Climate Outcome NZ
  • Climate Outcome. Home page.
  • Latest posts & news
  • Temperature
  • Precipitation changes in a warming world.
  • Increased flood damage in a warming world.
  • Drought
  • Wind
  • El Nino Southern Ocilation. ENSO.
  • Sea Level
  • Polar melting
  • Arctic sea ice + weather.
  • West Antarctica
  • Ocean Acidity
  • Plant Die Back. Animal Migration.
  • Climate threats
  • Streams a vital resource.
  • Clean energy alternatives.
  • Climate Change in the Bay of Islands
  • The Author. Bob Bingham.
  • Satellite accuracy.
  • Reference sites

Bob Bingham Blog page.

A series of opinion pieces on, mostly climate change and related subjects to do with New Zealand.

Back to home page.

Infrastructure loss in New Zealand due to sea level rise.

25/11/2014

15 Comments

 
Picture
There is a substantial gap in assessment between the latest IPCC report on sea level rise and what scientists, who contributed to the report, believe is going to happen, especially in relation to the ice sheets of Greenland and West Antarctica. The problem is that sea level can change rapidly if there is a sudden collapse of an ice sheet and this is very difficult to forecast accurately. With the absence of reliable forecasting the IPCC opted to predict only what can be proven and this has resulted in a conservative figure of 0.8 metres by the end of the century with middle of the road CO2 level scenario. 
They have also forecast what will happen in a worst case scenario which is where we always are and many scientists working in the field believe that this is a much more realistic forecast. 

The melting of Greenland is accelerating and this alone could add 1.2 metres during this century and Jason Box who studies Greenland has indicated the trend is already evident. Stefan Rahmstorf and other scientists agree.

West Antarctica consists of a string of islands covered in thick ice which is melting from below with warmer sea water, and from above with a warmer atmosphere. The sea ice buttressing the Pine Island and Thwaite’s glaciers has retreated 32 Kilometre’s and is now past the tipping point and will continue to disintegrate. These glaciers and many others in Antarctica are melting at a much faster rate than predicted and can add many metres to sea level.


All this means that we can expect a metre of sea level rise much sooner than the IPCC mid-range report indicates.

With this in mind it would be prudent to start looking at how much infrastructure is going to be flooded with a one metre sea level rise. Our two international airports are both within one metre of sea level and moving them to higher ground is not at all easy, it is exceptionally expensive and needs long term planning, especially with all the related infrastructure.

New Zealand has some of the best climate scientists in the world and has gained valuable knowledge from their research in Antarctica. We should be asking people like Tim Naish of the Victoria University, Wellington and his colleagues for a frank opinion as to when we are likely to have a sea level rise of one metre so that we can make a risk assessment of our infrastructure.

The maps below illustrate some of the threats to four of our major cities.


Picture
Auckland has a low lying section between the airport and Panmure including Sylvia Park which must be borderline to flooding. The runway of the airport is definitely at the one metre level and will be one of the first casualties of the city, should we be building a railway to such a short term resource? Is it wise to build a tunnel to the North Shore or would a bridge have a longer life?

Picture
Wellington airport is also very vulnerable and there is a lot of infrastructure associated with the port which might need to be looked at.

Picture
Tauranga has a lot of port infrastructure and development on the low lying coast which needs to be assessed.

Picture
Christchurch is very low lying and even before the earthquake had many areas which are vulnerable.
Around the country there are many valuable parts of our infrastructure on low lying land, such as the Marsden Point oil terminal and refinery, where we should have a realistic assessment of its future and when we should plan to replace it.

Politicians are notoriously short term planners but climate change is a much bigger event than World War 2 and it is relentless in its advance. The only thing in doubt is the timing.




15 Comments
Baz
27/11/2014 08:47:21 am

Where did you get the figure that the runway at Auckland Airport is on the 1 metre level?

Reply
Bob Bingham
29/11/2014 12:01:10 pm

If you fly over it it is quite obvious but you can also use Floodmaps.
http://flood.firetree.net/
There is a lot of infrastructure going under at one metre.

