It is a real ecological drama that is playing out in the Arctic, where the sea ice and its inhabitants are slowly dying.
In the most remote regions of the Far North, in the depths of Greenland, hides a real ecological treasure: the “Last Ice Zone”(LIA). This is a permanently frozen area, which researchers have long thought would remain trapped in the ice forever. We now know that it is on borrowed time, and a new study has recently come to highlight the impact of this situation on local biodiversity.
American and Canadian researchers have thus attempted to anticipate the evolution of this LIA by 2050, in a large, well-documented study. They simulated two distinct scenarios. The first, enough optimistic, corresponds to a situation where “measures ambitious ”and“ways considerable”Are implemented to fight against global warming. The second, more pessimistic, imagine that the climate will continue to change at the current speed.
The first worrying observation is that the optimistic and pessimistic simulations presented more or less the same conclusions; within 30 years, the LIA will undergo a “thinning dramatic”, Almost independent of our efforts to preserve it. This suggests that it could be already too late to save this important structure.
A disaster for biodiversity
In the most optimistic scenario, a little bit of ice could still persist during the summer period. But that would require that we succeed in drastically reducing greenhouse gas (GHG) emissions. Otherwise, it is the pessimistic scenario who will take precedence. And in this case, by 2100, the ice in the area could be completely melted during the summer period.
An obviously catastrophic situation for local biodiversity. This particularly concerns seals and famous polar bear, oh so photogenic ambassador of the climate crisis. “If annual ice disappears, all ecosystems that depend on it will collapse”, Explains Robert Newton, lead author of the study.
Indeed, this pack ice is a precious element, which provides an essential contribution to the richness of the marine ecosystem. First, it provides a Safe Haven to a whole bunch of species by isolating them from humans. It also has many caves, crevices and cavities. These serve as refuge local species, especially bears that hibernate there and raise their young.
In the hollows of these multi-year ices, we find small unicellular microalgae, the diatoms ; they are indispensable in many ways, including being one of the main sources of food for heaps of small organisms. These are the basis of the diet of fish in these areas. The latter then end up on the plate of the seals, which are themselves the favorite feast of the polar bears.
Dollars against diversity, a duel lost in advance?
If all the ice melts during the summer, then these species are deprived of their habitat. But above all, we cut the food chain directly at the base. Without ice, no diatoms; there is therefore no food for the fish. This shortage in turn impacts the seal population, and ultimately affects bears. As it stands, we are heading towards the end of the Last Ice Zone as we know it.
The researchers however refuse to fatalism, and prefer to conclude their paper on an optimistic note. They explain that if we manage to make enough progress in the short term, the sea ice could just survive long enough so that the temperatures start to drop again. The Last Ice Zone could then begin to develop again.
For researchers, this will require the establishment of numerous protection zones all over the arctic, as in Tuvaijuittuq . But this implies that political decision-makers and large industrial groups resist the temptation to go and exploit the huge deposits of oil and precious metals areas that provide ice for the LIA. And if we would sincerely like to share the optimism of the researchers, there is a real chance that the survival of this ecosystem does not weigh very heavily in the face of potential billions of dollars …