'Snow blood': Why climate change may be turning the Alps red

High up in the Alps, vast patches of snow are mysteriously turning red in a phenomenon known as "snow blood". The result of a type of algae, the red patches are becoming increasingly common, say locals, and according to scientists are likely caused by climate change. They fear the algae could spell ecological disaster for this remote region as the red pigment reduces the snow's ability to reflect sunlight, causing it to melt faster.