In the current issue of Nature researchers show that marginal lands represent a huge untapped resource for growing cellulosic biomass. Using marginal land could provide up to 215 gallons of ethanol per acre with extensive greenhouse gas mitigation. This is the first study to provide an estimate of the greenhouse has benefits as well as an assessment of total production potential. Not only will the use of marginal land create a new revenue for farmers and agricultural investors but there will be no indirect land use effects and no carbon debt from land conversion.