A model for the influence of the greenhouse effect on insect and microorganism geographical distribution and population dynamics using cellular automata is presented. Based on this model, an algorithm has been developed and used to determine the geographical distribution and population dynamics of a hypothetical species in an scenario of global warming. The species' initial population distribution is assumed to be Gaussian. After the initiation of global warming, the population moves and after a few decades the population distribution is no longer Gaussian. Larger populations are found in the direction of population movement.