CLIMATE CHALLENESCatastrophic Sea Level Rise Possible within Our Lifetime? Yes, Here’s How
This prospect of near-term runaway sea level rise is considerably more serious than sea level projections issued by the Intergovernmental Panel on Climate Change (IPCC). There is thus an urgent need for climate experts to advise the government on strategic planning and risk management. This is especially true for our intelligence and national security communities.
‘Runaway ice loss causing rapid and catastrophic sea level rise is possible within our lifetime,’ according to a joint emergency statement released by more than 300 scientists at the inaugural Australian Antarctic Research Conference in Hobart last month.
‘The East Antarctic ice sheet alone,’ the scientists stated, ‘holds enough water to raise global sea levels by approximately 50 meters.’
This prospect of near-term runaway sea level rise is considerably more serious than sea level projections issued by the Intergovernmental Panel on Climate Change (IPCC), which forecast an average 40 centimeter rise under the best-case emissions scenario by the end of the century and 70 centimeters under the worst-case scenario—the trajectory on which we are currently tracking.
The explanation for this discrepancy is acknowledged, though often overlooked, within the depths of IPCC reports: positive feedback loops. These processes are too complex to be fully integrated into current global climate models, which means they aren’t accounted for in sea level rise projections.
The resulting blind spots could be pivotal.
As such, the need for climate experts to advise the government on strategic planning and risk management is becoming urgent. This is especially true for our intelligence and national security communities. We cannot make and follow plans that rely solely on model projections. Rather, models must be contextualized by climate experts to ensure that critical feedback loops such as marine ice sheet and ice cliff instability are properly accounted for—and hence that resulting threats are managed.
Given that about half of all Australians live within seven kilometers of the coast, the impacts of runaway ice loss on Australia’s domestic security would be immense. For context, greater Sydney’s average elevation is 53 meters above sea level; Melbourne’s is 49 meters; Brisbane’s is 45 meters; and Perth’s is 26 meters.
These cities would become uninhabitable, mostly because of direct inundation, but also due to coastline retreat from storm surges and erosion. The latter cannot be overstated. As one centimetre of sea level rise results in an average coastline retreat of one metre, a 50 meter sea level rise would cause coastlines to retreat by several kilometers. Hence, even the areas of higher elevation within Australia’s most populous cities would be in a serious predicament.
Without planning and preparation, the security and strategic ramifications of this would be catastrophic. This is even before we account for regional implications, considering that Asia has the largest near-coastal population in the world.
