Jim Renwick on the state of climate science

I have been listening to a lecture by Victoria University climate scientist, James Renwick, who has recently moved to the university from his post as principal climate scientist at NIWA.  In the seminar he sets out in broad terms some of the latest developments in the science. It’s a very clear summation, with some recent interesting graphs and charts, showing the direction which in which climate change is continuing to move. Needless to say there’s no change in direction apparent. I recommend the lecture as well worth listening to. I’ll only touch lightly in this post on the scientific content of the lecture; my main purpose is to highlight comments Renwick made along the way indicating the concern he feels about where we are headed.

I was particularly struck by an early statement made after he had remarked on the 2011 emissions reaching a record level of 31.6Gt and pointed to the graph of steadily increasing concentration of CO2 measured at Mauna Loa. I’ve transcribed it:

I feel a kind of morbid fascination with this stuff. It’s a really fascinating science issue – and I’m really  interested to  find out what’s going to happen to the climate and how much ice is going to melt and what’s the temperature in 2020 going to be and all the rest of it.  It’s intriguing, it’s my bread and butter but you know what I feel is – I look at this and say jeez we’re really doing this, we’re doing this experiment, we’re really playing this game with the Earth, we’re gambling with millions of lives and I sort of feel disgusted with myself that I find it interesting from a scientific point of view   It’s certainly interesting, but it’s more than interesting — it’s a very dangerous game we’re playing.

Just how dangerous becomes all too apparent as he proceeds. Global temperatures are continuing their steady increase from since around 1970. Sea levels are steadily rising, with the NZ rise similar to the current global mean of 3 mm per annum, roughly double that of the early 20 century. There’s an interesting comment on the temporary drop in sea level rise in 2010 and 2011 considered due partly to the La Niña event but also probably partly to the transfer of water in heavy rains, which he identifies as one of the new things around understanding sea level rise.

Ice is continuing to melt both in glaciers and in the Greenland and Antarctic ice sheets. Information about the ice sheets is improving considerably, including the mapping of ice movement. We don’t know enough yet to understand all the implications for sea level rise, but we’re getting there. He refers to a recent paper suggesting that we may be only a degree or so away from the temperature rise which could get the Greenland ice sheet moving irreversibly. The decline in Arctic sea ice in both the extent and the age of ice he describes as “fascinating in a bad kind of way”.

Renwick points to research suggesting that if we can halve emissions by 2050 then there’s more than a 50% chance of “staying below that 2 degree warming line which everyone appears to think, at a policy level at least, is a good thing to do”. He doesn’t explicitly say so but that two degree boundary is hardly established as safe by any science I have seen, and perhaps the terms in which he characterises the warming line are indicative of that. In any case as the lecture proceeds he recognises the possibility that we might be looking at a 4 degree rather than a 2 degree rise.

On rainfall attribution Renwick notes that model trends in all latitude bands are proving much weaker than observed trends. So things are changing in the direction we might expect but they’re actually changing faster than the models might tell us.

After covering such matters as the widening of the tropical belt by about 3 degrees latitude since 1980, the contraction of the Southern Annular Mode (the westerlies) toward the pole and the likelihood that 1 in 20-year warm periods are likely to become 1 in 2 years, Renwick moves to the implications for political action in the light of the fact that 2 degrees of warming is now virtually certain and that in fact we might be looking at more like 4 degrees:

“…which is extremely risky – large changes to the climate system, large changes to where the rain falls and how much, and food production and sea level rise.  Big stakes I must say, but some massive opportunities to do something good and to even make money if you can come up with some clean and green ideas that will sell.  But to me there still isn’t really the political leadership there to actually make things happen, which is quite concerning… We don’t have a conception of intergenerational debt, stewardship and all that kind of thing …We’re borrowing the earth against future generations and the earth is staring to bite back.”

I listened to the lecture mainly for its interesting presentation of the advances in the scientific understanding of climate change in the years since the last IPCC report, but the two extracts I’ve transcribed are also valuable for the way they communicate the human concern that accompanies the science. It’s not delivered in ringing tones, but it’s recognisable and surely appropriate. Moreover Renwick is voicing a level of disquiet widespread among climate scientists.

