The Arctic is one of the areas of the planet most sensitive to global warming, and the retreat of its icy mantle has consequences on a planetary level. Now, a study published in the journal Geophysical Research Letters analyzes the results of forty different climate models to try to make predictions about what the situation will be, in the medium term, of the ice that covers the North Pole.
Every summer, the ice sheet that covers much of the Arctic experiences a retreat as a result of rising temperatures, and in winter this icy blanket grows back. As a result of global warming, the Arctic ice sheet has shrunk dramatically in recent decades. In the coming years, the trend of this decline will largely depend on the rate of greenhouse gas emissions.
Low emission scenario
One of the most surprising findings of this study is that, even if greenhouse gas emissions were significantly reduced, the Arctic will likely be ice-free during the summer season.
“If we are able to reduce global emissions quickly and substantially, while keeping global warming below 2 ° C relative to pre-industrial levels, Arctic sea ice will probably also occasionally disappear in summer, ” explains Dirk. Notz, who leads a sea ice research group at the University of Hamburg (Germany). “This will happen even before 2050 arrives, and it is one of the results that has surprised us the most.”
In a more pessimistic scenario, with higher levels of emissions, the Arctic Ocean will be ice-free most of the time, something that would have consequences for the entire planet.
Consequences of ice loss in the Arctic
Last year, the average monthly extent of the ice surface at the North Pole in September , the month in which it normally registers its lowest extent, was the third lowest on record.
One of the most well-known effects of the melting of the poles is the evident rise in sea level, which would bring numerous problems such as floods in some of the most populated cities on the globe and would trigger important migratory flows.
It is known that there is a relationship between the loss of ice at the poles and the atmospheric and oceanic circulation patterns. Its consequences, as well as the feedback mechanisms that are activated cannot be predicted with accuracy, but for example it has been observed that in the years that have been especially hot in the Arctic zone, persistent and anomalous weather patterns have been observed.
In addition, a smaller ice surface implies less reflection or albedo of the solar rays. This in turn causes the earth’s surface to retain more heat and thus a feedback loop is generated that leads to a further rise in global temperatures.
On the other hand, sediments deposited in marine permafrost contain large amounts of methane, a greenhouse gas that will be released in large quantities into the atmosphere as a result of thawing and will continue to contribute to climate change.
Reference: SIMIP Community (2020): Arctic Sea Ice in CMIP6, Geophysical Research Letters https://doi.org/10.1029/2019GL086749
