Potential emissions of Kyoto and Non-Kyoto climate active compounds in the production of sugarcane ethanol

sugarcane ethanol is the most commercially developed liquid biofuel. the potential emissions of kyoto and non-kyoto protocol climate active compounds in the production of sugarcane ethanol in agricultural lands are evaluated herein. various scenarios are considered, such as low or high n2o emission from n-fertilizers, inclusion or not of pre-harvest burning, uncontrolled or controlled emissions in bagasse based boilers, and 20 or 100 years time horizons in gwps. the co2 emitted in ethanol fuel combustion is recycled during sugarcane "re-growing" and does not count as greenhouse gas. however, even though many uncertainties remain, the available information allows estimating that co2-eq emissions are very large when ethanol production is based on pre-harvest burning and there is non-controlled particle emission in boilers. in these scenarios, compared with the combustion of equivalent amounts of gasoline, higher co2-eq emission would take place. halting sugarcane field burning would not be sufficient to revert the situation, especially in a 20-years time horizon. only when more environmental friendly procedures are applied, a significant saving of co2-eq emissions occurs at 20 and 100-years horizon scenarios. in all scenarios, non-kyoto protocol compounds make an important net contribution. therefore, if a real evaluation of climate active compounds emissions is to be reached, it would be crucial to include these compounds in life cycles studies. to reduce uncertainties, especially of non-kyoto compounds, additional research is needed.