Reply
Baz
1/12/2014 04:12:49 am

Bob
Thanks, I am very familiar with Auckland Airport, but "Floodmaps" is misleading. The touchdown zone (TDZ) runway 05R is 15ft and runway 23L is 23ft. Play with the programme on downtown Auckland, at 9M lower Queen Street is still above water, even at 20M the Britomat train station is still above. I have also found problems in other locations I am familiar with. I would be very careful using this programme as an authoritive source of information.

Bob Bristow
1/12/2014 03:21:42 pm

If we are looking at Auckland airport specifically - official government documents state (for present risks):

Flooding/Storm surge : At risk from storm surge especially when storm surge coincides with higher than
normal tides. May result in flooding of perimeter of airport

Tsunami: At risk from distantly generated tsunami and locally generated tsunami (impact will be determined by wave
height as anything below 4m is unlikely to impact the airport).

Approach Slopes
-
Existing Runway

Eastern Approach Slope
Starting Level
-
9.66 metres above sea level
---------------------------------------------------------------------------------------

Climate change effects are long term and in the near term the airport will function, there will be increasing inconvenience during storm surges.

We do need a real (scientific) assessment of what sea level rises we are likely to get, it is a long term problem. The IPCC estimates are possibly too conservative.

http://www.aucklandcity.govt.nz/council/documents/districtplanmanukau/maps/2b.pdf

http://www.waitakere.govt.nz/abtcit/whenuapai/pdf/cdemcompartbl.pdf

Bob Bingham
1/12/2014 11:20:12 pm

One metre of sea level rise is critical to much of our infrastructure, Airports do not take kindly to sea water going across the runway. The main road at Takapuna already floods at a good high water and will be permanently flooded at one metre. We need a proper assessment of when this is likely to happen as a lot is at stake.

Reply
Robert Bristow
28/11/2014 03:42:11 am

Thanks Bob for a good article, to remind us of future challenges to increasingly to come in the not so far future.

On the same topic there is an interesting report in today's New Zealand Herald on the Parliamentary Commissioner for the Environment Dr Jan Wright's estimating a 30cm rise by 2050 (based on the conservative IPCC predictions).

http://www.nzherald.co.nz/climate-change/news/article.cfm?c_id=26&objectid=11365463

I understand that sea level rise can cause a negative feedback system on ice sheets which can lift ice and cause Heinrich events (armadas of ice bergs set afloat) - that have caused abrupt sea level rises in previous interglacial periods. Certainly warming subsurface will cause Heinrich events too).

A lot of changes for our grandchildren (and even our children).

http://aos.wisc.edu/~zliu/publications/11_PNAS_Marcott%20et%20al.pdf

Reply
Bob Bingham
29/11/2014 11:48:30 am

The report by Jan Wright was really good and it is to be followed by a survey of the infrastructure at risk. The bit that is still in doubt is the timing on the sea level rise. I am promoting the idea that we should ask the scientists who are researching Antarctica to make an honest assessment of the situation which is different to the IPCC.

Reply
Robert Bristow
4/12/2014 01:47:30 am

Further the very same thread - today's New Zealand Herald has an item from a prominent N.Z climate scientist, concerning Auckland.:-

Auckland must prepare for climate change - scientist
http://www.nzherald.co.nz/climate-change/news/article.cfm?c_id=26&objectid=11368328

and after yesterday's shocking news that the Antarctic melt has tripled over the last 10 years, it begins to suggest the IPCC estimates were very conservative. This increase is likely exponential (not linear).

“The mass loss of these glaciers is increasing at an amazing rate,"
http://climate.nasa.gov/news/2197/


Having worked in local government engineering (admittedly in the early 1970s), I am sure our city engineers are taking note of this and will do their utmost to plan for it, however they do need support from our current and future government leaders.

