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

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.