EUA, also known as EU Allowance, are carbon credits traded in the EU ETS (Emission Trading Scheme). EUAs are emission allowances for stationary installations. One EUA gives the holder the right to emit one tonne of CO2. Once allocated among the EU ETS, EUAs can be traded through the carbon market.

EUAA, also known as European Union Aviation Allowance, are carbon credits traded in the EU ETS (Emission Trading Scheme). EUAAs are emission allowances for airline operators. One EUAA gives the holder the right to emit one tonne of CO2. Once allocated among the EU ETS, EUAs can be traded through the carbon market.

CERs, Certified Emission Reductions, are a type of emission units issued by the Clean Development Mechanism (CDM) Executive Board under the rules of the Kyoto Protocol. One CER offsets one tonne of CO2 compensation.