Scientists say parts of Antarctica face “catastrophic” and “irreversible” impacts from climate change unless urgent steps are taken to limit greenhouse gas emissions.
International researchers are sounding the alarm after modeling best- and worst-case scenarios for the Antarctic Peninsula under different global warming impacts.
Rich in wildlife, the peninsula is already one of the warmest regions on earth and is a major hub for scientific research, tourism and fishing on the icy continent.
The Adélie penguin population in Antarctica is particularly at risk. (By: Bethan Davis)
“That future depends on the choices we make today,” said lead author Professor Bethan Davies from Newcastle University, UK.
“In a future with low emissions, the most important and harmful effects can be avoided.
”However, scenarios of increased emissions risk the loss of sea ice, ice shelves, glaciers, and iconic species such as penguins.”
The decline in krill could have implications for penguins and other species, the study found. (ABC News: Jano Gibson)
The report is Published in Frontiers of Environmental Sciencemodeled the impact of three different scenarios expected by 2100 and beyond.
- In regions with low emissions, global temperatures are already 1.8 degrees warmer than pre-industrial levels, meaning we have already warmed by about 1.5 degrees.
- Moderate to high emissions (3.6 degrees above pre-industrial levels)
- Very high emissions (4.4 degrees above pre-industrial levels)
Eight different aspects of the Antarctic Peninsula’s environment were investigated for potential future impacts.
These include ice shelves, sea ice, land ice, marine ecosystems, terrestrial ecosystems, the Southern Ocean, the atmosphere, extreme events, and operational impacts.
Under higher emissions scenarios, modeling showed changes that were “irreversible on human timescales.” (Provided by: Peter Convey)
The study found that lower emissions lead to “gradual changes” in sea ice, ice shelves, and land ice.
Under the moderate scenario, modeling showed further changes, including an increase in the severity and frequency of extreme events and “local extinction events.”
“This scenario, which is closest to the current trajectory, would result in ice loss at a faster rate than today, significant and virtually irreversible changes in habitat, damage to infrastructure, and a difficult operational environment,” the report said.
Modeling under higher emissions scenarios showed “long-term and interrelated changes that are irreversible on human time scales” including:
- Number of days above 0 degrees Celsius increases from 19 to 48 days per year
- Sea ice area decreases by 20% during winter
- Ranges of key species such as krill shrink southward, impacting predators such as penguins and whales
- Significant increases in the frequency and intensity of extreme events, including atmospheric and oceanic heatwaves
- Ice shelves will become significantly thinner and ice will be lost in the southern part of the peninsula.
- Accelerating ocean warming, rising temperatures and increasing likelihood of liquid precipitation
- Glacier retreat and ice shelf collapse
The report acknowledges the “uncertainties” in predicting future changes with confidence, but concludes that a low-emissions pathway offers the best chance of protecting the region.
“Increasing emissions pathways…will result in dramatic and irreversible changes to the peninsula, damaging its charismatic wildlife and unique ecosystems, contributing to sea level rise, and creating significant operational challenges in a region of increasing global geopolitical interest and competition,” the report said.
“Averting such catastrophic changes in these fragile polar regions requires urgent action to keep global temperatures below 2 degrees Celsius and warming as close to 1.5 degrees Celsius as possible.”
Modeling of the high-emissions scenario showed “glacial retreat and ice shelf collapse.” (Provided by: Professor Peter Convey)
Professor Davis said future changes in Antarctica would have significant impacts elsewhere.
“Although Antarctica is far away, changes here will affect other parts of the world through changes in sea levels, ocean-atmosphere connections, and changes in circulation,” he said.
”Changes in Antarctica are not limited to Antarctica.”