It can be seen that there are large number of parameters involved, interacting with each other in various heat transfer processes with the changing values of their properties with time; moreover, many of the parameters do not vary linearly, some of them change not only in magnitude but also in their sign – for example, aerosols and clouds. It is a crucial requirement that feedbacks from the various components, that is to say, the current values of the temperature of the earth and composition of the atmosphere, temperature and composition of the ocean water, forest and land characteristics . . . the various properties of the components. . . all need to be factored in the calculations.