B3LYP and CCSD(T) calculations with various basis sets show that the Sc+CO 2 ->ScO+CO reaction can proceed by two distinct pathways, Sc+CO 2 ->(η 1 -O)ScOCO->(η 2 -O,O)cyc-ScCO 2 ->ScO+CO->end-/side-OScCO with the largest barrier of 3.2 kcal/mol and barrier-less Sc+CO 2 ->(η 2 -C,O)(ScOC)O->end-OScCO->ScO+CO. The `end-on' OScCO complex bound by 7.2 kcal/mol relative to ScO+CO is predicted to be the dominant reaction product. The reaction is more than 30 kcal/mol exothermic and the Sc atom is expected to be efficient in reforming CO 2 to carbon monoxide.