Exploring the use of a macro-micro-based approach to value biodiversity productivity impacts on the agricultural sector

In the last century the agricultural sector has been profoundly altered by both natural and anthropogenic factors, including climate change, changing world economies, changes in agricultural policies, including the Common Agricultural Policy (CAP), and the subsidies currently paid to European farmers and land managers. All these factors together affected, and still affect, crop productivities and agricultural land use patterns. In this context, various studies have focused their attention on the analysis of agricultural land use under scenarios of global climate change, computing projections on land use changes and respective land productivities induced by fluctuations in temperature and precipitation. However, fluctuations in temperature and precipitation are not the only channel for climatic change to impact agro-ecosystems. Biodiversity is also subject to climatic fluctuations, which, in turn, might impact land productivity. The present chapter aims at analysing the economics of the climate-change-induced impacts on biodiversity in the agricultural sector, including its estimation in terms of changes in agricultural land productivity (and, above all, the geo-climatic impacts, as available from the state-of-the-art literature - see Brown and Rosenberg, 1999; Rounsevell et al., 2005; and Kan et al., 2009 as an illustration of a few representative examples). The proposed economic valuation of consequences of climate-change-induced impacts on biodiversity is anchored in a three-step approach.