By Maurus Lozza
Climate change and the loss of biodiversity are major threats worldwide, and their impacts can be particularly pronounced in cities. By simultaneously improving climate resilience, human well-being and ecological connectivity, green cooling infrastructure is an important element of sustainable urban development.
Because of their geographic extent and concentration of millions of people, most of the world's megacities are highly vulnerable to the consequences of climate change and hotspots for air pollution and disease. According to the United Nations Environment Program (UNEP), nature-based solutions not only promote local biodiversity, but also improve the quality of life and overall health situation in cities. Moreover, green cooling infrastructure can reduce the carbon footprint and enhance the ability to adapt to climate change in a cost-effective way. To be successful over the long term, nature-based solutions must be integrated into the infrastructure planning process at the earliest stage possible and tailored to local contexts. Cooperation across sectors andsubnational authorities is essential to achieve this. From a technological perspective, passive cooling solutions, such as green infrastructure, have a longer lifespan than active technologies and are generally more sustainable.
Reconnect with nature
For example, tree-shaded walking and cycling paths can be very effective in creating ecosystem and mobility corridors at the same time. Especially when combined with vegetation on green facades, green roofs and in city parks, islands of biodiversity can be interconnected to form valuable ecological networks. In addition, the cooling effect of plant respiration and shading can noticeably reduce the urban heat island effect. Other essential environmental services range from cleaner air and water to increased habitat for endangered species and corridors for pollinators. Finally, green infrastructure like city parks play an important role in people's social lives by providing recreational spaces and helping them connect with nature.
Balance trade offs
However, there can be unintended consequences when green space expansion leads to the spread of undesirable organisms such as invasive species or mosquitoes that negatively impact human health and local ecosystems. Conflicts can also occur between different sectors, such as when agricultural land is used as temporary flood control basins, transferring flood risk from urban residents to farmers. Other challenges include funding and management of green infrastructure. In general, encouraging and supporting small local businesses to apply nature-based solutions will stimulate innovation and add local value. Quantifying these economic benefits can help build a compelling narrative. To ensure that nature-based solutions are locally adapted and realize their full potential, it's important to involve all stakeholders, including local communities and youth.
More and more policies have recognized the opportunity to tackle climate change and biodiversity together. Nature-based solutions offer great potential for combining their respective goals and measures. One way that nature-based solutions can be effectively implemented is through the protection, restoration and creation of ecosystems that have a high capacity to sequester carbon dioxide (CO2). A case study in Athens,
Greece, showed that connecting two city parks with a green corridor resulted in a 30% increase in biodiversity in the area, sequestration of 27.9 tons of CO2 per year and an 85% reduction in dust particles. An important open question that needs further research is whether and how nature-based solutions should be translated into binding regulations, and at what scale this would be most effective? In any case, citizens can 9
and should take action themselves today by making their own environment as biodiversity-friendly as possible and supporting local sustainable projects!