G, Efthymiadis D, Gaetani M, Galati MB, Gimeno L, Goodess CM, Jones PD, Kuglitsch FG, Leckebusch GC, Luterbacher J, Marcos-Moreno M, Mariotti A, Nieto R, Nissen KM, Pettenuzzo D, Pinardi N, Pino C, Shaw AGP, Sousa P, Toreti A, Trigo RM, Tsimplis M. 2013. Past and current climate changes in the Mediterranean region. In: Navarra A, Tubiana L (eds) Regional Assessment of Climate Change in the Mediterranean. Springer, Dordrecht, pp 9–52. https://doi.org/10.1007/978-94-007-5781-3_2.

United States Environmental Protection Agency. 2019. Using Green Roofs to Reduce Heat Islands. Information obtained: 2019-11-10.Available at: https://www.epa.gov/heat-islands/using-green-roofs-reduce-heat-islands.

Valletta Design Cluster. (s.a.). The Valletta Design Cluster. Information obtained: 2019-11-22. Available at: https://valletta2018.org/infrastructure-projects/the-valletta-design-cluster/.