 The simple proposal that biomass is carbon-neutral put forward in the early 1990s has been superseded by the more nuanced proposal that for a particular bioenergy project to be carbon neutral, the total carbon sequestered by a bioenergy crop's root system must compensate for all the emissions from the related, aboveground bioenergy project.This includes any emissions caused by direct or indirect land use change.Many first generation bioenergy projects are not carbon neutral given these demands.