How close are we to actually resurrecting the woolly mammoth? And what implications could this ability have for the future? Four thousand years after their extinction, the woolly mammoth looks primed to make a comeback, in the form of an elephant-mammoth hybrid. Their return could be more than just a technological marvel -- it could help preserve the permafrost and contain a greenhouse gas catastrophe. If de-extinction technologies live up to their promise, the rest of the 21st century is going to look very interesting -- and in some places, look more like the ancient past. This video was developed as a part of Engineering Earth, but warranted its own standalone spinoff video after I developed a particular fascination with this possibility and the recent breakthroughs being made in this field.