Taking stock of the empirical evidence on the insurance value of ecosystems

Ecosystems can buffer against adverse events and, by so doing, reduce the costs of risk-bearing to society; benefits which have been termed ‘insurance value’. Although the terminology is recent, the concept is older and has its roots in ecological resilience. However, a synthesis of studies through the lens of the insurance value concept is lacking. Here we fill this important knowledge gap by conducting a rapid evidence assessment on how, where and why the insurance value of ecosystems has been measured. The review highlighted the often substantial positive values that were associated with restoration, rehabilitation or avoidance of loss of natural ecosystems. However, many regions, ecosystems and hazards are not widely researched. Most studies focused on forests, agriculture and wetlands, often with an emphasis on habitat restoration to reduce flood risks. Over half the studies provided non-monetary or monetary estimates of value, reporting, for example, improved ecological function, achieved/achievable cost reductions or willingness-to-pay. Nevertheless, the evidence-base remains fragmentary and is characterised by inconsistent reporting of valuation methodologies. This precludes drawing general conclusions. We recommend that future studies of insurance value adopt a common approach to facilitate the development of a more robust evidence-base.