The law of conservation of energy is well known from physics lessons: The energy of a closed system is constant. It is not lost, but is converted into other forms, for example when kinetic energy becomes heat – or vice versa, when heat leads to movement. However, this basic scientific principle often still poses a problem for climate research. Until now, for example, it has been unclear when calculating ocean currents where the energy that creates small-scale swirls and the mixing processes they cause come from. The same applies to the atmosphere, where air moves instead of water: Here, too, local turbulence can drive larger movements or, conversely, waves can break down into small structures on a larger scale.