Disasters undermine development and jeopardise the achievement of the Millennium Development Goals (MDGs). Evidence has long suggested that disaster risk reduction (DRR) has a high cost-benefit ratio. The UN’s International Strategy for Disaster Reduction (ISDR) defines DRR as: "Actions taken to reduce the risk of disasters and the adverse impacts of natural hazards, through systematic efforts to analyse and manage the causes of disasters, including through avoidance of hazards, reduced social and economic vulnerability to hazards, and improved preparedness for adverse events".