Environmental problems such as climate change, loss of biodiversity, deforestation, air and water pollution, or the sealing of soils are urgent problems of humankind. They have been on the political agenda for many years but sustainable solutions and improvements are still missing in most areas. Many of these problems require technical solutions such as efficient ways to produce enough energy, housing, and food for an increasing world population. However, environmental problems are caused by humans, and it is only through a change of human behavior that they can be solved. These changes require that humans change the way they generate and use energy, substituting coal, oil, and gas by renewable energy sources. Moreover, adopting new technologies might not be enough but must go hand in hand with changes in lifestyle, reductions in consumption, reductions in mobility, and reductions in the use of land. The required changes will probably include all areas of life including our nutrition and how we grow food.