Specific Carbon Dioxide Emission
Specific Carbon Dioxide Emission means
"Carbon dioxide emissions related to ... another parameter"
The typical use of that term is the carbon dioxide (CO2) related to one unit of energy consumption e.g. electrical power.
Different primary energy types release different amounts of carbon dioxide to produce 1 kilowatt hour of power. Coal releases 500 to 900 grams CO2 for 1 kWh electrical power, natural gas 300 to 400 grams CO2 for 1 kWh electrical power. Renewable energies have much lower specific carbon dioxide emissions in the range of 20 to 100 grams CO2 for 1 kWh electrical power. In the case of renewables the CO2 emissions are not emitted during operation but during the production of the power plant components. E.g. steel or cement release carbon dioxide during chemical processes for their production.