The above example focused on the economic impacts of the exploitation of energy. A similar scenario plays out in nature and biology, where living organisms can extract energy of varying quality from nature, ultimately driven by solar energy as the primary driver of thermodynamic disequilibrium on Earth. The ecological balance of ecosystems is predicated on the energy flows through the system. For example, rainwater drives the erosion of rocks, which liberates chemicals that can be used as nutrients; these are taken up by plankton, using solar energy to grow and thrive; whales obtain energy by eating plankton, thus indirectly using solar energy as well, but this time in a much more concentrated and higher quality form.