The world's human population is growing rapidly. Annually we may now move more earth than natural geological processes, and our dependence on fossil fuels is causing wholesale changes in climate and many ecosystem processes. Although human impacts on the globe have long had major consequences for the Earth's other inhabitants, the current combination of massive habitat change and rapid climate change poses an especially daunting challenge for many species. Rates of anthropogenic global change, from habitat alteration to modifications of the atmosphere, are so high that many species do not possess the capacity to “track” these changes through natural dispersal. In addition, “humanized” landscapes are now so pervasive in some parts of the globe that natural dispersal corridors have all but completely disappeared.