Quantifying the climate impacts of albedo changes due to biofuel production: a comparison with biogeochemical effects

Fabio Caiazzo,Robert Malina,Steven R H Barrett,Steve H L Yim,Philip J Wolfe,Mark D Staples

doi:10.1088/1748-9326/9/2/024015

Abstract

Lifecycle analysis is a tool widely used to evaluate the climate impact of greenhouse gas emissions attributable to the production and use of biofuels. In this paper we employ an augmented lifecycle framework that includes climate impacts from changes in surface albedo due to land use change. We consider eleven land-use change scenarios for the cultivation of biomass for middle distillate fuel production, and compare our results to previous estimates of lifecycle greenhouse gas emissions for the same set of land-use change scenarios in terms of CO2e per unit of fuel energy. We find that two of the land-use change scenarios considered demonstrate a warming effect due to changes in surface albedo, compared to conventional fuel, the largest of which is for replacement of desert land with salicornia cultivation. This corresponds to 222 gCO2e/MJ, equivalent to 3890% and 247% of the lifecycle GHG emissions of fuels derived from salicornia and crude oil, respectively. Nine of the land-use change scenarios considered demonstrate a cooling effect, the largest of which is for the replacement of tropical rainforests with soybean cultivation. This corresponds to − 161 gCO2e/MJ, or − 28% and − 178% of the lifecycle greenhouse gas emissions of fuels derived from soybean and crude oil, respectively. These results indicate that changes in surface albedo have the potential to dominate the climate impact of biofuels, and we conclude that accounting for changes in surface albedo is necessary for a complete assessment of the aggregate climate impacts of biofuel production and use.

Highlights

Biofuels may hold promise to promote energy security, reduce the environmental impact of transportation and foster economic development
This study shows that changes to surface albedo due to biomass cultivation can have a significant impact on the aggregate climate impact of biofuels
The albedo effects of LUC related to biomass feedstock cultivation for biofuel production, shown in figure 1, are on the same order of magnitude as the biogeochemical effects calculated by traditional LCA for the same LUC scenarios

Summary

Introduction

Biofuels may hold promise to promote energy security, reduce the environmental impact of transportation and foster economic development. For these reasons, many countries have enacted policies to encourage their production In the US, biofuel production for transportation aims to replace 30% of petroleum consumption by 2030 (Perlack et al 2005, US Department of Energy 2011). Targets are set for the EU (10% replacement of diesel and gasoline by 2020; EU 2009) and other countries such as China (2 million tons of biodiesel by 2020; Koizumi 2011) and Indonesia (20% replacement of diesel and gasoline by 2025; Zhou and Thomson 2009)

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Results

Conclusion