Due to the growing interest in hydrogen (H₂) energy for climate change mitigation, hydrogen losses to the atmosphere are expected to increase the H₂ atmospheric concentration over its natural value. The problem is that, for its capacity to interact with atmospheric gases such as methane, ozone and stratospheric water vapor, hydrogen is an indirect greenhouse gas. Hence, a challenging question for the scientific community is: will the use of hydrogen-based energy be a real step toward the solution of climate change or will it effectively add to this already fundamental global issue? To answer this question, a critical piece of the puzzle has to be considered: bacteria in soils.