Alkaline fuel cells (AFCs) are promising power sources due to superior kinetics and the ability to use inexpensive non-noble metal catalysts. However, carbonate formation from carbon dioxide in air has long been considered a significant hurdle for liquid electrolyte-based AFC technologies. Carbonate formation consumes hydroxyl anions, which leads to (i) reduced electrode performance if formed salts precipitate from solution and (ii) lowered electrolyte conductivity, which reduces cell performance and operating lifetime. Here, using a flowing electrolyte-based microfluidic fuel cell, we demonstrate that AFC performance can be resilient to a broad range of carbonate concentrations. Furthermore, we investigate the effects of carbonate formation rates on projected AFC operational lifetime. Results from this study will aid in the design of AFC-based power sources in light of the tradeoffs between performance, durability and cost.