Friday, August 09, 2019

Climate Change: The cost of sea-level rise

We've had some grim projections about sea-level rise in the last week, with Wellington Regional Council notifying storm surge risks for a 1m sea-level rise, and Wellington City Council expecting 1.5m by the end of the century. How much is all this going to cost us? A shit-ton:

Every 10cm of sea level rise puts several thousand more New Zealanders in a position they might rather avoid: living in an area that could be flooded by an extreme storm.

Modelling has found that each added 10cm puts at risk another 7,000 New Zealand buildings, worth an estimated $2.48b to replace, 133km of roads and 10km of railway line.

To put this in context, seas have already risen almost 20cm globally since pre-industrial times and 1m of sea level rise is considered a middling projection for 2100.

A metre means $25 billion. Wellington's expected 1.5m means ~$38 billion. The latter is roughly the cost of the Christchurch rebuild, or about 40% of a years government spending, which is a staggering amount. And the way things are going, we'll probably find out that these were conservative estimates.

The even scarier thing is that the amount of carbon we have put into the atmosphere means we are already committed to at least a half-metre by 2100, and more after that (because warming and sea-level rise doesn't just stop after then). So we're going to be paying at least half a shit-ton. The challenge is to ensure we don't have to pay the rest of it.