Over the past half century, the global environment has become subject to an accelerated pace of mediation and datafication. This ongoing transition has become so comprehensive that the knowledge, management and governance of the Earth system is dependent on enormous flows of data from a “vast machine” of measuring tools. These processes combined have formed what we call a “mediated planet,” subject to interpretation and shared human decision-making – that should ideally be democratic, inclusive and accountable. As environmental datafication continues to accelerate, private corporations are gaining increasing influence on and power over the associated collections of data. This is a cause for concern, as the global environmental commons are a public interest of concern to all people. This article argues for the need to critically research the challenges and risks associated with the rapid datafication of the environment, specifically in relation to the UN Sustainable Development Goals (SDGs) for climate change (13), the ocean (14), biodiversity (15) and inclusive and accountable institutions (16). More knowledge is needed of how the SDGs and their supporting networks influence data-generation on a mediated planet, and how issues of access to and use of environmental data, as well as data ownership and AI implementation, can best be navigated. We contend that such knowledge can help enhance the democratic potential of the SDGs to build public trust and secure broad participation in global environmental governance in ways that also support peaceful and inclusive societies, as promised by SDG 16.