Deep sea mining is rapidly becoming technologically feasible, but it poses profound and potentially irreversible risks to fragile deep ocean ecosystems, climate regulation, and undiscovered biodiversity. While proponents argue it could supply critical minerals for the energy transition, scientific consensus warns that the environmental and ethical costs far outweigh current benefits, especially given uncertain long-term impacts and weak governance. A precautionary global moratorium, stronger regulations, and prioritizing recycling and alternative technologies are necessary before proceeding with any large-scale exploitation of the deep sea.