State of practice of cumulative effects assessment and management: the good, the bad and the ugly

The historical, current and future international practice of cumulative effects assessment and management (CEAM) is addressed. The 'context' of CEAM is explained and challenges from scientific and policy issues and numerous uncertainties are described. A six-step generic process for carrying out CEAM is provided. Opportunities for mitigation and management are highlighted, with emphasis given to 'collaboration' as a foundational element for dealing with cumulative effects. This state-of-practice review concludes by noting six 'ugly lessons' which result from lack of appropriate attention, eight 'bad lessons' which reflect practices that need improvement, and 12 'good lessons' which can be used to articulate good practice principles related to CEAM. In many situations some modification of EIA methods and tools may be necessary. In summary, the practice of CEAM is growing out of its infancy. As experience is accrued, it is anticipated that good practice principles will be further articulated and utilized on an international basis.