A carbon credit is a generic term for any tradable certificate or permit representing the right to emit one tonne carbon di oxide or the mass of another greenhouse gas with a carbon-di-oxide element (tCO2e) equivalent of one tonne of carbon di oxide. Carbon credit is also often called as carbon offset. Carbon credits are associated with either removing$CO_2$ or$CO_2$ emissions from the atmospherein the case of carbon sequestration from forests and planting of trees or the reduction of future$CO_2$ emissions from renewable energy and energy efficiency projects that displace fossil fuel power generation production and industrial processes.