The paper examines environmental management accounting as a tool that supports environmental investment decision-making in the context of the emerging markets for carbonised rice husk and the clean development mechanism. Based on a case study at Oliver Enterprises, a rice milling business in the Philippines, the paper analyses carbonisation and cogeneration as two processing alternatives to reduce environmental and social impacts related to the conventional way of rice husk disposal and to improve the overall performance of the rice mill. Implications for corporations and for policy decision-making are examined. © 2008.