The potential climate impact (radiative forcing) from peat extraction at different types of peatlands (with different land-use history) has been investigated. The climate impact considered emissions/uptake of carbon dioxide, methane and nitrous oxide before, during and after the peat extraction and combustion The four types investigated were: 1. Pristine mires 2. Organic agricultural soils 3. Drained forests and 4. Abandoned harvesting area subjected to previous peat extraction. Two types of after-treatments were used in the scenarios: rewetting or afforestation. The climate impact of the use of energy peat in Sweden was estimated based on description of mire type and former land-use of the peat-harvesting areas. The result show that the climate impact of current Swedish use of energy peat will give a smaller climate impact than the use of coal but a larger impact than the use of natural gas. It also shows that there is a potential of reducing the climate impact from peat utilisation by choosing extraction area and aftertreatment methodology.