As we know, climate change is a global phenomenon that is leaving us with both worrying and surprising images. The fact that average global temperatures are constantly rising is causing some rather exceptional situations. Since Antarctica is one of the areas of the planet most impacted by the increase in global temperatures, it is here that we can see some of the most unusual phenomena. Today we're going to talk about one of the phenomena that is surprising the entire scientific community: green snow.
In this article we'll tell you what green snow means, what its characteristics are, and what consequences it has with respect to climate change.
What is green snow
The term "green snow" might immediately bring to mind the growth of vegetation due to melting Antarctic snow. Currently, however, rising global temperatures are causing the white snow to turn green as microscopic algae proliferate. This massive growth gives the snow a green hue, creating a bright, vibrant green appearance. This phenomenon is even visible from space and has allowed scientists to create a map of it.
All data is collected through satellites capable of observing and taking images. Observations taken over several summers in Antarctica have been combined with satellite observations to estimate all the areas where green snow will be present. All these measurements will be used to calculate the rate at which the algae will continue to spread across the continent due to climate change.
As expected, the growth of these microscopic algae will have repercussions on global climate dynamics.
Green snow and terrestrial albedo
The Earth's albedo is the amount of solar radiation reflected from the surface back into space by various elements. These elements include light-colored surfaces, clouds, gases, and so on. Snow can reflect up to 80% of the solar radiation that strikes it. What has been discovered about green snow is that its albedo is reduced to 45% . This allows more heat to be retained on the surface without being reflected back into space.
One might think that since the albedo in Antarctica is going to decrease, it will become a self-reinforcing driver of average temperatures. However, we must also consider the different factors that influence this temperature evolution. For example, the growth of microscopic algae also promotes the absorption of carbon dioxide through photosynthesis. This helps reduce the amount of greenhouse gases, which in turn helps prevent further temperature increases.
Therefore, we must analyze the balance between the amount of heat Antarctica can retain due to the decrease in Earth's albedo and the capacity of microscopic algae to absorb carbon dioxide from the atmosphere. As we know, carbon dioxide is a greenhouse gas capable of trapping heat. Therefore, the more carbon dioxide there is in the atmosphere, the more heat will be stored, and consequently, temperatures will rise.
Studies on microscopic algae in Antarctica
Numerous studies published in the journal Nature Communications already predict that green snow will continue to spread across the Antarctic continent. As climate change increases average global temperatures, we expect a further expansion of these algae.
The studies also show that Antarctica is experiencing the effects of climate change most rapidly. This warming is accelerating in this part of the planet. Data from the study shows that a heat wave was recorded in East Antarctica in January, bringing temperatures 7 degrees Celsius above average . As the warming process continues, the amount of microalgae will also increase.
The problem is that snow no longer lasts as long as it once did. We must also consider the rising sea levels that will cause the complete melting of the Antarctic ice. To better understand this, it's important to note that the main difference between Antarctica and the North Pole is that Antarctica has a landmass beneath its ice. This means that if the ice above the land melts, sea levels will rise. The opposite is true for the North Pole. The polar ice caps in the far north do not have a continent beneath them. Therefore, if this ice melts, it will not cause sea levels to rise.
The algae that have been studied in Antarctica are concentrated on the coast. This is because they are the areas that become warmer since they have average temperatures of just over zero degrees. The proliferation of microalgae is also promoted by mammalian animals and seabirds. And it is that the excrement of these animals are very nutritious for these photosynthetic organisms. That is, these same excrements serve as fertilizer and contribute to its growth.
A new CO2 sink
It is known from studies that most algal colonies are close to penguin colonies. They are located at the points where the few rest and in the vicinity of some places where the birds nest.
One positive aspect of all this is that a new CO2 sink will be created on the planet. Since algae maintain a high rate of photosynthesis, they generate their own energy and absorb this greenhouse gas during this process. Thanks to the growth of these algae, a greater amount of carbon dioxide will be extracted from the atmosphere, which could be considered a positive development. This new CO2 sink could absorb up to 479 tons annually . This figure could be even higher, as there are other types of algae, orange and red in color, that have not yet been included in the study.
We shouldn't think that all of this will be positive overall, since the consequences of climate change are so serious that this effect of green snow cannot be offset.
That with this information they can learn more about green snow and its importance.