Drastically reducing greenhouse gas emissions to reach a post carbon society by 2050 requires policy makers - and to an important extent city authorities - to take action to change the way by which our modern society uses energy. Key sectors of the economy will be affected, but policies will work only if stakeholders actively participate and change their way of living, moving, consuming and doing business. Today’s climate objectives require policy-making tools which engage directly with citizens as co-creators of decisions. This paper discusses a living lab approach using visioning and backcasting with an example of results in stakeholder workshops in the cities of Barcelona and Malmö for the EU funded project POCACITO.