Luke Griswold-Tergis, Executive Director of the Alaska Future Ecology Institute (AFEI) and director of the documentary Pleistocene Park, has spent over a decade working on one of the most provocative climate ideas: that reintroducing herds of large grazing animals to the Arctic could reduce global temperature by as much as ~0.5 °C by reducing permafrost thaw, increasing soil carbon, and preserving albedo. In this session, Griswold-Tergis explains the science behind large-herbivore rewilding, describe an ambitious new field trial to resolve key uncertainties, and discuss the ecological, logistical, geopolitical, and Indigenous partnership questions involved in moving this idea forward.