As temperatures rise in the Andes, the glacier atop a mountain in Ecuador vanishes. Creeks are drying up. Lake levels are plummeting. The indigenous people are competing for shrinking supplies of water while they try to understand what is happening.
In Tanzania, the legendary snows of Kilimanjaro are in alarming retreat. There, as in Ecuador, farmers are struggling with the changing weather.
Rising seas represent one of the gravest threats of global warming. A quarter of the ice sheets in Antarctica and Greenland could melt by the end of the century. Residents of Kiribati, a string of islands between Hawaii and Australia, say they're already noticing changes.
Some pacific islanders are leaving their homes already. Islanders from one of the world's smallest nations, Tuvalu, struggle to retain their island culture in a modern environment.
The effects of rising seas may be even more catastrophic in densely populated South Asia, where tens of millions of people live in low-lying deltas. In Bangladesh, people are accustomed to coping with natural disasters. But this one could be different.
In northwestern Tanzania, generations of fishermen have lighted the nights with kerosene lamps. But now Lake Tanganyika is warming, and some signs indicate that a tiny sardine known as dagaa may be in decline. It's a fish millions of people depend on for protein.
Diminished polar ice is forcing the town of Churchill in Upper Manitoba, Canada, to reexamine whether it has any future as "The Polar Bear Capital of the World."