Fig. 1: Observed and calculated growth rate in atmospheric methane.

In (a) the calculated growth rate in atmospheric methane due to different emission inventories (anthropogenic and biomass burning, see Method and Supplementary Fig. 1) from the box model are shown as coloured lines. The grey shading indicates the ranges in the calculated methane growth rate from the different emission inventories. In (b) the difference in the methane growth rate allowing for changes in methane lifetime (due to OH changes) over time compared to fixed methane lifetime. The green line shows contribution to the growth rate allowing for changes in methane lifetime following the OsloCTM3 CEDS21 + COVID, while the green shading indicates the range in contribution from allowing methane lifetime to change following the other OsloCTM3 CEDS17 simulations (with fixed and varying meteorology), CCMI and AerChemMIP results (see Box model section in Method). In (c) the difference in the methane growth rate allowing for changes over time in the natural emissions compared to fixed natural methane emissions. The different shadings indicate range in contributions from CLM driven by different meteorological data, CLM parameter sensitivity simulations, the set of VISIT model results and the set of LPJ-wsl simulations. In (d) the calculated methane growth rate combining different anthropogenic emission inventories, estimates of changes in methane lifetime over time and changes in natural methane emissions over time (red shading) compared to only the ranges in the calculated methane growth rate based on anthropogenic emission inventories (grey shading, similar to the shading in (a)). In all panels, the observed annual methane mole fraction increase from NOAA Global Monitoring Laboratory⁹ are shown in black. The stabilization period from 2000 to 2007 is indicated by the grey vertical field. In Supplementary Figs. 2–4, similar figures with different base set up of the box model (methane lifetime, natural emissions) are shown.