Development of a Land Cover Database Suitable for Estimating Current and Future Methane Emissions from Northern Boreal and Tundra Regions.
Abstract
Direct measurements of methane fluxes from wetland, lake, river, forest, and tundra ecosystems within the northern circumpolar region have been made since the 1970s, yet there are still major uncertainties with regards to both the magnitude and sensitivity of the overall emissions from the region. Given the rate of climate change at high latitudes and the potential impact of permafrost thaw, this uncertainty has implications for our projections of future atmospheric methane concentrations. One key source of uncertainty for estimating northern methane emissions is the lack of a suitable land cover database. No current circumpolar land cover database includes and differentiates between various open water and wetland ecosystems, which is necessary in order to avoid double accounting of emissions and to avoid extrapolation-bias from field measurements. Here, we present the development of a 0.5˚ gridded land cover model for the northern boreal and tundra biomes which includes fractional coverage of several vegetated wetland and open water classes that are known to have distinct magnitudes or seasonal patterns of methane emissions. This land cover database is based on an expert assessment, and uses information from currently available spatial data on climate, topography, soils, lake inventories, inundation extent, river inventories, permafrost zones, biomes, and global land cover data bases. The resulting land cover database was evaluated against regional, high-resolution maps of wetlands or lakes, and will be used in combination with methane-flux inventories that have similar ecosystem stratification in order to yield new regional estimates of methane emissions and their sensitivities to future climate change.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.B22D..01O
- Keywords:
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- 0428 Carbon cycling;
- BIOGEOSCIENCESDE: 0475 Permafrost;
- cryosphere;
- and high-latitude processes;
- BIOGEOSCIENCESDE: 0702 Permafrost;
- CRYOSPHEREDE: 1615 Biogeochemical cycles;
- processes;
- and modeling;
- GLOBAL CHANGE