Met Office Report Says Sea Levels Likely to Rise 11-16 cm by 2030?

Update 11 Feb 2014: Met Office says Oh, you thought we meant from now? No, from 1990! See comment from Richard Betts, below and the updated Met Office report.

13 Feb: A further comment from Richard confirms that the Met Office projections for UK sea level rise are 5 to 7 cm between now and 2030.

This is an edited version of a comment I made on Bishop Hill on 9 Feb:

In February 2014 the Met Office and Centre for Ecology and Hydrology (CEH) published a report called “The Recent Storms and Floods in the UK”. (pdf of original version here). The report makes an interesting prediction about sea level rise by 2030 on p.21 (the same figures are also given on p.2):

Sea level along the English Channel has already risen by about 12cm in the last 100 years. With the warming we are already committed to over the next few decades, a further 11-16cm of sea level rise is likely by 2030. This equates to 23-27cm of total sea level rise since 1900. We are very confident that sea level will continue to rise over coming decades as the planet continues to warm. These numbers represent our current best estimate for the UK.

That implies that the rate of sea level rise (SLR) in the English Channel will more than double in the next 16 years to 7 to 10 mm per year (on average) from the current 3 mm per year. And assuming that the rate of SLR does not leap to the new level in the first year, a linear increase from the current rate implies a rate of about 15 mm per year by 2030.

Is there something special about the English Channel? It’s hard to reconcile this with the IPCC projections in AR5 Chapter 13.

No citations are given for this statement in an otherwise well-referenced document. I’ll update this post if I find out more.

Update: Tim Channon has plotted a graph of how this prediction compares to past SLR at Newlyn, Cornwall (the national sea level monitoring station) http://tallbloke.wordpress.com/2014/02/10/met-office-forecasting-skill-on-show

Update 2: Richard Betts is on the case…


Update 3: I think Tim Channon may have nailed the problem (2030 should be 2100?). Although, this would mean that the Met Office is expecting no acceleration of SLR over a century, while the IPCC expects it to at least double by 2080-2100. We’ll see what the Met Office comes up with.

This doesn’t turn out to be the Met Office’s error, but you can see his original graph at http://tallbloke.files.wordpress.com/2014/02/mo-newlyn-2.png

Update 4: The Met Office have ‘clarified’ their statement, which apparently relates to a 1990 baseline. See Richard Betts’ comment below. See also Tim Channon’s new post and graph: tchannon-image-356

Update 5: A few final thoughts from me in a comment below.

Update 6: Nic Lewis tackles the UKCP09 projections on Bishop Hill and Euan Mearns looks at the Met Office report as a whole on his blog.

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48 thoughts on “Met Office Report Says Sea Levels Likely to Rise 11-16 cm by 2030?

  1. Sea-level is rising a] because of sediments washed from land into the sea every year b] because Aral sea, lake Chad are almost dry – that water ends up into the oceans PLUS deserts are expanding; simple logic -> less water on the land = more water in the sea

    sediments wash is almost always the same, BUT, for the last 100y lots of dams have being built. Only 10m3 of water in a dam = on 10km2 less water in the sea by 1mm: http://globalwarmingdenier.wordpress.com/sea-rising-or-not/

  2. I’m still trying to parse this phrase ‘a further 11-16cm of sea level rise is likely by 2030‘.

    Is the Met Office using IPCC-style ‘calibrated’ uncertainty, so likely means 66 – 100% certain? And is the 11-16 cm range a 95% confidence interval, or something else? Are they 2/3 certain that they are 95% certain of this range? We just need a ‘medium confidence‘ in there to make our joy complete.

  3. Based on expert judgement it is likely that the Met Office has made an error of some kind in assembling this document, but I have low confidence in any of my guesses as to precisely what the error might be.

  4. Hi Ruth

    The projected SLR of 11-16cm by 2030 for the English Channel comes from the UKCP09 projections, see this report, Table 2, columns for “High” (16.0) and “Low” (11.4) for London.

