Through reading Latour’s concept of the Terrestrial and Arendt’s concept of storytelling through one another, this article develops a terrestrial ethics for sustainability. This ethics is furthermore developed through reflecting on the work of The Marine Education Center in Malmö with sustaining Öresund, especially its visions of transforming this strait between Copenhagen and Malmö into a biosphere area. It is argued how the Terrestrial is a new location developed from the Gaia hypothesis. It implies that life on earth is inseparable from all other organisms living in the thin layer of matter on top of the earth. An implication of the Terrestrial is the focus on pre-human Gaian stories through which humans are Grounded in the processes and conditions of life. This radical move implies not only an unconditional focus on the stories of land, water, soil, flora and fauna before we begin to talk about their functional utility. It is also grounded in the belief that we do not and cannot control the processes of life. Being terrestrials can create another ground of humanity in managing. This ground implies tending to Gaia’s multispecies stories in the ways we make our stories. A terrestrial ethics is based on the curiosity, care and compassion for multiple lives that are not understood in terms of how they connect and relate to human stories. Such positioning can serve as a ground for a new humanity in managing.