Not too long ago the Arctic Ocean was covered in its entirety by ice throughout the year, including in summer. In winter, the ice sheets were much larger and spread over the lower latitudes, eventually covering the Greenland Sea and the Bering Sea. In summer, due to temperature increases, the ice sheets retreated, however, the frozen edge reached very close to the coast.
This situation is changing over the years. Each time the ice caps are smaller and there is less frozen area. What would happen if the Arctic were completely ice-free?
Receding ice sheets
The situation in which we saw ourselves before and the one we have now is totally different. A surface that back then it had about 8 million square kilometers in the month of September, today only has during that month about 3-4 million square kilometers. September is the month when the ice sheets retreat the most. This indicates that the thickness of the ice sheets has been reduced by half. Summer ice is only a quarter of the volume it was in the 1970s. Analyzing these figures is crucial to understanding the consequences of the total melting of the Arctic ice.
Due to global warming, the Arctic is advancing its thaw twice or triple the speed of the rest of the world. This is due to the transport chain of heat coming from the equator. This acceleration of Arctic warming will lead to an ice-free summer in the short term.
Each year that annual temperatures are recorded, we realize that it is hotter than the previous one, with 2016 being the hottest since temperatures began to be measured there in the 1880s. Formerly, when the Arctic ice was observed, there was talk of multi-year ice. This meant that the ice that was observed had formed several years before and that it lasted after the passage of the seasons. Due to the years in which it had been formed, they could reach great heights, rugged topography and large ridges that prevented the passage of explorers and ships.
Today almost all the ice that is observed is of the first year. That is, it has been formed during the current season. They usually only reach it is 1,5 meters thick and has no more than a few ridges. The ice that forms in a single winter (and taking into account that the temperatures are increasingly higher) can melt during a single summer. This causes a summer ice death.
Consequences of the disappearance of the ice
Decreased albedo
Since we started talking about global warming and climate change, we have been talking about the melting of the Arctic and Antarctic ice. Well, the consequences of the disappearance of these great ice sheets they are very dramatic for the planet. Albedo is the percentage of solar radiation that the earth's surface reflects or returns to the atmosphere. Well, one of the consequences of the disappearance of the ice sheets would be the reduction of the albedo from 0,6% to 0,1%. This leads to greater heat retention on the Earth's surface and, therefore, an increase in global temperatures. You can learn more about this phenomenon in the melting of the oceans.
The problem with albedo is that the summer ice is retreating at a time when a lot of solar radiation is being received. The continued disappearance of ice is reducing albedo around the world. This contributes 25% to the direct effects of global warming caused by humans. It is also being observed that, as the sea ice disappears, coastal snow melts much faster in spring, due to the warmer air masses that arrive from the clear sea.
Rising sea levels
A second consequence of the retreat of the ice sheets is better known. It is about of rising sea levels. Summer ice is now only a quarter of what it was in the 1970s. This causes meltwater to circulate through the ice caps and end up in the sea, raising sea levels. IPCC experts have estimated a sea level rise of more than one meter. This irreversible change will have disastrous effects on coastal cities like Miami, New York, Shanghai, and Venice, as well as increasing the frequency of flooding on flat, crowded coasts like Bangladesh. You can find more information on the related impacts at the diet of polar bears.
To better understand these implications, it is relevant to study how the The melting of Antarctica poses a danger to humanity.
Methane emissions
A third consequence is the most imminent threat to humanity. Is about methane emissions from the seabed. The Arctic has its own air conditioning system that works as long as ice sheets exist on the surface of the water. In summer, even if there is little ice, the water temperatures cannot rise above 0 degrees. That is why the air conditioning system is maintained. However, when the ice melts completely in summer, the water masses can heat up to about 7 degrees, absorbing solar radiation (since there is no ice to reflect it). In the Arctic, the continental shelves are very shallow, so that the solar radiation that absorbs the water reaches the sea floor, melting the permafrost that has been there since the last Ice Age.
The sediments that we find in the marine permafrost have large amounts of methane retained, so its thawing would generate the release of large columns of methane. Methane has a greenhouse effect 23 times greater than carbon dioxide, so their release into the atmosphere would further increase global warming. If these methane plumes are released into the atmosphere, it could contribute to an increase in global temperature of 0,6 degrees by 2040. You can also read about the permafrost and methane.
Another great danger to the well-being of our world is the probability that the warming Arctic and the disappearance of sea ice are the cause the extreme weather we have experienced in the last six years, with very cold or stormy winters in certain parts of Europe and North America and very warm weather in other areas.
Jet stream
There is the call jet stream which is the one that separates the Arctic from the lower latitude air masses. Well, this jet stream is slower than before, because the difference in temperatures between the waters of lower latitudes and the waters of the Arctic has been reduced. The fact that the jet stream is slower allows the local meteorological systems of a single phenomenon to be prolonged such as droughts, floods, heat waves, etc.. The greatest repercussions of the slowness of this current are occurring in countries in the intermediate latitudes of the northern hemisphere where the most productive farmland on the planet is found. If this effect persists, global food production could be in serious jeopardy, leading to famine, rising food prices and wars.
Ocean conveyor belt
The last consequence of the disappearance of the ice may have some advantage. exist a very slow thermohaline circulation that is not propelled by the winds, but rather the distribution of heat and rainfall over the seas. This circulation is known as the conveyor belt. Basically, it is a current in which the masses of hot water circulate in the direction of the Arctic and as they cool down they become more salty and dense. This increase in density causes the water masses to sink and circulate again towards lower latitudes. When they reach the Pacific, they warm up again and being less dense, they return to the surface. Well, in the area where the bodies of water sink due to becoming cold and dense, no ice has been seen since 1998. This causes the conveyor belt to stop working, causing the water to cool less. The advantage that this can provide is that, by the end of the century, the United Kingdom, Ireland, Iceland and the coasts of France and Norway (in addition to north-west Spain) They will only rise 2 ° C, compared to a terrible 4 ° C for most of continental Europe. This is good news for northwestern Europe, but not for tropical America, because the loss of the current will increase the temperature of the Atlantic waters in that area and, as a consequence, the intensity of the hurricanes.
A future without ice
These data on the effects and consequences of the disappearance of the ice are very important for several reasons. The first is that it shows the nullity of the arguments about the economic benefits that thaw would have to facilitate maritime transport and offshore oil exploration. This situation can bring governments billions of dollars in profits. However, the cost of the warming that makes this possible is estimated in trillions of dollars.
The second shows that the future of global warming cannot be done in a linear way, considering only CO2 emissions, but also considering that there are numerous factors that intervene in the acceleration of warming and may end up dominating the pattern. I have pointed out the effect of the reduction of albedo and the release of methane from marine sediments. This is why it is possible that, even if we reduce CO2 emissions globally, the system will not react in the same way because greenhouse gases are increasing in the atmosphere and the amount of heat absorbed by the Earth is increasing. To better understand this phenomenon, see the article on the Totten Glacier and its melting.
As you can see, there are serious consequences to the disappearance of ice on the planet. One of the possible solutions is not to reduce the amount of CO2 that is discharged into the atmosphere, but rather to a CO2 absorption technique to remove it from the cycle. However, human beings are losing one of the ecosystems that the planet needs most and that we use to have the life that we can have today.
