The notion of cryosphere is not part of the dictionary prepared by the Royal Spanish Academy ( RAE ). The concept, in any case, is usually used with reference to the surface water of our planet that is in a solid state due to low temperatures.
The cryosphere, in this framework, is made up of the Earth 's large masses of ice and snow . Therefore we can find the cryosphere in Antarctica and the North Pole , among many other regions, such as Greenland, Northern Siberia, the Arctic Ocean and Northern Canada and most of the peaks of the highest mountain ranges. of the world.
When the cryosphere is caused by the freezing of the oceans , it does not affect sea level, since solid water is formed from it. On the other hand, if glaciers melt, they do cause a rise in sea level. Global warming, which affects the cryosphere and causes glaciers to melt, is therefore causing sea levels to rise, a situation that could cause various territories to remain under water in the future.
Most of the cryosphere corresponds to icebergs . Glaciers , sea ice and permafrost provide the rest of the solid water surface. It is estimated that about three quarters of the planet 's fresh water reserves are found in the cryosphere.
The effects of climate change on the cryosphere are multiple, affecting life in general. The cryosphere itself, by melting, contributes to global warming since solid water (ice and snow) reflects solar energy, which returns to space. Instead, as ice and snow melt, the ground is exposed and the Earth's surface absorbs a greater amount of solar energy, which is then radiated into the atmosphere, warming it.
We must highlight the importance of the role that the cryosphere plays in regulating the climate of the entire planet. The reason why certain parts of Antarctica can reflect about 90% of the sun's incident radiation is that ice and snow have a high albedo .
The percentage of radiation that reflects a surface compared to that incident on it is called albedo . By definition, light-colored surfaces have higher albedo values than dark ones, just as glossy surfaces exceed matte ones. The average albedo of our planet is around 38%.
The albedo is dimensionless, that is, it is a magnitude that does not have an associated physical dimension. Its measurement is carried out taking as reference a scale that starts at zero and reaches one as the maximum value. At the first extreme are the bodies that absorb the total of the incident radiation , a theoretical object known as a black body ; The value "one" corresponds to a white body capable of reflecting the total radiation that falls on it.
Precisely, recent snow has an albedo of 86%, the highest value on our planet. If the cryosphere did not exist, therefore, the Earth's albedo would be much lower, its surface would absorb a greater amount of energy and, consequently, the temperature of the atmosphere would also be higher.
Another role of the cryosphere is the disconnection of the oceans and the atmosphere, which reduces the transfer of moisture and momentum (the mass of a body multiplied by its speed at a given point in time); This helps stabilize energy transfers at the atmospheric level.