Introduction

In this chapter we look at the costs and benefits of three possible interventions that would enhance the planet's biodiversity and improve its ecosystems over the next forty years. The results are based on a study carried out across four research institutes and coordinated by the Scottish Agricultural College (Hussain et al., 2011) that combined a global biophysical model (IMAGE-GLOBIO), which analyzed the biophysical impacts of different development scenarios compared to the counterfactual, with a set of valuation studies that placed monetary values on the outcomes resulting from the different policy options in terms of biodiversity and ecosystem services (ESSs).

While reference is frequently made in the popular press to biodiversity losses, in practice it is difficult to quantify and value them. There are several studies that attempt to do this in specific cases but no one has successfully estimated the value of the loss of biodiversity at a global level. This is because the links between biodiversity and biolo-gical systems and the economic and social values that they support are extremely complex. Even the measurement of biodiversity is problematic, with a multi-dimensional metric regarded as appropriate (Purvis and Hector, 2000; Mace et al., 2003), but with further work considered necessary to define the appropriate combination.