Effect of land-use change and methane mixing ratio on methane uptake from United Kingdom soil


T.W. Willison, fax +44-(0) 1582-760981


Methane (CH4) is a trace gas 30 times more radiatively active than carbon dioxide and, apart from a recent decrease, its atmospheric concentration has been increasing at a rate of ∼ 1%per annum since 1945. The increase results from an imbalance between CH4 production and consumption. Here we assess the impact that changes in land use and increasing atmospheric CH4 mixing ratios have had on CH4 uptake rates by soil in the UK since before the Iron age. This has been achieved by making retrospective analyses of CH4 uptake in UK soils under four different conditions of land use and CH4 mixing ratio. The calculations indicate that 54% of the current CH4 uptake by UK soils is the result of increased CH4 mixing ratio but that land-use change has caused a reduction of ∼ 37 kt CH4 y−1 in the potential sink strength of UK soils for CH4. The results are discussed with respect to the compilation of greenhouse gas inventories.