Going up

How much will sea level rise over this century? “Don’t know” is a good answer. “Not much” is looking like a bad answer that’s getting worse by the month. Last week a group of Northland Conservation Corps workers rode on a hikoi along Ninety Mile Beach to draw attention to the issue:

Tutor Mike Wikitera and his team erected five signs marking predicted sea level rises by 2030. The group, who rode horses to avoid adding to greenhouse gas emissions, erected the first sign at Shipwrecks Bay and placed the last one at Waipapakauri beach on October 30.

But what are the “likely levels” by 2030? The IPCC’s latest report projects between 18cm and 59cm by the end of the century, but only by excluding a very big unknown – how much ice will melt in Greenland and Antarctica. As more evidence of dramatic melt in Greenland arrives, it’s getting increasingly difficult to rule out multi metre rises. The latest number comes from Professor David Vaughan of the British Antarctic Survey, quoted in the Daily Telegraph [UK]:

Prof Vaughan says the main message is not to panic – the effects of melting will be gradual, in the order of three metres per century if the evidence of the past 20,000 years is anything to go by.

Three metres per century? That’s towards the top end of current speculation. 30cm every ten years, ten times the current rate, compares with 17cm over the last century. Prof Vaughan’s right about panic. It’s not a good option, but extreme concern is certainly justified. For some dramatic pictures of what might happen, check out this Greenpeace report on climate change impacts on Spain, timed to coincide with the IPCC meeting in Valencia to ratify the AR4 synthesis report. To see what 3m might mean for NZ, go here and zoom in on your favourite bit of beachfront property. NIWA’s current advice to local government is to allow for 50cm by 2100. That’s in need of considerable upward revision.

Meanwhile, the impact of sea level rise is not just high tides and wet feet. Salt water intrusion into fresh water coastal aquifers can be bad news for agriculture and drinking water – and the problem may be worse than previously thought, according a new study reported by Science Daily. The BBC covers one of the areas at most risk – Bangladesh – in a new series, documenting a boat journey through the country.

9 thoughts on “Going up”

  1. Needless to say, DGV didn’t actually say it, and you really shouldn’t be reporting sensationalist stuff like that.

    He said (pers comm) the usual stuff, which wasn’t exceiting enough for the reporter, who asked, well whats the absolute max SLR; which got the response: the biggest we’ve seen in the past is 3m/century. Somehow, and absolute max has morhped into a prediction. Sigh.

  2. [Note for readers: William (aka Stoat) works for the British Antarctic Survey.]

    Yes, I though the structure of the Telegraph quote didn’t ring true. Any scientist talking about 3m would have made it clear that it was very much towards the top end of the possible. And if he had really said that it should have been headline news. The new earth-friendly Torygraph strikes again.

    In the context of a piece about uncertainty, however, it was fair game – and when it comes to choosing what to cover, I’m the decider… 😉

  3. Unfortunately sensationlism is the name of the game over here at Hot-Topic. Without it you would less likely be able to scare the sheeple into submission.

    Sad considering that this is all just speculation.

  4. Yes very sad how people have become unable to think for themselves. Many peoples lives are already too complicated so these people will just either go along with something or totally ignore it so as not to add more stress to their lives. Phsycologists have given a name to this but I can’t remember what it was.

    Gareth, you yourself used the term speculation in the above article. Admit it, there is no science to predict if where or when sea levels will rise and by what amount. And why, because there are too many uncertanties.

    And you can’t ignore something that doesn’t exist Gareth. :o)

  5. I was dealing with uncertainty. With sea level rise, we don’t know how much there will be, but the danger is that we’ll get more than we thought, not less.

    There’s plenty of information out there, bat. All you have to do is read it. And understand it.

  6. Gareth I read all the time and sorry but I’m not buying into the ‘pre-emptive’ way of thinking. You can’t go through life basing decisions on a ‘what if’ scenario. Where does that stop ? It could be used in so many inappropiate ways.

Leave a Reply