Land use changes in Slovakia can help reduce CO2 emissions by increasing carbon storage in forests and producing biomass for bioenergy. Reforestation and forest plantations on marginal land could sequester up to 10% of national CO2 emissions. Using biomass for bioenergy could cover 64% of renewable energy needs, with potential for 6% on lower quality land. It is important to integrate biophysical and economic models to plan carbon sequestration activities and involve stakeholders in decision-making for effective climate change mitigation.