Ban Ki-moon has journeyed to the Arctic Circle to see the devastating effects of global warmings.
The head of the UN has travelled to the Arctic Circle to see the effects of global warming.
Wolves have spread out in the Rocky Mountain states under federal protection, but could eventually face a deadly free-fire zone covering most of Wyoming.
From Maine to Georgia, scientists use desperate measures to stop invasive insects from destroying vital hemlock forests.
A rancher in Guatemala is restoring a rainforest, one seedling at a time.
Once a busy cargo transportation hub, the Gowanus Canal is now a contaminated waterway that neighboring residents and government authorities are determined to clean up and revive.