I mean, decomposition releases methane over time, slower than burning does, but buried wood in the desert is more likely to petrify than rot. There’s a lot to be said for burying wood in certain situations. Hugelkultur (making agricultural/garden mounds out of wood and soil) if done right can do amazing things (everything from creating microclimates that increase biodiversity to supercharging the soil with beneficial fungi/bacteria, to increasing water retention).