There is a need to balance increasing demands for food, fuel and fibre with long-term sustainability of land use.Sustainable intensification can, in theory, offer a window of opportunity for the intensification of land use without causing degradation. This potentially allows the sparing of land to provide other ecosystem services, including carbon sequestration and the protection of biodiversity. However, the potential for SI is system specific and may change through time (indicated by grey arrows). Current practice may already be outside of this window and be unsustainable in terms of negative impacts on the long-term sustainability of the system.