Climate change seems to be a reality we are all living through. However, agreeing on policies to mitigate a global catastrophe is a different and unsuccessful story. Even when TRIPS flexibilities in principle will allow the protection of public health-climate related concerns, to what extent countries part of investment treaties will be able to make use of such flexibilities, for the sake of climate change. The chapter establishes the links between public health and climate change. Then analyses how public health has been “defined” through investment, and concludes with the challenges posed to countries’ policy space to define and amend national laws about climate change, if the latter does not fall within the scope of an investment defined “public health concern”.