Inspired by cloud-to-ground lightning strikes on the early Earth, we designed a plasma (ionic gas) setup to mimic lightning-induced reactions, starting from simple and abundant reagents, such as N2 and CO2 in the air, inorganic minerals commonly found in rocks, and water. “Lightning”-type electrochemical reactions at air-water-ground interfaces lead to remarkable yields, with up to 40 moles of CO2 being reduced into CO and formic acid, and 3 moles of N2 being fixed into nitrate, nitrite and ammonia, per mole of transmitted electrons. Interfaces enable reactants (e.g., mineral particles and soluble electrolytes) to participate in radical and redox reactions, leading to higher yields compared to gas-phase only reactions, and faster kinetics compared to solution-only electrochemistry. Beyond exploring lightning and the chemical Origin of Life, this plasma electrochemical platform can contribute to green chemical synthesis, such turning air and water into nitrogen fertilizers and sanitizers with minimal carbon footprint.