Mangroves are natural sources of methane (CH4) and nitrous oxide (N2O), the two primary GHGs besides CO2 (23, 24). Although carbon offsets would potentially need to net out non-CO2 emissions from protected mangroves, we find evidence that the discharges of CH4 and N2O would likely increase rather than decrease after land conversion (SI Appendix). Because mangrove protection would likely reduce emissions of non-CO2 GHGs relative to the alternative (baseline) land use, it is not necessary to reduce the volume of emissions offsets because of non-CO2 emissions.