Stefano Mancuso Cristiana Favretto Antonio Girardi

摘要

In the movie Silent Running (1972) we discover a future world where the built environment has completely replaced the natural. Plants have been eliminated from the planet and the last surviving specimens are kept in three huge geodesic greenhouses in space orbit. In reality, the scenario imagined is impossible. Animal life could never exist on a planet without plants. As the Russian botanist Kliment Timirya-zev wrote in the late 19th century, plants are the link between the Sun's energy and that of Earth. Without photosynthesis, solar energy could never be transformed into chemical energy, namely sugars - the main fuel of living organisms - and no oxygen would be produced. In many ways, plant activities complement those of animals. Plants are able to break down and use as nutrients most of the waste substances that animals produce -the CO_2 and pollutants generatedby any biological or productive activity.