The absence of significant detectable signatures of organic molecules in the atmosphere and on the surface of Mars is a major unsolved puzzle. One possible explanation is that perchlorate-rich Martian soils, activated by solar ultraviolet (UV) radiation, create an environment favorable for the rapid oxidation of organics such as alkanes (including methane or CH₄). In this paper, we measured product formation rates from the methane-perchlorate-UV system at room temperature. Our results show that magnesium perchlorate (Mg(ClO₄)₂•6H₂O) surfaces exposed to UV light at wavelengths reaching the Mars' surface accelerate the decomposition of methane (CH₄), resulting in the formation of carbon dioxide (CO₂), carbon monoxide (CO), and volatile chlorine oxides. The production rates for CO₂ and CO on UV-activated perchlorate surfaces are accelerated by a factor of 2.5 and 4.5, respectively, compared to those in the absence of perchlorate. In addition, with UV radiation exposure, perchlorate (ClO₄⁻) decomposes to chlorate (ClO₃⁻) and chlorine oxides. These results are incorporated into a simple box model to estimate the near-surface atmospheric methane lifetime. The model gives a lower bound of the lifetime on the order of hours to days, substantially shorter than ~300 yrs. calculated from methane loss by gas-phase chemistry alone.