Stefan Rahmstorf:


The IPCC is conservative
https://www.youtube.com/watch?feature=player_detailpage&v=PJ6HAo_FtD8

Time to blow away the obstinate and muddled denial thinking and take the subject seriously.

Reply
Bob Bingham
4/12/2014 10:07:58 am

Thanks for the contribution Bob. I had the NZ report in the Herald but had missed the NASA report.
The NZ report on infrastructure came out just after my blog on the same subject but what Jan Wright said in a radio interview was that the next report is a more realistic assessment of the timing of sea level rise which is the big area of doubt. Our man Tim Naish has done some good research in Antarctica with the Andril project and their are several bits on Youtube.

Reply
Ian Orchard
3/3/2015 02:14:16 am

"I am sure our city engineers are taking note of this and will do their utmost to plan for it, however they do need support from our current and future government leaders. "
...who are all in deep denial and woefully behind in their homework.

Reply
Bob Bingham
3/3/2015 09:28:34 am

Dr Jan Wright is Parliamentary Commissioner for the Environment and is doing a great job of explaining the dangers but we need a better date for the break up of the ice sheets. Its a lot closer than the official IPCC statement but we have first class Antarctic scientists who can give an informed opinion..

Richard Brent link
10/4/2015 05:08:16 am

Thanks for your great website. I would like to point out a small arithmetic error on the "sea-level" page http://www.climateoutcome.kiwi.nz/sea-level.html

You say "Melting of a gigaton of ice would raise the sea level 0.23 mm. A gigaton of ice is one kilometer high by one kilometer wide and one hundred Kilometers long." However, a cubic metre of water weighs one metric tonne, so a gigaton of ice is approximately 10^9 cubic metres or one cubic kilometer, not one hundred cubic kilometers. On the other hand, the figure 0.23mm is correct for one hundred cubic kilometers, i.e. about 100 gigatons, not one gigaton.

This doesn't change the expected sea-level rises if all the ice in Greenland (or Antartica) were to melt.

Reply
Bob Bingham
10/4/2015 08:18:34 am

Thanks for pointing that out Richard. The figure is actually supposed to be 100 gigatons. Its difficult to read your own stuff and see errors. I had huge difficulty getting that figure but it is fundamental to understanding the melt rates of Greenland and West Antarctica and how it will effect us. That all we are really interested in.

Reply
Michael Gunson
8/4/2016 12:05:22 pm

So what happens with a (conservative) one meter rise in sea level combined with a 12.8 meter swell at the height of a spring tide slamming into the airport extension (9 meters above sea level) breaking out of water of a similar depth that crushed HMNZS F69?

I think $350 million is a very conservative figure for a project that does not take a holistic long term approach to regional air travel, and is obviously susceptible to huge financial blow outs, the bulk of which is rate payer money.

Reply
Bob Bingham
8/4/2016 02:14:33 pm

Good point Michael. New Zealand has loads of infrastructure at only one metre above sea level. I use this web site to check sea level rise and it gives a good indicator. There are spots of water on Auckland airport so that pretty expensive to start with.

Reply



Leave a Reply.

    Bob Bingham 

    Occasional blog posts on topical news items concerning the climate.  Please click the RSS feed to receive updates.

    Picture

    Archives

    January 2023
    November 2022
    June 2022
    May 2022
    May 2021
    May 2020
    April 2020
    March 2020
    September 2019
    December 2018
    April 2018
    March 2018
    January 2018
    December 2017
    September 2017
    June 2017
    April 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    August 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    February 2015
    January 2015
    December 2014
    November 2014
    October 2014
    September 2014
    August 2014
    July 2014
    June 2014
    May 2014
    April 2014
    March 2014
    February 2014
    September 2013
    May 2013
    April 2013
    March 2013

    RSS Feed

    Categories

    All
    Clean Water
    Climate Change.
    CO2 Levels
    El Nino
    Floods
    Methane
    Ocean Acidity
    Pine Island Galacier
    Sea Level Rise
    Soil Loss
    Storms

    RSS Feed

Proudly powered by Weebly