Global inequality in built-up land per capita and its change trajectories between 1985 and 2020

Built-up land has increased rapidly in recent decades, thus aggravating the competition for land between multiple uses. The increase in urban land can be decomposed into changes in population and changes in built-up land per person. Yet, it is unclear how this decomposition differs by country and how this decomposition changes over time. Moreover, we don’t know whether these changes affect the inequality in built-up land per capita. Here, we analyze the global distribution of built-up land per capita in the year 2020, as well as the changes therein between 1985 and 2020. We find that built-up land per capita in 2020 differs by an order of magnitude between countries, ranging from 15 m² per person in Ethiopia to 734 m² per person in Australia. Moreover, we find a wide range of different change trajectories, including both increases and decreases in built-up land per capita and in total population. As the total area of urban land increased in all countries, decreases in urban land consumption reflect a situation where the population increases faster than the total amount of urban land. We also find a large inequality in urban land consumption across countries, as indicated by a Gini index of 0.47 in 1985, decreasing only slightly to 0.45 in 2020. These findings suggest the need for a regionally differentiated approach to reduce urban land take, focusing first on mitigating further increases in those countries that already have a high urban land consumption.