Global environmental cooperation does not occur in a vacuum. It is initiated, encouraged, coordinated, strengthened and monitored by a series of intergovernmental organizations (IGOs), with exclusive or partial environmental mandates. The environment as an issue for global governance organizations appeared on the international agenda in the late 1960s. Despite its relatively recent entry, the intersection between environment and development has gone on to become a central focus of global governance ever since, and IGOs have played a critical role in this process.