    But crucially, these numbers are relative to 1990 (the UKCP09 baseline), not 2014. This was not stated. Clearly there’s been some sea level rise since 1990, so the numbers between 2014 and 2030 would be smaller.

    Also, these numbers are for relative sea level rise, including both climate change and vertical land movement.

    So, Athelstan on Bishop Hill was right that this was part of the reason for the numbers seeming large compared to the AR5 global projections, and you were also right that there was more to it than that.

    The report has been updated, and page 2 now says:

    Sea level along the English Channel has already risen during the 20th century due to ocean warming and melting of glaciers. With the warming we are already committed to over the next few decades, a further overall 11-16cm of sea level rise is likely by 2030, relative to 1990, of which at least two-thirds will be due to the effects of climate change.

    and page 21 now says:

    Sea level along the English Channel has already risen by about 12cm during the 20th century; this is over and above the increases associated with sinking of the southern part of the UK due to isostatic adjustment from the last Ice Age. With the warming we are already committed to over the next few decades, a further overall 11-16cm of sea level rise is likely by 2030, relative to 1990, of which at least two-thirds will be due to the effects of climate change. We are very confident that sea level will continue to rise over coming decades as the planet continues to warm, and these numbers represent our current best estimate for the UK. Clearly sea level rise from whatever source has to be factored into discussions about resilience to coastal and river inundations.

    References are now included in that paragraph.

    Thanks very much for spotting this!

    Cheers

    Richard

    [Ruth: Many thanks, Richard, for your efforts on this. There are aspects of all this that I find deeply disturbing but which I'll write about when I've thought about it further. In the meantime, thanks for your good-natured and rapid response. (15.02.2014: My final thoughts in comment below).]

    • Richard, those figures don’t jibe with other sources. For example, Table 2 shows the rise at London from 1990-2010 as 6.2 mm (medium), or 3.1 mm/yr. According to NOAA, the long-term rate of sea level rise at Sheerness is 1.66 mm/yr. It doesn’t seem to be following a straight line of late, so it’s a bit hard to guess the recent trend, but visually it doesn’t seem far off the long-term rate. Presumably the land is rising around there, as that’s less than the global average.
      On the other side of the Channel, Dunkirk shows a rate of 1.71 mm/yr.

  5. The 2011 update of Church & White finally included a simple average of world tide gauges, alas plotted in yellow atop darker traces, obscuring its pencil straight linearity over the last 150 years, extracted in black with an added trend line, here:
    http://i51.tinypic.com/28tkoix.jpg

    This should be the end of the whole Global Warming debate.

    Instead, NASA simply cuts this data off in its official public tutorial, plotting systematically mismatched satellite data next to it, hiding the fact that tide gauge data falsifies claims of a rate increase:
    http://s6.postimg.org/cdfc600dt/image.jpg

  6. Okay, I’ve reworked the plot, still pleased to see me.
    If there is a blank here, a plot didn’t take.

    I was going to do a post on my own blog on things to do with the Newlyn data, of low interest to most readers. Might put up a new post at the Talkshop.

    [Ruth: No, I can't see a plot or URL in your comment. Look forward to your post on the Newlyn data.]

  7. Pingback: Met Office sea level forecast, update | Tallbloke's Talkshop

  8. Pingback: There is nothing like a(n extreme) Dame | The View From Here

  9. Richard Betts,

    It is good of you to comment here and to bring news of this update, but are you really happy with this mealy mouthed and misleading change?

    There are several things badly wrong with this response. The first thing is the complete failure to acknowledge the original error or the fact that it has been corrected. I see that the pdf has been changed, but there is no note in the pdf to this effect, and there is no note on the html page. Similarly the choice of words in the revised text is deeply obfuscatory, and seems almost designed to confuse: “a further overall 11-16cm of sea level rise is likely by 2030, relative to 1990″ is self contradictory drivel.

