Modeling regional to global CH4 emissions of boreal and arctic wetlands

Research output: Contribution to journalArticle

Abstract

Methane (CH4) emission from boreal, arctic and subarctic wetlands constitutes a potentially positive feedback to global climate warming. Many process-based models have been developed, but high uncertainties remain in estimating the amount of CH4 released from wetlands at the global scale. This study tries to improve estimates of CH4 emissions by up-scaling a wetland CH4 emission model, PEATLAND-VU, to the global scale with a spatial resolution of 0.5 degrees for the period 2001-2006. This up-scaling was based on the global circum-arctic distribution of wetlands with hydrological conditions being specified by a global hydrological model, PCR-GLOBWB. In addition to the daily hydrological output from PCR-GLOBWB, comprising water table depths and snow thickness, the parameterization included air temperature as obtained from the ECMWF Operational Archive. To establish the uncertainty in the representations of the circum-arctic distribution of wetlands on the CH4 emission, several existing products were used to aggregate the emissions. Using the description of potential peatlands from the FAO Digital Soil Map of the World and the representation of floodplains by PCR-GLOBWB, the average annual flux over the period 2001-2006 was estimated to be 78 Tg yr(-1). In comparison, the six-year average CH4 fluxes were 37.7, 89.4, 145.6, and 157.3 Tg yr(-1) for different estimates of wetland extends based on the studies by Matthews and Fung, Prigent et al., Lehner and Doll, and Kaplan, respectively. This study shows the feasibility to estimate interannual variations in CH4 emissions by coupling hydrological and CH4 emission process models. It highlights the importance of an adequate understanding of hydrology in quantifying the total emissions from northern hemispheric wetlands and shows how knowledge of the sub-grid variability in wetland extent helps to prescribe relevant hydrological conditions to the emission model as well as to identify the uncertainty associated with existing wetland distributions.

Details

Authors
  • A.M.R. Petrescu
  • L.P.H. van Beek
  • J. van Huissteden
  • C. Prigent
  • T. Sachs
  • C.A.R. Corradi
  • Frans-Jan Parmentier
  • A.J. Dolman
External organisations
  • Vrije Universiteit Amsterdam
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Geography

Keywords

  • METHANE EMISSIONS, NATURAL WETLANDS, ATMOSPHERIC METHANE, CARBON, CLIMATE, PARAMETERIZATION, SENSITIVITY, PERMAFROST, BUDGET, TUNDRA
Original languageEnglish
JournalGlobal Biogeochemical Cycles
Volume24
Issue number4
Publication statusPublished - 2010
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes