In some high mountain peaks in the US, in the shimmering snow powders an odd spectacle can startle an unsuspecting beholder — patches of pink. What is this? Perhaps the blood of some animal? Not really.
This is a phenomenon caused by the blooming of a green algae known as Chlamydomonas nivalis, according to an article in the Smithsonian magazine. And it is a cause for concern, because the algae’s presence increases snowmelt.
Bright white snow has a high albedo — it reflects back sunlight. But when the algae bloom and turn red, they absorb more light, and heat up. This causes the snow to melt. The algae, which love water, then eat more nutrients and multiply, adding to the problem.
The higher algal growth these days has been attributed to climate change.
The western US is facing its worst drought in more than 1,200 years, which has been exacerbated by climate change, says the article.
Researchers are still unsure why the algal blooms are occurring, how exactly they’re impacting the snowmelt, and how climate change is contributing to the algae’s spread.
But for now, if you are up there in the mountains and chance upon the pink patches in white snow, leave the worrying to scientists and just enjoy the beauty of the sight.