    I know that you recently stated on twitter that “[the] Met Office doesn’t take part in the REF, as it’s not academia”, but I was under the impression that many staff considered themselves to act as academics, with visiting professorships at universities, and/or quasi-academic titles. There are certain basics standards in academia relating to the accuracy of the formal record, and this “update” drives a coach and horse through them. If you want to do this properly, then (1) the revised report should have “Revised on 10/02/2014″ on the front cover; (2) the appropriate paragraphs should be rewritten from scratch to describe the real situation clearly, rather than pretending that the original text was “almost OK”; (3) a footnote should be added stating “An earlier version of this report incorrectly stated that …. which has now been corrected. We thank Dr Ruth Dixon (University of Oxford) for bringing this to our attention.”

    Overall this sorry affair simply acts to feed the impression that the Met Office is a bunch of amateurs who are more concerned about the political impact of their reports than their actual content. This impression may, perhaps, be unfair, but it is hardly irrational, and choosing to feed it is extraordinarily unwise.

    • Even BBC gave a reason why their article had been changed. Ref decade forecast reporting being misleading last year. Albeit only after I reminded David Shipman out their editorial standards demanded it

      if the Met office were being informative to the public. They would say. How much from now (including saying from 1990)

  10. As Jonathan says, the revised statement “a further … relative to 1990″ is complete nonsense, and makes the Met Office look even more foolish.

    Over the next 16 years, I expect to age a further 40 years, relative to 1990 levels.

  11. Pingback: Met Office Sea Level Forecast – No Resemblance To Reality | NOT A LOT OF PEOPLE KNOW THAT

  12. Pingback: Met Office Sea Level Forecast: No Resemblance To Reality | The Global Warming Policy Foundation (GWPF)

  13. The misleading Met Office error has now propagated to the Guardian

    “The joint report, from the Met Office and the Centre for Ecology and Hydrology, entitled The Recent Storms and Floods in the UK, points out that the 12cm (4.7in)rise in sea level over the 20th century has exacerbated coastal flooding. It says a further rise of between 11cm and 16cm is expected by 2030, two-thirds of which is attributable to the effects of climate change.”

    • And here in the Guardian as well:

      Flooding will become worse due to the rise in sea level, which has already risen by about 12cm in the past 100 years, with a further 11-16cm rise projected by 2030.

      Fortunately @flimsin is working on this one so we may see some action

      • apparently Lord Krebs (climate change committee) has written to The Times today, mentioning 12 cm by 2030

        Ruth: Wow! I’ve not see the Times, but it seems to be this Open Letter from the CCC which doesn’t actually specify the start date but allows that interpretation.

    • Some interesting claims apparently from the Director of the Cabot Institute below the Paul Bates article in the Guardian:

      Many very insightful comments here – we could not make all the points we wanted to in this article but there is some excellent elaboration on many issues here (for example, the isssue of oversteepening banks). I also have to highlight the contributions of our colleague Hannah Cloke at Reading who has been engaged with this debate from the outset. And Simon Jenkins comment this morning was also excellent – gu.com/p/3mk7m

      As someone who contributed to the article, I did want to make one clarification. Our original text on sea level stated: “And finally, if we are going to consider long-term planning, we must consider climate change impacts. Flooding will become worse due to sea level rise, which has already risen in the English channel by about 12cm in the last 100 years, with 11-16cm of sea level rise projected for the period between 1990 and 2030 (although not all of this is due to climate change).”

      When editing it down, some of the key nuance was lost, implying that climate change will have caused 23-28 cm of sea level rise from about 1910 to 2030. That is an overstatement. While there is no doubt that sea level rise is not helping and will cause this challenge to become worse, it is important to get the details right! You can read more about this in detail at the Met Office’s report: http://www.metoffice.gov.uk/media/pdf/n/i/Recent_Storms_Briefing_Final_07023.pdf

      Note that the link in this comment is to the original error strewn Met Office report and not to the new shiny incomprehensible one. This then gets corrected below:

      Final version of Met Office report. Thanks @richardabetts http://www.metoffice.gov.uk/media/pdf/1/2/Recent_Storms_Briefing_Final_SLR_20140211.pdf

      Make of this what you will.

