A couple of weeks ago, a Radio New Zealand report caught my attention. The report was on some work being done by GNS Sciences that focused on better understanding ice sheet melt processes.
The boffins at GNS had come to the conclusion that due to these processes, sea-levels may actually be rising faster than previously estimated.
A bit of post radio digging then turned up a recent BBC article that quoted current estimates of global average sea-level rise as being between 0.28 metres and 1.01 metres by the year 2100, according to the Intergovernmental Panel on Climate Change (IPCC).
But, what had really stuck in my mind from all the GNS Science work was that there is apparently a sizeable portion of ice in West Antarctica that has the potential to raise sea-levels by around 5 metres (if this region does melt due to ocean warming).
The reason this had really hit home was because at the time of listening I was busy doing some work on NationalMap’s 3D Road data. This is a data layer we have constructed to enable EV routing calculations in the SwitchMyFleet application and is based on the change in elevation for a route. It had already struck me in the course of this analysis that New Zealand had a significant portion of its road network at low elevation, and that these roads were not just concentrated around Auckland or Wellington (as you’d expect) but were really quite spread across the whole country.
According to the GNS Science team doing the ice sheet research, the best way to mitigate against sea-level rise is for all signatory nations to meet the Paris Agreement targets and limit ocean warming levels. So, without taking the high road here (so to speak) we all have our part to play in this respect…
Mitigation efforts aside though, icesheet and sea-level modelling is a complicated, specialist business, full of uncertainties, so any projections on the likelihood or impact of a 5 metre sea-level rise are categorically not the domain of the team here at NationalMap. However, clearly there is credible modelling that indicates at least the possibility of this outcome, so we thought it might be useful to visualise roads that could be impacted in a 5 metre sea-level rise scenario.
With the following map visualisations, what you want to look out for are the roads (or road sections) that are picked out in red or pink, as they have an elevation of just 5 metres or less.
We’ve selected a few of the more interesting or surprising towns/areas, but the NationalMap Roads dataset is just full of layers of rich data like this that are ready to be visualised – so do get in touch if your business needs something similar.
Blenheim
Christchurch
Dunedin
Gisborne
Napier
Nelson
Wellington
Whangarei
