For emissions trading where greenhouse gases are regulated, one emissions permit is considered equivalent to one metric ton of carbon dioxide (CO2) emissions. Other names for emissions permits are carbon credits, Kyoto units, assigned amount units, and Certified Emission Reduction units (CER). These permits can be sold privately or in the international market at the prevailing market price. These trade and settle internationally, and hence allow permits to be transferred between countries. Each international transfer is validated by the United Nations Framework Convention on Climate Change (UNFCCC). Each transfer of ownership within the European Union is additionally validated by the European Commission.