Figure 4.

(a) Linear regression of mean annual global fossil fuel emissions log (Tg C yr⁻¹) as a predictor of global biomass burning emissions log (Tg C yr⁻¹) from 1997 to 2010; (b) linear regression of mean annual fossil fuel emissions log (Tg C yr⁻¹) as a predictor of biomass burning emissions log (Tg C yr⁻¹) by land cover (lcode; 1997–2010); shading indicates a Loess smoothing function. Because the area of the grid cells changes with latitude, emissions per grid cell were multiplied by the area (m²) that each grid cell occupies on the ground (See table 3 for definitions of land cover type codes.).