**Abstract**

Present day status of planet earth is perilous. In January 2023, the "Doomsday Clock" (a serving global indicator for worldwide catastrophe) crept up to 90 seconds before midnight. According to the bulletin of atomic scientists, the Doomsday Clock aims to designate humanity's closeness to annihilation; with midnight being the instance of ignition and thus, the point of no return from Armageddon. Because 90 seconds is the closest the clock has ever been to midnight, the year 2023 is therefore, planet earth's nearest to Armageddon. But why is planet earth perilously close to extinction? The bulletin of atomic scientists cited threats from War; Disease; Climate change; and Disruptive technologies as major contributors. In the context of climate change mitigation, this chapter attempts to present contributions of the circular bioeconomy paradigm that could help humanity to dial back the Doomsday Clock. Anaerobic digestion (AD), integrated regenerative agriculture (IRA), controlled ecological life support system (CELSS), bioregenerative life support system (BLSS), note by note cuisine (NNC), circularity, and molecular pharming are some of the solutions isolated.

**Keywords:** aerosols, anaerobic digestion, biofertilizer, biofuels, biogas, circular bioeconomy, climate change, digestate, doomsday clock, ecological intensification, extreme weather events, greenhouse gases, particulate matter, regenerative agriculture, regolith, renewable energy, space food system, sustainability
