1. What is the Cryosphere? – Part 1
Ice is part of the cryosphere. This includes glaciers, sea ice, snow caps, polar ice sheets,
permafrost, etc. Note all these components are the solid form of water, either permanently or
seasonally. An astonishing fact is that 90% of fresh water is locked in Antarctica which has a
tremendous area and volume compared to the Arctic. Since the cryosphere is such a large part of
Earth, yet a major source of uncertainty, it has major implications such as feedbacks and
properties to sustain life. Moreover, the components themselves are important.
Feedbacks are common in nature and are categorized as either positive or negative. Positive
feedbacks start with a change that eventually leads to a result that intensifies the initial change.
On the contrary, negative feedbacks slow down the initial change rather than strengthening it.
The most famous cryosphere feedback is the ice-albedo-feedback. As climate change increases
global temperatures, more ice will melt, the albedo will decrease, and temperatures will increase
again. Albedo is labeled as alpha and dictates the reflectivity of an object or body. Ice has an
albedo of around 0.8 which means it reflects 80% of solar radiation. Black bodies are perfect
absorbers which means they have an albedo of 1 since none is reflected. Anyway, the result of
the first round of the feedback cycle causes more ice to melt and continues the usual pattern.
A fundamental property of water is that ice is less dense; therefore, it will float just like an ice
cube in a glass of water. However, this is crucial since we know life survives underwater in
regions such as the Arctic. This allows for the existence of food chains and a thriving ecosystem.
Imagine a polar bear, the apex predator of the Arctic, not able to feed on prey. This would mean
the polar bear would have never even existed if it weren’t for the properties of water. Even more,
just think of how much water means to the planet.
Since 90% of the fresh water is in the Antarctic, then think of how important water resources are
for a growing population. Physical and economic water stress is pertinent in almost every
country and freshwater is critical to maintaining a functioning society since water is an
interdisciplinary issue that crosses politics, social issues, health care, and the environment. How
we get our water does depend on glaciers and snowfall which ultimately melts and provides a
steady supply for the United States in states such as the Sierra Nevada Mountains in California.
Note this is influenced by global warming and worsened by population stress. No matter the
perspective, water remains a vital part for human existence; therefore, more knowledge of the
cryosphere is required to understand impacts of sea level rise, water resources, and eventually
climate change which harms every aspect of the environment.