Never before have we known so much about how human behaviour impacts the environment. The resulting global warming leads to resource shortages and loss of habitat. Yet we seem to do little. Despair, denial and disengagement significantly inhibit action taking at all levels. This thesis focuses on empowering positive engagement, starting with individuals and households in Switzerland. A strategic design approach, involving research into the psychological and cognitive mechanisms behind denial led to the HEAT Method (Hope, Evaluate, Act, Tell), which focuses on emotional and motivational aspects and designs a positive future vision, a set of concrete actions and a corresponding narrative. Sharing the narrative openly is used to start a grassroots movement. Approaches for scaling up to society at large are also investigated.