Shaping global environmental decisions using socio-ecological models.

One of the most ambitious ecological studies of the past few decades was the Millennium Ecosystem Assessment (MA), which examined the consequences of ecosystem change for human well-being. The MA developed global ecological scenarios as a process to inform policy options, despite enormous uncertainties. These scenarios were based on an interlocking suite of models that forecast the future. Following the recent completion and publication of the MA, there is now movement towards making the value of ecosystem services an integral part of key policy decisions. Here, we review the MA approach and suggest areas where immediate progress can be made to increase the likelihood that decision-makers will embrace the vision of assessments such as the MA.