Entropy as a Criterion for Sustainability—CO₂ Removal and Storage or Utilization (CCS, CCU) Are Not Sustainable

The principles of nonequilibrium thermodynamics are briefly discussed, with a focus on entropy. For the first time, the energy consumption and entropy production of CO2 final storage and utilization (CCS and CCU) are quantitatively analyzed and interpreted. This shows that the final storage and chemical utilization of CO2 are not sustainable processes for solving the climate crisis. Building on this, a new proposal for a quantitative criterion for sustainability is presented: entropy. In addition, a relatively simple indicator is presented that is a helpful (and easier to calculate) indicator for the entropy production of various processes or products.