Our ancestors contemplated an inspiring night sky of science, philosophy, art … today, it is estimated that one third of the world’s population have never seen the Milky Way. The progressive degradation of the quality of the night sky due to an inappropriate use of the artificial light at night, as well to other sources of sky pollution, must be considered as the fundamental loss of a scientific, cultural and environmental heritage of humanity.

In this public talk we summarized the most relevant aspects of light pollution, the reasons for promoting good lighting to protect dark skies, and some of the initiatives at a global level that are being developed to preserve the darkness of the night sky.