The essential role of other effective area-based conservation measures in achieving big bold conservation targets

Continued biodiversity loss has prompted calls for half of the planet to be set aside for nature – including E. O Wilson's “Half-Earth” approach and the Wild Foundation's “Nature Needs Half” initiative. These efforts have provided a necessary wake-up call and drawn welcome global attention for the urgent need for increased action on conserving biodiversity and nature in general. Yet they have also sparked debate within the conservation community, particularly due to the huge practical and political obstacles to establishing or expanding protected areas on this scale. The new designation of “other effective area-based conservation measures” (OECMs) provides the opportunity for formal recognition of and support for areas delivering conservation outcomes outside the protected area estate. We argue that OECMs are essential to the achievement of big and bold conservation targets such as Half-Earth. But integration of OECMs into the conservation estate requires fundamental changes in protected area planning and how the conservation community deals with human rights and social safeguards issues; it therefore challenges our understanding of what constitutes “conservation”. It will only succeed if the key drivers of biodiversity and ecosystem service loss are addressed in the whole planet. A broad, multifaceted and innovative approach, coupled with ambitious targets, provides our best hope yet of addressing complex conservation challenges.