Hydroclimate and landscape diversity drive highly variable greenhouse gas emissions from tropical and subtropical inland waters

(Sub)tropical inland waters are important greenhouse gas (GHG) sources, yet limited observations have long hindered broad analyses of GHG variability across this diverse region. Here, through a meta-analysis, we have examined the rates and drivers of GHG emissions from flowing and standing (sub)tropical inland waters. We find considerable spatial variation in fluxes, largely related to differences in hydroclimate, geomorphology, land cover and human disturbance. Flowing waters emit more carbon dioxide (3,387_2,121^5,702 TgCO₂ yr⁻¹, expressing median_{first quartile}^{third quartile}), methane (10.6_0.1^28.8 TgCH₄ yr⁻¹) and nitrous oxide (0.62_0.35^1.10 TgN₂O yr⁻¹) than standing waters (114₇₃²¹⁹ TgCO₂ yr⁻¹, 5.4_2.1^9.1 TgCH₄ yr⁻¹ and 0.03_0.02^0.05 TgN₂O yr⁻¹, respectively). (Sub)tropical inland waters release 4,238₂₄₇₃⁷³⁷⁵ TgCO₂-equivalents annually, with first- to third-order streams contributing 75% of riverine emissions and lakes larger than 100 km² contributing 59% of standing water emissions. Our results suggest emissions from (sub)tropical waters are 29–72% lower than earlier estimates, a downward revision with important implications for global GHG budgets.