A groundbreaking simulation conducted by a team of scientists on the United Kingdom’s national supercomputer delves into the worrying trend of ice melt in West Antarctica. The study sought to discern the level of melting that is now inevitable and with which society must adapt, versus the level that can still be controlled by the international community through greenhouse gas emission reductions.
Irreversible Trends Identified
The research team from the British Antarctic Survey found minimal difference between medium-term emission scenarios and the ambitious targets set by the 2015 Paris Agreement. Even under the best-case scenario, where global temperatures rise only by 1.5°C, ice melting rates are projected to triple compared to those of the 20th century, as stated in the press release by the institution.
The Risks of Losing Control
The West Antarctic Ice Sheet collectively contains enough ice to raise global sea levels by up to 5 meters. The alarming fact is that we are losing this ice sheet at an accelerating rate. Earlier models had indicated that this loss could be attributed to rising temperatures in the Southern Ocean, particularly in the Amundsen Sea area.
Considering that millions of people worldwide reside near coastal areas, these communities will be significantly impacted by rising sea levels. Better understanding future changes will thus enable policymakers to plan and adapt more effectively.
What Experts Say
Dr. Caitlin Norton, the lead author of the study published in “Nature Climate Change,” stated, “It appears that we have lost control over the melting of the West Antarctic Ice Sheet. Had we wanted to maintain it in its historical state, action on climate change would have been initiated decades ago.” She added that recognizing the situation now will give the world more time to adapt to impending sea level rises. “If a coastal area needs to be abandoned or drastically redesigned, having 50 years to make those changes will make a difference,” she said.
Projected Scenarios for the 21st Century
The team simulated four future scenarios for the 21st century and one historical scenario for the 20th century. Either the global temperature rise would stabilize at the goals set by the Paris Agreement, between 1.5°C and 2°C, or follow the standard scenarios for medium and high carbon emissions.
In all scenarios, a significant, large-scale warming of the Amundsen Sea and an increase in the melting of its ice shelves were projected. Even under the best conditions, the temperature of the Amundsen Sea accelerated by about threefold, destabilizing the floating ice shelves that help stabilize the interior glaciers, although these began to plateau by century’s end.
A Word of Caution
The worst-case scenario involves only the ice shelf melting but not before 2045. However, the authors noted that this high fossil fuel scenario, where emissions accelerate rapidly, is unlikely to occur. Dr. Norton warns, “We must not cease efforts to reduce our dependency on fossil fuels. What we do now will slow down the long-term rate of sea level rise. The slower the changes in sea level, the easier it is for governments and communities to adapt, even if stopping it altogether is not possible.”
