Tropical peat swamp degradation can modify net peat greenhouse gas (GHG) emissions even without drainage. However, current Intergovernmental Panel on Climate Change (IPCC) guidelines do not provide default emission factors (EF) for anthropogenically-degraded undrained organic soils. We reviewed published field measurements of peat GHG fluxes in undrained undegraded and degraded peat swamp forests in Southeast Asia (SEA) and Latin America and the Caribbean (LAC). Degradation without drainage shifted the peat from a net CO₂ sink to a source in both SEA (− 2.9 ± 1.8 to 4.1 ± 2.0 Mg CO₂–C ha⁻¹ yr⁻¹) and LAC (− 4.3 ± 1.8 to 1.4 ± 2.2 Mg CO₂–C ha⁻¹ yr⁻¹). It raised peat CH₄ emissions (kg C ha⁻¹ yr⁻¹) in SEA (22.1 ± 13.6 to 32.7 ± 7.8) but decreased them in LAC (218.3 ± 54.2 to 165.0 ± 4.5). Degradation increased peat N₂O emissions (kg N ha⁻¹ yr⁻¹) in SEA forests (0.9 ± 0.5 to 4.8 ± 2.3) (limited N₂O data). It shifted peat from a net GHG sink to a source in SEA (− 7.9 ± 6.9 to 20.7 ± 7.4 Mg CO₂-equivalent ha⁻¹ yr⁻¹) and increased peat GHG emissions in LAC (9.8 ± 9.0 to 24.3 ± 8.2 Mg CO₂-equivalent ha⁻¹ yr⁻¹). The large observed increase in net peat GHG emissions in undrained degraded forests compared to undegraded conditions calls for their inclusion as a new class in the IPCC guidelines. As current default IPCC EF for tropical organic soils are based only on data collected in SEA ombrotrophic peatlands, expanded geographic representation and refinement of peat GHG EF by nutrient status are also needed.

即使没有排水，热带泥炭沼泽退化也会改变泥炭温室气体（GHG）净排放量。然而，当前的政府间气候变化专门委员会（IPCC）指南并未提供人为退化的不排水有机土壤的默认排放因子（EF）。我们回顾了东南亚（SEA）以及拉丁美洲和加勒比地区（LAC）不排水、未退化和退化泥炭沼泽森林中已发表的泥炭温室气体通量实地测量结果。不排水的退化使泥炭从净 CO _{2汇转移到 SEA（− 2.9 ± 1.8 至 4.1 ± 2.0 Mg CO 2} –C ha ⁻¹ yr ⁻¹）和 LAC（− 4.3 ± 1.8 至 1.4 ± 2.2）的来源Mg CO ₂ –C ha ^-1 yr ^-1 )。它增加了东南亚地区的泥炭CH ₄排放量（kg C ha ^-1 yr ^{-1 ）（22.1 ± 13.6 至32.7 ± 7.8），但减少了拉丁美洲和加勒比地区（218.3 ± 54.2 至165.0 ± 4.5）。}退化增加了SEA森林中泥炭N ₂ O排放量（kg N ha ^-1 yr ^{-1 ）（0.9 ± 0.5至4.8 ± 2.3）（有限的N} ₂ O数据）。它将泥炭从净温室气体汇转移到了东南亚的温室气体源（− 7.9 ± 6.9 至 20.7 ± 7.4 Mg CO ₂ -当量 ha ⁻¹ yr ⁻¹），并增加了拉丁美洲和加勒比地区的泥炭温室气体排放量（9.8 ± 9.0 至 24.3 ± 8.2 Mg CO ₂ -当量ha ^-1 yr ^-1 )。与未退化的条件相比，未排水的退化森林中观察到的泥炭温室气体净排放量大幅增加，要求将其作为一个新类别纳入 IPCC 指南。由于目前热带有机土壤的默认 IPCC EF 仅基于在 SEA 营养泥炭地收集的数据，因此还需要扩大地理代表性并按养分状况细化泥炭 GHG EF。