      • As I had noted on my own blog about the evolution of this shoddy – and at least twice “updated” – unprofessional so-called “briefing” from this “jewel in the crown, of British science and global science” (after a few runs through the Gunning Fog Index) even the Summary:

        [...] was not intended for a “wide audience” – and it’s way out of the communication ballpark if Dame Julia and her ten co-authors were aiming for “near-universal understanding”.

        In light of the word counts and fog index, some might conclude that the main purpose of this “briefing” was simply to have something in the way of pseudo evidence to which Dame Julia – and others of the advocacy persuasion – might point if, Gaia forbid, push came to shove and they were actually challenged while flogging the unscientific extreme meme. But I couldn’t possibly comment ;-)

        I wanted to see if any of these “updaters” – whose ideas of clarity, provenance, traceability and accountability seem to parallel those of the IPCC, i.e. (perhaps for all their intents and purposes) virtually non-existent – could spot a citation error all by themselves.

        Evidently not! From p.21 (of version 3)

        A comprehensive study of trends in storminess, for the period 1871-2010 from an ensemble of reanalyses by Wang et al. (2013)15 provides some important insights.[emphasis added -hro]

        But Footnote 15 begins:

        Wang et al. 2012: Trends and low frequency variability …

        Yet in version 1, this same very same text was cited and referenced as Footnote 12.

        And if they can’t be trusted on the small stuff, why should anyone trust ‘em on the big stuff, eh?!

  14. In the UKCP09 sea level projections, the central estimates (50th percentile) for SLR in the English Channel for 2010 to 2030 are 6.28cm for the SRES B1 (“Low”) scenario, and 8.78cm for the SRES A1FI (“High”) scenario. So linearly interpolating this to 2014-2030 (not strictly correct but close enough), the “further rise” by 2030 from now is projected to be about 5-7cm

    The numbers above include isostatic adjustment, and were worked out for me by a colleague today – they are close to those for London in Table 2 of the UKCP09 sea level report cited in the Met Office report.

    NB These don’t represent the full uncertainty range – see Figure 1.3 of the UKCP09 sea level report for the 5th & 95th percentiles of the projections. However, I’ve quoted the 50th percentiles because those were the post-1990 numbers given in the Met Office report.

    • Thanks Richard, that makes the source of the numbers very clear.

      An SLR of 5-7 cm between now and 2030 looks very like my and Paul M’s estimates (above) of 5 or 6 cm based on IPCC projections, being about 3 to 4 mm per year. I’m glad the Met Office and the IPCC agree.

      The Newlyn sea level, however, has been very steadily increasing by ~1.7 mm per year as in the plot above (which would be about 3 cm from 2014 to 2030). It will have to accelerate to reach 5 cm by 2030. (And unlike London, Newlyn is (arguably) in the English Channel). We’ll see. I hope to update this post in 2030 :-)

  15. I realise that I’ve left a comment hanging above. So to round this off, here are my thoughts on the matter. It’s not that I think the original mistake was deliberate – far from it. Clearly it was an honest mistake, which was rapidly corrected and a new version of the report posted promptly, which is to the credit of the Met Office (though I wish the Met Office would remove the old version or label it as such on their website, as it is still causing confusion).

    I did feel ‘deeply disturbed’ when I wrote that comment but have subsided to ‘very concerned’. And it’s not because I want to cast doubt on ‘the science’ but because I very much want to believe what I’m told by the official scientific bodies of this country. I do not want to wonder whether I can trust the numbers that the Met Office puts out (‘These numbers represent our current best estimate for the UK.’) and are quoted by others around the world.

    The paragraphs on sea level were by no means central to the report, which was on the recent (2014) floods and storms – there was clearly no intention to move sea level rise to centre stage. When I asked my question I expected either to be quickly informed that I had misunderstood something or pointed to a reference that made everything clear, or maybe to find that a simple typo or misstatement explained the matter. However the new version of the report appears to show that there was a genuine misunderstanding on the part of the authors of the paragraphs on sea level rise. I’m somewhat concerned about the original mistake, but mistakes of course happen. I’m much more concerned that it was not picked up by any of the distinguished authors of the report who presumably approved it – it was in the summary on page 2, as well as on page 21, nor by the many who uncritically repeated it.

