Airports and other critical coastal infrastructure should be subject to risk planning for higher sea level increases than previously expected, researchers at Risk Frontiers and Macquarie University warn.

They say most Australian airports have based risk assessments on Intergovernmental Panel on Climate Change projections for 50-90-centimetre sea level rises around Australia by 2090.

But those projections may be an underestimate, with some emerging studies suggesting a further two meters at least could be added to global sea levels due to West Antarctic Ice Sheet collapses.

“Taking the most low-lying major airports in Australia as an example, our modelling suggests a collapse of the West Antarctic Ice Sheet would see their near-complete inundation – without any adaptation in place,” the researchers say in an article published on The Conversation website.

Cairns Airport is less than three metres above sea level, while those at Sydney and Brisbane are less than four metres above. Townsville and Hobart airports may face issues under a five-metre rise.

Infrastructure at more elevated locations is also at risk and may be inoperable more frequently when the combined effects of storm surges, waves, elevated groundwater and river flooding are considered.

“Given the deep uncertainties associated with the timing of ice-sheet collapse, we suggest airport and other critical coast infrastructure is subjected to risk analysis for a two to three-metre sea level rise,” the researchers say. Read the full article here.