The health of ecosystems and human health are closely linked. Interdisciplinary approaches and initiatives such as "One-Health," "EcoHealth," and, more recently, "Planetary Health" articulate this link. The three concepts are based on recognizing the interdependence between living organisms, both human and non-human, and their ecosystems. And yet, we are living in a time when human activity is leading to a profound degradation of the environment all over the world. Nine planetary boundaries for earth system processes have been proposed who's critical thresholds should not be crossed if we want to maintain our ecosystems and avoid risk of unwelcome outcomes: 1) climate change, 2) loss of biodiversity, 3) disturbances in biogeochemical cycles of nitrogen and phosphorus, 4) deforestation and changes in land use, 5) chemical pollution, 6) ocean acidification, 7) depletion of the ozone layer, 8) the degradation of drinking water, and 9) aerosol pollution. These "planetary bounderies" are suggested to represent a framework within which human activity can develop safely while still allowing the Earth systems to function sustainably. Yet several of these thresholds have already been crossed or are in a risky zone of uncertainty. This is all the more worrying because the connect ions between these various forms of environmental degradation and to human health are nonlinear and complex.