"...We identify phosphate scarcity as the primary environmental control, suggesting that methane is released when phosphate-starved microbes break down organic compounds to meet their phosphorus needs. This process is most active in subtropical ocean regions, where >90% of the methane produced escapes to the atmosphere before it is oxidized. Future climate warming will intensify ocean stratification and phosphate scarcity, likely strengthening this natural methane source to the atmosphere and contributing to amplification of the warming trend."