Resumen
Some of the fundamental problems related to the current approach to global climate change from modelling and observational stand points are discussed. The author offers his personal opinion and suggests caution in terms of an all out effort to understand the problem through numerical modelling based on GCMs models. At the same time he advises other approaches i.e. statistical and other studies of atmospheric phenomena different from temperature in seeking evidences of climate change. He emphazises in particular the need to find, for political reasons and as soon as possible, a clear signal that the greenhouse gas affect is being enhanced and that this has an impact on the general circulation of the atmosphere.