Biomass is an important energy feedstock and an alternative to fossil fuel. The development of biomass-based supply chains and energy conversion plants has to be calibrated to reflect local sustainability criteria. The aim of this study is to assess the environmental, economic, and social sustainability of a biomass-based district heating plant (DHP) and a combined heat and power plant (CHP) in Italy. The sustainability assessment was developed using three criteria: proximity between biomass and the energy producer and consumer; value added, employment, and impact of biomass supply chains; and environmental impacts. For each criterion, a set of sustainability metrics was developed and tested in two case studies in Northern Italy (Sarentino DHP and Cavalese CHP). The results suggested that the DHP and CHP (1) were supplied with local biomass residues located at distances of 11 km and 20 km, respectively; (2) provided energy to 55% and 83% of the total local population, respectively; (3) generated a value added of approximately €2 million and €1 million, created 4 and 8 local green jobs, and dedicated 52% and 64% of their external costs to the local biomass supply chain (wood production, transformation, and transport), respectively; and (4) contributed to the impact category of global warming potential with 7.6 gCO2eq./MJ (compared to 70–90 gCO2eq./MJ from fossil-fueled DHP) and 62 gCO2eq./MJeu (compared to 100–300 gCO2eq./MJeu from fossil-fueled CHP), respectively.

Human activities have the potential to enhance carbon sequestration by the world's forests and contribute to climate change mitigation. Voluntary carbon trading is currently the only option to pursue and reward carbon sequestration by forestry activities. Carbon credits for enhanced sequestration can be sold to partners wishing to offset their own emissions. Here we illustrate the steps taken to design guidelines for the generation of voluntary carbon credits by improved forest management in Piemonte, Italy. The guidelines have been developed in a joint effort by academia, regional administrations, forest owners and professional consultants. In particular, we show how to compute the baseline and the additionality of credit-generating forest management activities, and how to reconcile the generation of forest carbon credits with law requirements, technical limitations, and the provision of other ecosystem services. To illustrate the profitability of carbon credit generation, we simulated the application of carbon credit guidelines to two forest-rich mountain watersheds in the southern part of the Piemonte region. The two dominating tree species are beech (Fagus sylvatica L.) and chestnut (Castanea sativa Mill.). We computed current forest carbon stock and carbon credits generated in 20 years under business as usual and an alternative biomass retention scenario. The IFM resulted in an avoided harvest of 39,362 m 3 for a net total of 64,014 MgCO2e after subtracting harvest emissions, or 38 Mg ha -1 throughout the permanence period of 20 years. These steps can be replicated in other mountain regions where there is interest in promoting this ecosystem service as an alternative or an addition to production-oriented forest management.

No abstract

No abstract