The lack of a precise definition for the term 'nature-based solutions' risks making it seem arbitrary and impractical (see Nature 541, 133–134; 2017). We therefore propose three criteria for applying these solutions that will strengthen the concept's role in improving policy on well-defined societal challenges.

First, nature-based solutions need to provide simultaneous benefits for society, the economy and nature. Second, the term should be understood to represent a transdisciplinary umbrella that encompasses experience from existing concepts such as 'blue–green infrastructure' in engineering, 'natural capital' and 'ecosystem services' in economics, and 'landscape functions' in environmental planning. Third, a nature-based solution needs to be introduced gradually, to allow time for careful assessment of its application in real-life settings and further refinement.

Examples of nature-based solutions that respect these three criteria include coastal management to mitigate the effects of climate change, and restoration of floodplains to reduce the risk of downstream flooding. Such initiatives can stimulate cooperation between actors from science, policy and practice.