Did you hear that scientists say pink snow is coming – and it will not be pretty.
In 2016, some researchers from Europe were shocked to find glaciers which were covered with pink snow. Amazingly, this was caused by red algae with the redness increasing as the algae melts quicker than the white ice. Interestingly, this phenomenon was also observed half way across the globe in the state of Alaska. This pink snow is not a good thing and will be a serious problem for glaciers across the world. Scientists believe it is going to get much worse before it gets better.
This issue is a matter of simple science. Red-snow algae have been found all across the globe in alpine and polar settings. They get their unique color from a pigments class referred to as tetraterpenoids which are much darker than their white surrounding. When you group them together in packs, they tend to cause snowy areas to absorb much more energy from the sun and it melts faster. This is great for the algae as they thrive from the available nutrients in the melting water.
Researchers from Alaska Pacific University attempted to fill the experimental gap by creating an abundance of pink snow. They put water in experimental plots in Alaskan icefields and observed the growth rate of the algae to control plots that had received no water. In addition, they tossed bleach on a few plots as well.
They discovered that the red snow algae were both nutrient and water limited. The algae grew in abundance and increased fourfold when they received both vital ingredients. This melt meant that the more red algae there were the more snow would be melted. And plots that had been enriched were likely to produce three times as likely to melt away the snow as bleached plots.
After collecting the data that characterized the relationship between snowmelt and algae cover, the researchers employed satellite imagery in order to estimate red algae cover over a 730 square mile icefield. They observed that these microbes had reddened about 20% of the region.
“This study highlights the substantial impact of red-snow communities on glacier melt at high elevations and latitudes,” the researchers have written. “Because algae remain on the surface over much of the melt season and perennially resurface across melt seasons, they compound their effects over time.”
They also warn that a combo of climate change is driving the constant of ice and increased deposit of air borne particles. This includes the nutrient laden agriculture dust that will most likely provide a favorable environment for future formation of these red-snow algae. This will trigger additional melting that will result in a nasty feedback loop. This is a big concern as it could very well affect future sea levels.
Of course, this is just a single study that involved an experiment on a single ice sheet, so it’s impossible to know how big of a problem red snow algae will be for glaciers on a global scale compared with all of the other processes driving increased melt. Much more research will be needed to suss that out.
But, next time you read a story about sea level rise in Miami, know that tiny red microbes half a world might be conspiring to make things a tad worse.