This technical paper examines the costs of meeting explicit targets for increments of carbon sequestered in forests when both forest management decisions and the area of forests can be varied. Costs are estimated as welfare losses in markets for forest and agricultural products. Results show greatest change in management actions when targets require large near-term flux increments, while land area change is largest when long-term increments are needed. Marginal costs per tonne of carbon flux do not vary greatly with the form of the target and are similar to findings of earlier studies for comparable size of average carbon flux increment.