Turning on coastal living
about with rising seas is storms.
The sea-level is the base from which major events like storm surges spring. When the base is higher, so too is the surge.
The January storm was particularly bad due to an unfortunate combination of events. A low pressure system had moved from the sub-tropics, and have manoeuvred their communities to live as near to it as possible.
Perhaps the best evidence of this is found in the country’s most common street name: Beach Rd.
The consequence is that billions of dollars of infrastructure, much of it publicly owned, is in areas most immediately threatened by rising seas. They include airports, roads, underground pipes, parks and reserves, community facilities and social housing. The replacement cost of these assets is many billions of dollars, and does not include the insured private property.
The speed at which the sea rises is vitally important, because it dictates how much time is available to move these assets.
Based on the amount of greenhouse gases already in the atmosphere, scientists project with high confidence 20cm to 30cm of sea-level rise by 2065, regardless of how emissions are reduced.
The uncertainty is in what happens next. In a best-case scenario, where emissions are quickly reduced, sea-level rise could be slowed to half a metre by 2100. In a worst-case scenario, where business as usual continues, the rise could reach between 1m and 2m, or possibly even higher, by 2100.
Public planning documents typically end at this point, about a century from now. That becomes a problem for future generations.
‘‘The critical thing around sea-level rise is that it’s not going to stop,’’ says Dr Judy Lawrence, a climate change researcher at Victoria University of Wellington. ‘‘It’s going to keep going for centuries, and we don’t know exactly when the reduction in emissions will start to kick in and slow that down.’’
It has prompted a flurry of questions among scientists and researchers: How do you fairly plan for a future no-one alive today will experience? And who will bear the cost of a slowly unfolding disaster that, unlike the disasters we’re familiar with, is entirely predictable?