An LCA-based approach to integrate drained peatland emissions into the carbon footprint of dairy production: a case study from the pre-alpine region of Southern Germany

Abstract

Purpose Current life cycle assessments (LCAs) of milk production often underestimate environmental impacts by overlooking significant greenhouse gas (GHG) emissions from drained peatlands. This study applied a novel approach to quantify the contribution of GHG emissions from drained peat soils to the carbon footprint (CF) of milk production in German pre-alpine dairy farms, addressing this critical knowledge gap. Methods Carbon footprints (CFs) of milk production were calculated for three distinct dairy farms in Southern Germany, both with and without the inclusion of peatland emissions. Three methodological approaches were applied for emission quantification: (i) IPCC Tier 1, (ii) implied emission factors (EFs) from German national inventory reporting, and (iii) water table depth (WTD)-dependent response functions. A near-natural peatland reference scenario was also developed for contextualization. Results and discussion Results reveal that peatland emissions are a highly significant contributor, more than doubling average milk CFs at farm-level. A positive correlation was found between the extent of drained peatland area and carbon emissions, with the CF from drained peat soils being 3 to 6.5 times higher than those from mineral soils if the entire farm area was located on drained peat soil (i.e., 'under full peatland drainage’). The chosen methodology significantly influenced CFs, where WTD-dependent approaches consistently yielded higher GHG estimates. Conclusions These findings underscore the crucial importance of incorporating peatland emissions into dairy LCA studies for accurate environmental assessments. They highlight the urgent need for targeted mitigation strategies, especially water table (WT) management, to effectively reduce agriculture’s climate impact. Recommendations Future research and policy should prioritize developing and implementing effective WT management techniques. Encouraging the integration of peatland emission data into standard agricultural LCA methodologies is also vital to generate realistic and complete and to drive sustainable practices.

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