BIOFUELS AND THE ENVIRONMENT

Biofuels and the Environment

Biofuels and the Environment

Introduction

The rise of biofuels has sparked intense interest, both public and scientifi c, concerning energy issues, agricultural issues and of course environmental issues, particularly global warming. The debate over biofuels has largely turned on the validity of claims made for their saving of greenhouse gas (GHG) emissions.

Biofuels and the Environment

Biofuels would be carbon-neutral (in principle) if all the carbon released through combustion as fuel were drawn from carbon absorbed by the plants during photosynthesis. But in practice, of course, fossil fuels are used at various stages in the life cycle of biofuels, with diff erent results depending on where the boundary of the system to be analyzed is drawn. One way of drawing such boundaries takes into account not just the life cycle eff ects of growing the biofuel crops and harvesting and processing the product, but deforestation or conversion of grazing land to crop cultivation, induced by the expansion of biofuels demand. These are known as indirect land use change (ILUC) eff ects, and they have come under particular scrutiny in the past year. No-one denies that ILUC eff ects are real. The issue is rather whether they can be measured, and, if so, whether they can be quantifi ed in a form that could underpin regulatory measures designed to safeguard sustainability.

A paper published in Science in February 2008 stands out in this regard, for the bold and unqualifi ed form of its pronouncement.2 In a paper co-authored by many of the participants in US debates and coordinated by Tim Searchinger, of the Woodrow Wilson School at Princeton University, the claim is made quite unambiguously that if ILUC eff ects are quantifi ed in relation to a hypothesized spike in US corn ethanol consumption of 56 billion liters above projected levels up to the year 2016 (the goal for biofuels set by the US Congress) then the impact of the ILUC triggered around the rest of the world would be the release of a further 3.8 billion tonnes of carbon dioxide equivalent (CO2 equivalent) into the atmosphere. These GHG emissions would be over and above direct eff ects caused by the combustion of the ethanol. Clearly if the Searchinger et al. calculations are valid, then they would constitute an indictment of biofuels policy in the USA and by implication, around the world. The criticism would be devastating. But are the claims valid - or even plausible? Th is is an important question, because already the Searchinger et al. results have set in motion deliberations by the Environmental Protection Agency (EPA) in the USA and by the EU in Europe over inclusion of requirements to reduce life cycle GHG emission standards in environmental regulations governing biofuels. For example, the EPA is debating rule-making pursuant to the 2007 Energy Independence and Security Act (EISA) where the reductions in GHG emissions produced over life cycle calculations are required to include indirect as well as direct ...