    Looking again at the components of the original paragraph on page 2:

    Sea level along the English Channel has already risen by about 12cm in the last 100 years. With the warming we are already committed to over the next few decades, a further 11-16cm of sea level rise is likely by 2030. This equates to 23-27cm (9-10½ inches) of total sea level rise since 1900.

    This paragraph clearly compares 12 cm in 100 years with a further 11-16 cm … over what period? I read it as from 2014 to 2030 – and I’m far from alone in that reading – though the following sentence suggests some ambiguity about the dates. Sea level rise of 12 cm in 100 years versus 11-16 cm in 16 years implies a 6-to-8-fold acceleration by 2030 – which has so far not happened. Did none of the authors have a visceral feel for what those numbers implied? The paragraph leapt out at me as if someone had reported a 20 foot kitten.

    So – if it did not mean that – what did the paragraph mean? As the new version makes clear, the 12 cm in 100 years along the English Channel did not include isostatic adjustment (sinking of southern Britain as the north has risen since the last Ice Age) and so considerably understated the overall sea level rise around southern England over the 20th century. However, the 11-16 cm (which turns out to be the UK Climate Impacts Programme’s projection for London, 1990 to 2030), did include this adjustment. You simply can’t add together two different metrics, for different places, with overlapping timescales, and say that the result is meaningful. But this is what the report seemed to do (although the arithmetic is not exact) to give the overall sea level rise for the English Channel. This is why it seems to me that the numbers were not completely understood by the report’s authors.

    Anyway, the revised report did away with the addition of the two numbers, and also made clear that ‘the last 100 years’ meant ‘the 20th century’. But wouldn’t it have been more useful to compare overall UK sea level rise (including isostatic adjustment) over the last century (i.e. what the tide gauges measure) with the same metric for this century? Compare apples with apples as it were, using the actual policy-relevant metric? Instead, we see the minimum change to the report that ensures it is not actually wrong, but which still compares two quite different metrics with overlapping time periods, still giving the impression of accelerating sea level rise, when comparable metrics are available.

    The report could avoid the problem altogether by including just the final part of the paragraph on p.21, and omit the problematic projections – the following is a statement with which I think most people would agree:

    We are very confident that sea level will continue to rise over coming decades as the planet continues to warm. Clearly sea level rise from whatever source has to be factored into discussions about resilience to coastal and river inundations.

    Finally, while I do think that the Met Office moved quickly to produce a new version of the report, I cannot understand their attitude to version control (see also Hilary Ostrov’s comment above). Both versions of the report remain on the Met Office website, and a Google search for links to the old report produces far more hits than for the new one. It is still being shared widely. There is no indication on the pdf of either version that it has been revised, so the casual reader has absolutely no idea which version they are reading, or even that there are two versions. The Met Office should remove the old version from its website, and redirect readers to the new version.

    Why does any of this matter? Sea level rise isn’t the focus of the report, after all. But these numbers are probably the most widely quoted numbers in the report – they provide an easily-understood graphic impression of apparently rapidly accelerating sea level rise: an impression which is incorrect for the period under discussion. If the Met Office wants to be trusted on big issues, they need to demonstrate trustworthiness on issues such as this.

  16. I find that the link to the Australian in my comment above leads to a paywall – I had not realised that as I reached it via a google search. The article says:

    The Met Office said rising sea levels would increase the risk of flooding. It added that the level had risen along the English Channel by 12cm in the past 100 years and “with the warming we are already committed to over the next few decades, a further 11-16cm of sea level rise is likely by 2030”.

    Dame Julia said: “That might not sound a lot, but when you are looking at storm surges, when you are looking at moving water from the Somerset Levels out to sea, it does matter”.

  17. Pingback: Met Office spurious sea level claim | Deadal Earth

    • Considering the Met Office’s past practice of “passive promotion” of that which they know to be untrue, I am not in the least surprised. See, for example, the long lingering and misleading Marcott headline – evidence of which they subsequently “disappeared”, as they have done with their “update” version of the still extant erroneous and misleading text in this latest hasty pudding.

