Conference Agenda

Amongst the multiple advantages attributed to nature-based solutions (NBS) over conventional and grey infrastructure, is their characterisation as economically efficient, i.e. that the benefits that they generate outweigh their costs. However, surprisingly little attention has been paid so far to generating quantified evidence to support this claim in the form of comprehensive cost-benefit analysis informing actual and specific environmental decisions in given territories. Without such evidence, current enthusiasm for NBS might result in bad decisions or disappointment and abandonment. In this paper, we provide illustration of a co-constructed approach closely developed with policy-makers and involving a range of stakeholders, in which the well-being impacts of adopting NBS versus non-NBS alternatives for the mitigation of agricultural impacts in the ecologically stressed Mar Menor lagoon (Spain) are formally evaluated, building-up the evidence base of the economic efficiency of NBS. More importantly, the paper illustrates how there is now sufficient existing knowledge (with respect to ecosystem services provision and their values) to undertake rapid economic assessments that, if exposed and co-constructed with a range of stakeholders in participatory processes, can support complex policy decisions in response to climate and environmental emergencies in ways that are robust, transparent and socially acceptable. Such socially supported processes are of particularly critical importance in times of growing polarisation over environmental challenges.