Volume 10 (2012) Article 8

The potential peatland extent and carbon sink in Sweden, as related to the Peatland / Ice Age Hypothesis

by L.G. Franzén, F. Lindberg, V. Viklander & A. Walther

Published online: 17.09.2012

Summary

Peatlands cover approximately 65,600 km² (16 %) of the Swedish land area. The available areas suitable for peatland expansion are far from occupied after ca. 12,000 years of the present interglacial. We estimate the potential extent of peatland in Sweden, based on slope properties of possible areas excluding lakes and glaciofluvial deposits. We assume no human presence or anthropic effects, so the calculation is speculative. It may have been relevant for previous interglacials. We calculate the potential final area of peatlands in three scenarios where they cover all available land with different maximum slope angles (1?3 º) using a Digital Elevation Model (DEM). The three scenarios yield potential peatland areas of 95,663 km² (21 % of total available area), 168,287 km² (38 %) and 222,141 km² (50 %). The relative increases from the present 65,600 km² are 46, 157 and 239 % respectively. The slope scenarios give CO₂ uptake rates of 8.9?10.8, 18.1?22.4 and 24.6?30.5 Mt yr^-1. Under global warming conditions with isotherms moved northwards and to higher altitudes, following an increase of raised bog area, the CO₂ uptake rates might increase to 12.2?13.8, 24.4?27.7 and 33.5?37.9 Mt yr^-1; i.e. up to 4.3?4.9 vpb of atmospheric CO₂. If we make the speculative extrapolation from Sweden to all high latitude peatlands, and assume that all suitable areas with slope angle ? 3 ° become occupied, the global peatland CO₂ sink might approach 3.7 Gt yr^-1 (about 2 vpm yr^-1 and potentially cause a net radiative cooling approaching 5 W m^?2.

Citation

Franzén, L.G., Lindberg, F., Viklander, V. & Walther, A. (2012): The potential peatland extent and carbon sink in Sweden, as related to the Peatland / Ice Age Hypothesis. Mires and Peat 10: Art. 8. (Online: http://www.mires-and-peat.net/pages/volumes/map10/map1008.php)

Reviewers

IMCG and IPS acknowledge the work of the reviewers.