Global Environmental Governance (GEG) has been a growing phenomenon since the middle of the 20th century, although the concept itself and its acronym are more recent and were in fact rarely used before 2000. The early interest in GEG was much preoccupied with environmental diplomacy and international legal agreements from the Stockholm UN conference 1972 onwards. The addition of the 'global' reflected the general rise in awareness of the significance of globalization since the 1980s. The further growth, and the transformation of GEG, in earnest since the Millennium has been increasingly marked by yet another category, 'the planetary', mirroring the increasing influence of Earth System Science on environmental and climate discourse. This has affected both GEG and 'the environment' itself. The conceptual shifts, including the rising interest in the Anthropocene, reflected profound changes in the human-Earth relationship. To analyze these shifts, which is the aim of this paper, I will use the 'Planetary Boundaries'-concept, launched in a highly cited paper in the journal Nature in 2009 and further developed in later publications, seminally in 2015 and 2023. I will consider the PB-concept, and versions of the often shown diagram that accompanied it, as both a case of 'planetary modelling' and, at the same time an 'environing technology' that is performative and shapes what the environment 'is' while modelling it. I also emphasize that the PB-model has led a 'social life', which has defined its continued evolution as a key agency in the formation of an Anthropocene Weltanschauung, with normative properties. I posit that the model helped shape the shift towards the epistemic and temporal 'environment' that has become mainstreamed in the UN Sustainable Development Goals and other goal setting projects.