As the world warms from human-emitted greenhouse gases during this century, one-quarter of all living things could disappear,

To help animals survive climate change, setting aside nature reserves isn't enough: to flee habitats made inhospitable by shifting climes, they also need "corridors" between wilderness areas.

This means preserving tracts of wilderness large enough to establish healthy populations. And it means establishing "biological corridors" between wilderness areas

Groups around the world are working to establish these wildlife highways, with varying degrees of success.

That's why some advocate "assisted migration," moving plants and animals before the climate changes too much.

Except for corridors and reserves, these measure are not sustainable or cost-effective in the long term,

The real solution is the most obvious,

stop and eventually reverse greenhouse-gas buildup from human activity.