Greenhouse gas emissions from managed peat soils: is the IPCC reporting guidance realistic?

Drainage of peatlands leads to the decomposition of peat, resulting in substantial losses of carbon and nitrogen to the atmosphere. The conservation and restoration of peatlands can provide a major contribution to the mitigation of climate change. Improvements to guidance and capacity for reporting of greenhouse gas emissions from peatlands will be valuable in the context of the current negotiations towards a post-2012 climate agreement. This article evaluates IPCC approaches to greenhouse gas emissions from managed organic (peat) soils and presents a summary table comparing IPCC default values with best estimates based on recent literature. Inconsistencies are pointed out with regard to the IPCC definitions of organic soils and climate zones. The 2006 IPCC Guidelines use a definition of organic soil that is not totally consistent with FAO definitions, use climate zones that are not fully compatible, present default CO2 values that are substantially (often an order of magnitude) too low, and present a default N2O value for tropical cropland that is also an order of magnitude too low. An update of IPCC default values is desirable. The IPCC Emission Factor Database offers a platform for establishing more accurate emission factors, but so far contains little information about emissions from peat soils.