This paper examines the case of border cost levelling as a source of climate finance in accordance with the objective to reach US$100bn per year as proposed in the Copenhagen Accord. The author notes that it would be difficult to secure US$100 billion per year through normal public sector channels in view of the financial crisis and related problems in OECD countries. Therefore, the article argues that the revenue associated with charging for the carbon embodied in the international trade of carbon-intensive commodities is an attractive option. The article explains this option of WTO-compatible 'border carbon cost levelling', indicates potential revenues from its application to key carbon-intensive commodities, and outlines the potential ethical and political economy attractions of the option.