worldwide use of liquid biofuels grew rapidly during the past 10-15 years, and has accelerated remarkably just since 2005. Production is expected to double by 2015. While most production today occurs in Brazil and the US, increases production is expected not only in these countries but in Europe, southeast Asia, and Africa.

The increased production of just that past 3 years has started to place major strains on the global food system, with global cereal stocks at their lowest levels since the early 1980s. Liquid biofuels (ethanol and biodiesel) are still viewed as greenenergy sources by some, but criticism of biofuels has also grown remarkably over the past year.

Much of the criticism has focused on first-generation ethanol, that is ethanol produced from corn, and many articles in both the scientific literature and the popular press have reported on a host of environmental problems associated with this technology. Potential issues with ethanol produced from sugarcane, with biodiesel produced from oil palms, soybean, and other crops, and with second-generation ethanol produced from cellulose, have received far less scrutiny and discussion so far. There are nonetheless potentially severe consequences on the environment from these technologies as well.

The charge of the International SCOPE Biofuels Project is to perform an objective, science-based assessment in order to provide a comprehensive, systematic, and comparative analysis of the environmental benefits and costs of biofuel technologies. The project is being conducted both at the global (phase 1) and sub-global (phase 2) levels, so as to take into account specific physical and societal dimensions in the main regions of the world. The project is evaluating both first and second-generation liquid fuels, including both ethanol and biodiesel.

The project is also evaluating gaseous biofuels (methane) and the use of solid biomass for energy (for example through pyrolysis and direct combustion) There are many other organizations involved in evaluating biofuels. What can the SCOPE effort do that is not already being done by others?

The SCOPE Biofuels Project not only can bring significant added value to the topic of how biofuels affect global change and environmental quality, but can also play a unique role. Other ongoing efforts are governmentally based or built on industrial consortiums or on industrial/NGO coalitions. While these involve scientists, none are primarily science-based. The SCOPE project has established an international and interdisciplinary advisory group of distinguished scientists and engineers.

A subset of this group serves as an executive committee for the Project. We have established a fundamental goal: to use the best available science-based objective information to address the question what are the characteristics of an environmentally desirable and sustainable biofuel?