Pink snow might sound outlandish, but it can actually be found around the world. While it may be pretty, it turns out it really isn’t a good look: the color is caused by blooming algae, which cause the snow to melt quicker. As the climate changes, these algae thrive – but their presence has ominous implications for glaciers.
In a study published this week in Nature Communications, scientists from the UK and Germany scrutinized the algae and an effect called “bio-albedo.” White surfaces, like glaciers and snow, reflect sunlight, and that’s called albedo. When those glaciers and snow melt, they reveal darker surfaces beneath, like mountains or oceans, and those surfaces have a lower albedo, or absorb greater amounts of sunlight. That effect is important because red algae actually gives snow a lower albedo and makes it melt faster.
Lead author Stefanie Lutz told Gizmodo, “The algae need liquid water in order to bloom. Therefore the melting of snow and ice surfaces controls the abundance of the algae. The more melting, the more algae. With temperatures rising globally, the snow algae phenomenon will likely also increase leading to an even higher bio-albedo effect.”
Lutz’s study reveals “red pigmented snow algal blooms” can decrease snow albedo by 13 percent during a melt season. The phenomenon takes place all around the world, too, from the Arctic to Antarctica. Greenland, the European Alps, and Iceland are a few other places where people have noted the algae. The algae is especially prevalent in the Arctic during the summer, when Lutz says by her estimation at least 50 percent of snow on a glacier displays the blooms.
Lutz and her colleagues recommended the algae be taken into account in future climate models, because warmer temperatures will likely mean more algae, and therefore even more melting.