The mechanisms that the “dormant microbial majority” use to remain energised in soil systems have long remained elusive. This talk will describe how atmospheric trace gases molecular hydrogen (H2) and carbon monoxide (CO) serve as alternative energy sources for dormant bacteria. Genetic and biochemical studies demonstrated that carbon-starved mycobacterial cells persist following carbon starvation by aerobically respiring these gases. Pure culture studies have shown that isolates of at least four dominant soil phyla, i.e. Actinobacteria, Acidobacteria, Chloroflexi, and Verrucomicrobia, can survive through equivalent mechanisms. A combination of genomic surveys and environmental studies suggest these processes are active in global surface soils. Atmospheric trace gases are particularly important for primary production in desert ecosystems. These findings in turn have implications for understanding microbial community structure, biogeochemical cycling, and bacterial dormancy.