Nature-based solutions such as China’s ‘sponge cities’ can help cities address major planning challenges, including air and water pollution, water scarcity and extreme heat, all of which are being exacerbated by climate change.
It’s all in the name. As Pascal Mittermaier, Global Managing Director for Cities at The Nature Conservancy, writes: “To make cities ‘greener’ – that is, less polluted, more resource-efficient, and more environmentally resilient – we should make them literally greener.” This is because many nature-based solutions are at least as cost-effective as conventional built infrastructure and can also address multiple urban planning challenges at once.
For instance, planting trees along streets can help reduce air pollution by filtering fine particulate matter and at the same time combat the urban heat island effect. And while their benefits may be highly localised, trees are particularly effective as a targeted intervention to protect vulnerable areas like schools or nursing homes. They can also help mitigate environmental inequality in lower-income, under-resourced neighbourhoods, which often have less canopy cover, explains Mittermaier.
Nature can also address water management challenges. For example, Chinese ‘sponge cities’ like Shenzhen use rain gardens, green roofs artificial wetlands to manage storm water, as well as permeable paving materials that allow water to filter through to the substrate.
Mittermaier is quick to point out that nature-based solutions alone cannot solve every urban challenge and measures such as clean-energy systems or efficient public transport are also needed. But he also forcefully argues that “we cannot solve the problems created by concrete and turbines with more concrete and turbines”.
Instead, we need flexible solutions that make our cities more resilient, sustainable and adaptable. “Nature itself can offer such solutions and be a catalyst for healthier, more vibrant neighbourhoods, driving investments and making cities more successful by any measure.”
Image credit: Arlington County via Flickr