Switzerland's glaciers on thin ice

We begin our journey one hour outside of Bern at the foot of the Trift glacier, where a lake has formed as a result of the melting ice. Since locals decided to build a suspended bridge to fill the gap in the missing glacier, the number of tourists has surged.

With more visitors, the nearby town of Gadmen has welcomed an unanticipated financial boost. Meanwhile, the region's largest hydropower company is investigating how the newly formed lake can be turned into a source of energy.

The Alps may have lost one third of their ice since 1950, but another of Europe's mountain ranges is also melting at a spectacular rate. Our next stop is the Pyrenees, where glaciers could disappear by the year 2050.

Finally, we focus on the earth's North and South Poles. Scientists fear global warming could release large quantities of methane trapped in the ice sheets of the Arctic and Antarctic. Methane is a harmful greenhouse gas, but also a potential source of energy.