The most important Arctic oasis is susceptible to climate change: Researchers say global warming is threatening the region’s ecosystem and predict that the oasis will cease to exist.
The Environmental Change Research Unit (ECRU) of the University of Helsinki participated in an international study investigating the millennial history of the most important oasis in the Arctic and the possible effects of climate change on its future.
North Water Polynya is a year-round open water area located between northwestern Greenland and Ellesmere Island, Canada, in northern Baffin Bay, which is otherwise covered by sea ice approximately eight months of the year. .
The area is known as an Arctic oasis, and one of the main migration routes for the original Greenlandic population lies just north of the area.
In the study, microfossils and chemical biomarkers conserved in marine and lake sediments were analyzed as keys to the past, exposing the historical variation in North Water Polynya over the past 6,000 years.
The high rate of primary production of the polynya, for which, in marine environments, diatoms and other microalgae are responsible, maintains a diverse and unique ecosystem that serves as a safe haven for a variety of species in Arctic conditions, which of otherwise they would be harsh.
Arctic keystone species, such as the polar bear, walrus, and narwhal, also thrive there. For indigenous populations who depend on hunting and fishing, this area, the largest polynya in the Northern Hemisphere, has been a lifesaver.
According to the study, the polynya was stable and its primary production was high about 4,400-4,200 years ago, at the time when people arrived in Greenland from Canada via the frozen Nares Strait.
However, the stability of the polynya has varied over the past millennia: during the warmer climatic periods of 2,200-1,200 years ago, the area was unstable and its productivity was drastically reduced. When primary production rates are low, there are significant reductions in populations of organisms at the upper levels of the food web, such as zooplankton, fish, and marine mammals.
“According to archaeological finds, there were no inhabitants in the area during this period. It is a mystery that can potentially be explained, in light of the research findings, by conditions that were unfavorable for people who depended on hunting and fishing, ”researcher Kaarina Weckström from the Research Unit of the United States said in a statement. Environmental Change from the University of Helsinki.
The researchers noted that air temperature has never reached the current level in northwestern Greenland in the 6,000-year history of the studied polynya. Global warming and shrinking sea ice caused by human activity have caused the polynya to become unstable.
The area is maintained by favorable ocean currents and winds, and in particular by an ice bridge located to the north of the polynya, which prevents drift ice in the Arctic Ocean from moving further south. It is the annual formation of this natural block that now threatens the warming of the climate.
“This area, the most important oasis in the Arctic, is likely to disappear if temperatures continue to rise as expected. It would be important at least to curb climate change, so that the indigenous peoples of the Arctic have some kind of opportunity to adapt. On the other hand, as the history of the polynya suggests, if we can reduce greenhouse gas emissions and mitigate rising air temperatures, both the Arctic sea ice and the polynya can be restored, ”Weckström summarized. (Europa Press)
Basic data from the IPCC report
– The global average temperature was 1.09 ° C higher between 2011-2020 than between 1850-1900.
– The last five years were the hottest on record since 1850.
– The recent rate of sea level rise has almost tripled compared to 1901-1971.
– Human influence is “most likely” (90%) the main driver of the global retreat of glaciers since the 1990s and the decline in Arctic sea ice.
– It is “practically certain” that extreme temperatures, including heat waves, have become more frequent and intense since the 1950s, while cold events have become less frequent and less severe.
The new report also makes clear that the warming we have experienced to date has led to changes in many of our planetary support systems that are irreversible on time scales of centuries to millennia.
The oceans will continue to warm and become more acidic. Mountain and polar glaciers will continue to melt for decades to centuries.
“The consequences will continue to get worse with each warming,” Professor Ed Hawkins, from the University of Reading, UK, told BBC Mundo. “And for many of these consequences, there is no going back,” he added. (BBC World)
A key aspect of the report is the expected rate of increase in temperatures and what it means for humanity.
Almost every nation on Earth adhered to the goals of the Paris climate agreement in 2015.
That pact aims to keep the rise in global temperatures well below 2 ° C this century and to continue efforts to keep it below 1.5 ° C. (BBC World)
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Global warming threatens arctic oasis | The newspaper