This is from the Web-site of the IUCN:
"Nature-based solutions are interventions which use nature and the natural functions of healthy ecosystems to tackle some of the most pressing challenges of our time. These types of solutions help to protect the environment but also provide numerous economic and social benefits.
Creating or restoring green spaces in cities, for example, can increase tourism revenues, provide recreational opportunities for citizens, and help lower temperatures and pollution levels in urban areas. Building oyster reefs in coastal areas can provide a nature-based solution to coastal erosion and storm surges, while also filtering contaminated seawater, fostering biodiversity, and supporting local fisheries.
IUCN works with governments, the private sector and the scientific community to raise awareness of the benefits of these types of solutions, and translate the latest science and knowledge on nature-based solutions into support and guidance for practical implementation."