Over the last century, greenhouse gas emissions have trapped energy in our atmosphere resulting in increased radiative forcing, and consequently, a warming climate. Methane (CH4) is a greenhouse gas characterized by its short atmospheric lifespan but high radiative forcing, making its reduction capable of greatly reducing climate change. Simple climate models (SCMs) project future climate change outcomes based on Earth system parameters, but their sensitivity to methane processes is poorly understood. SCM Hector models a global climate carbon cycle, reproducing historic climate trends, radiative forcing, and surface temperatures. In our research we worked with Hector’s four methane-related parameters, exploring Hector’s sensitivity and how methane parametric uncertainty affects future climate projections. Hector calculates atmospheric methane levels, and thus the strength of its radiative forcing, as the difference between new anthropogenic emissions and removal by various sources and sinks. Using a Monte Carlo approach, we generated normally distributed random parameter values and ran the model with these alterations, then evaluated its sensitivity to each parameter. Preindustrial emission levels were the most impactful methane parameter, followed by natural CH4 emissions. Stratospheric lifetime was the third most impactful, making up far less than the previous two, and soil lifetime contributed the least. Our findings indicate CH4 preindustrial and natural emissions affect atmospheric carbon outcomes greatly. They also highlighted that chemical process of methane, such assoil and stratospheric lifetime, could be improved.