In recent years, it has proven increasingly difficult to persuade states to adopt new environmental commitments and to comply with their obligations already agreed upon under international environmental law. This begs the question how international environmental law could gain new momentum. This article suggests that a stronger emphasis on the health aspects of environmental problems could drive the international community to better respond to environmental problems. Such a shift of perspective could best be illustrated at the international level if the World Health Organization (WHO) takes on environmental issues. Therefore, this article analyses, by example of the global waste challenge, the WHO's Constitution and the International Health Regulations (2005) to determine its potential and limitations as an actor in international environmental law. The article argues that the WHO should use the ongoing COVID-19 pandemic to step up its commitment towards the environment, strengthen the 'One Health' approach and thereby help international environmental law regain momentum.