2017/08/27 by Adam Frank, Frank, Adam, Axel Kleidon +3 · 1 citation
Physics and Astronomy · #Earth and Planetary Astrophysics (astro-ph.EP) #FOS: Physical sciences #Space Science and Extraterrestrial Life
paper · pdf · doi:10.48550/arxiv.1708.08121
openalex publication_date 2017/08/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We develop a classification scheme for the evolutionary state of planets\nbased on the non-equilibrium thermodynamics of their coupled systems, including\nthe presence of a biosphere and the possibility of what we call an\nagency-dominated biosphere (i.e. an energy-intensive technological species).\nThe premise is that Earths entry into the Anthropocene represents what might be\nfrom an astrobiological perspective a predictable planetary transition. We\nexplore this problem from the perspective of the solar system and exoplanet\nstudies. Our classification discriminates planets by the forms of free energy\ngeneration driven from stellar forcing. We then explore how timescales for\nglobal evolutionary processes on Earth might be synchronized with ecological\ntransformations driven by increases in energy harvesting and its consequences\n(which might have reached a turning point with global urbanization). Finally,\nwe describe quantitatively the classification scheme based on the maintenance\nof chemical disequilibrium in the past and current Earth systems and on other\nworlds in the solar system. In this perspective, the beginning of the\nAnthropocene can be seen as the onset of the hybridization of the planet - a\ntransitional stage from one class of planetary systems interaction to another.\nFor Earth, this stage occurs as the effects of human civilization yield not\njust new evolutionary pressures, but new selected directions for novel\nplanetary ecosystem functions and their capacity to generate disequilibrium and\nenhance planetary dissipation.\n