The Global Environment Facility (GEF) provides support to address global environmental concerns related to biodiversity, climate change, international waters, land degradation, chemicals and waste, the ozone layer, and persistent organic pollutants. Since its inception in 1991, the GEF has provided developing countries and countries with economies in transition USD 23 billion in grants and mobilized more than USD 129 billion in co-financing. These grants are implemented through a network of 18 accredited agencies (GEF Agencies).