Contributions to sustainable socio-economic, ecological and institutional development associated with a project and which go beyond the reduction of greenhouse gas (GHG) emissions. Co-benefits are mostly reflected in the respective sector policy and can be obtained at a regional or local level (e.g. increase in income, social security, reduction of airborne pollutants). Sustainable development co-benefits are considered a key element to create country ownership and a driver for transformational change. They thus can have an important impact on the long-term sustainability of a project.