In this paper we make an empirical approach with the objective of measuring, in a certain moment of time, the relative share of the inhabitants of different parts of the world in the appropriation of the environmental space in relation to the CO2 absorption capacity and of analysing the posterior dynamics of overuse of this space. The exercise takes into account the very unequal distribution of emissions in a base year (1972) and it compares the emissions evolution during 1972-1995 for several territorial areas. It measures the two factors which explain this evolution: demographic growth and per capita emissions dynamics. The total emissions variation for the different areas is compared with the "justified" variation. This "justified" variation is defined as the rate at which any region should change its emissions in order to place these in 1995 at the 1972 world level considering an equal use of the environmental space in that year. The conclusion is that OECD countries - and also former communist bloc- maintained and in many cases clearly increased their excessive occupation of environmental space. In other areas - as China, other Asiatic countries and Africa - emissions increased very much but they rose less than the "justified level" as previously defined.