Human-assisted migration is a solution that some people find scary. It pits our desire to prevent extinctions against deep-rooted values of preserving ecosystems in their native state. And it involves a level of human meddling that some have called hubris. But the big picture is more complicated than that. If predictions are right, then climate change over the next 200 years will make anything that a few wayward naturalists do look tame. It will melt away biological communities that we know today, shuffling the deck of surviving species into new ecosystems.