A sun-blocking global catastrophic risk (GCR) such as a nuclear winter could completely collapse the agricultural system. Producing alternative foods through methods requiring little to no sunlight has been identified as a cost-effective response to these types of GCRs. This preliminary techno-economic assessment evaluates the potential of acetic acid (AA) derived from carbon dioxide (CO2) via microbial electrosynthesis (MES) as an alternative food source for GCRs. Production and retail costs are estimated using net present value analyses for catastrophe and non-catastrophe scenarios. Based on nonstop (24/7) facility construction, the speed of food production ramp-up is estimated from capital expenditures using a reference class forecasting correlation. Potential production bottlenecks are assessed via a global resource requirement analysis. In regular conditions, the production cost of AA produced via MES is estimated at 1.83–5.20/kg (dry). MES production ramp-up is expected to fulfill less than 1% of global human caloric requirements by the end of the first year after the catastrophe. The retail cost of AA produced via MES in catastrophe conditions is estimated at 6–15/kg (dry). Potential bottlenecks to ramp-up include high electricity use and platinum dependency, which could be palliated via alternative processes based on gasification or bioelectrodes. AA from MES is not currently recommended as an alternative food for GCRs, because it is significantly more expensive and resource intensive than alternatives. Future research may change this, and could perhaps even enable MES as a sustainable food production method outside of catastrophes, given its potential for CO2 utilization.