In late October 2007, a UN expert called for a five-year moratorium on biofuels, the reason being that in a time when more than 800 million people are starving, converting food crops into fuel so that wealthy people can drive and fly is a violation of social equity and human rights.
2007 年 10 月底，聯合國專家提出「生物燃料暫緩 5 年」的呼籲。因為，在全球飢餓人口還有 8 億多人時，將生產農作物的土地轉植生質能源作物，以供有錢人開車、搭機，是違反社會公平與人權的。