      It seems that the last time Richard Betts paid a visit to this corner of your garden pond, Ruth, was Feb. 13. This was after Jonathan’s February 11, 2014 at 6:45 am critique which he began as follows:

      Richard Betts,

      It is good of you to comment here and to bring news of this update, but are you really happy with this mealy mouthed and misleading change?

      There are several things badly wrong with this response. The first thing is the complete failure to acknowledge the original error or the fact that it has been corrected. I see that the pdf has been changed, but there is no note in the pdf to this effect, and there is no note on the html page. Similarly the choice of words in the revised text is deeply obfuscatory, and seems almost designed to confuse: “a further overall 11-16cm of sea level rise is likely by 2030, relative to 1990″ is self contradictory drivel. [emphasis added -hro]

      There are some individuals from whom one learns so much more from that to which they choose not to respond than from that to which they do. In observing the posting pattern of Richard Betts over the years, some might conclude that he is just such an individual. But I couldn’t possibly comment ;-)

      • Thanks for your comment, Hilary, and I agree with many of your points. But I’d like to defend Richard on this – he wasn’t an author of the Met Office report, but he did draw my question to the attention of the authors and the report was changed very quickly as a result. Not in the way that we might have liked, perhaps, but Richard was not responsible for that, nor has he tried to defend it. He was also on leave this week as it’s half-term!

  18. Pingback: Met Office storm final briefing – good, bad and ugly | Energy Matters

  19. Ruth,
    Your research is to be commended, along with Richard Betts for bringing the matter to the attention of the authors. We have gone from an apparent 700% acceleration in the rate of sea level rise, to absolutely zero compared with the global average of 3.2mm +/- 0.4 per annum for the last 20 years. Over 40 years that is 11.2mm to 14.4mm compared with the Met Offices estimate of 11-16cm. What they have done with some of the best computing power is equivalent to a forecast I could do on a calculator in two minutes. That is to assume that the local tide gauges will catch up with the satellite data. It makes sense if you assume that the satellites are accurate.

    Figures are at http://sealevel.colorado.edu/

    • Thank you! Unlike Canute I’ve managed to prevent the rate of SLR accelerating (not!). Though it seems the Met Office didn’t even do their own calculations, but – as far as I can see – just pulled two quite different metrics off the internet (Wahl et al. 2013 for the 20th century (not including glacial rebound) and UKCP09 for 1990 to 2030 (including glacial rebound)). Then they apparently misunderstood these numbers so badly that they thought they could add them together – and have now had to back-track a bit, reaching, as you say, pretty much the expected number.

  20. Warwick Hughes: “I remember Dr Kear as Director of the NZ Geological Survey when I was at University in the early 1960′s – hence my interest in his article now.”
    http://www.warwickhughes.com/blog/?p=2859

    Below are pertinent excerpts for TGP.

    Most interest then was about the rate of sea level rise as the Earth warmed following the “Little Ice Age”. That cool period, from about 1500 to 1700 AD, halted wine- making in England and taro cropping in New Zealand. Our Group determined the rate of sea level rise in many different World regions, from widely-available readings of tide gauges (less variable than those of thermometers). The average for us all was 125 mm/century (“125” here). Hence it would take 8 centuries for sea level to rise 1m – no serious threat to us.

    That rate of rise was equivalent to 3,500 mm/century, 28 times faster than our 125. Hence we stupidly ignored it, thinking no- one could possibly believe it. But the World did believe, and the Global Warming mirage was born. Had 3,500 been true, sea level should have risen by almost 1 m by today – it hasn’t, not even closely.

    Australian government scientists were concerned about the effects on Pacific Island nations by any sea level rise of around 3,500 mm/century, and launched a project to determine the correct figure at that time. They announced the result at the 1992 meeting of SOPAC – a geoscientific organisation of South Pacific nations. Their figure was 122 mm/century, confirming the order of magnitude of our group’s 125 average value.

    So did the Met Office actually check?
    Or is this the oxymoron local global?

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