Policy Brief: How cost effective are Nature based Solutions to climate change adaptation?

There is growing recognition that nature-based solutions - i.e. restoration and protection of natural habitats - when applied strategically and equitably can not only safeguard biodiversity and ecosystem services but also help people adapt to the effects of climate change. NbS include the restoration of coastal ecosystems to protect communities from storm surges and erosion, agroforestry to stabilise crop yields in drier climates, and forest restoration in headwaters and riparian zones to secure and regulate water supplies and protect communities from flooding, soil erosion, and landslides.

But how cost-effective are NbS compared to alternative adaptation approaches? A recent semiquantitative review commissioned by the Royal Society (2014) compared NbS (focussing on ecosystem-based adaptation), hybrid and engineered approaches to reducing risks to people from extreme weather events (coastal and riverine flooding, heatwaves, drought) using a combination of literature and expert scores and opinion. The study compared the effectiveness of each option (encompassing both magnitude of the event against which the intervention can be effective and spatial scale over which it is effective) versus its affordability (combining both initial and long-term [to 2050] costs of intervention). It also scored intervention with respect to the number of co-benefits it brought.