What is unfolding is deeply threatening to human life and the failure to address it adequately at the political level raises disturbing questions about our capacity to act ethically as societies. For climate change is at base now an ethical question. It is to do with the way our actions impact on the lives of others both now and in generations to come. And remedial action is not beyond our control. The ball is in the policy makers’ court. We should keep insisting that they address the issue adequately and with full seriousness.

36 thoughts on “Jim Renwick on the state of climate science”

  1. I think you’ll find that even biologists studying critters on their path to extinction, have a hard time reconciling the evidence before their eyes with an inner belief that this can’t be happening. For instance, some scientists studying the Great Barrier Reef (GBR) appear in the media suggesting their management of the reef is helping it recover, even when their own work shows total coral cover on the GBR continuing its inexorable decline. So, within that context it’s refreshing to read that Renwick calls a climate spade, a spade. Maybe it’s time to stop digging?

  2. I watched it OK in the weekend, watched it in shifts on a Macbook and our iMac but going in now, the lecture won’t load and run for me

    I’ve found the Mediasite stuff erratic in the past – I have had to load a plugin.

  3. I didn’t have a problem watching it – but that video is truly awful! Glitch after glitch; I ended up having to generate an Explorer window to cover it over and just have the presentation itself visible…

    1. Delving into the Help link on the page brings up advice on viewing with a Mac. Apparently we need Safari 2.0.4 or later (3.0.4 or later recommended) Firefox 2.0 or later plus the Silverlight plug-in.

      I’m running Safari 5.1.7 and have Silverlight…. it still doesn’t work.
      The final gem of info is “Contact your Mediasite administrator to make sure that HTTP streaming is enabled on the media server on port 80.”
      How the f**k do we do that?

        1. Yeah, or use Vimeo and tweak to your heart’s content! Why you’d bother to use one of these obscure formats is beyond my comprehension, particularly if your institution is supposed to be all about communicating…

          And, folks? Fix the camera! 🙂

      1. You dug out the right details. Fact is it doesn’t seem to be running now, and it was fine a couple of days ago.

        Yeah, the video element is not great quality, Bill, but the slides are fine! 🙂

        I’ve tried to view other things in the past with Mediasite, and have had quite mixed experiences. I’ve had the same as this too – a talk will work on a couple of occasions, then won’t run on later attempts.

  4. I got it working on my Vista and Windoze 7 machines, but it won’t run on my Windoze server or Macs.

    Oh for the days when universities were run by academics with Macs, rather than by accountants who buy the cheapest crap they can count beans on…

  5. The strange thing for me is that the lecture ran fine on 2 different machines, then a couple of days later wouldn’t run on either. Guess I’m glad I could see it at all!

    I don’t have a high opinion of that software from previous experience.

  6. Kevin Andersen at the Tyndall Center is saying “that ship has sailed” in regards to 2 degrees.

    He says the Tyndall Centre has evaluated “all” studies that claim it is possible at some moderate cost to keep the planetary temperature below 2 degrees and found them to be inaccurate, i.e. based on impossible assumptions, fudged data, and especially on ignoring what’s happening in China and India. The problem is only so much more carbon can be put into the atmosphere if 2 degrees is the limit, and the rates of CO2 reduction necessary to achieve this now haven’t even been considered in studies they are so drastic. The collapse of the heavy industry in the former Soviet Union as it dissolved didn’t achieve the rate of CO2 reduction now required.

    “I think the climate scientific community has hugely underplayed the size of the problem, knowingly, because its very hard to come up and say what you really think, because people don’t want to hear the message”.

    I was unable to get the Jim Renwick lecture going, perhaps because I’m using Chrome not Firefox or IE. But your description of it leads me to wonder what Jim would think of Anderson.

    Anderson is claiming there is a “widespread view” among top flight scientists that civilization is committed as of now to beyond 4 degrees, changes which will prove to be “incompatible with an organized global community”, “likely to be beyond adaptation… devastating to the majority of ecosystems”, and which have a “probability of not being stable”, i.e. the system will be experiencing positive feedbacks forcing it to warm even further no matter what emissions are like at that point.

    Anderson audio with slides is here.

    Are we going to pretend this isn’t happening and still keep telling ourselves and everyone else all we’d have to do is reduce emissions by 50% by 2050 and we’ll stay below 2 degrees and live happily ever after?

    Anderson: “…this is not a message of futility, but a wake-up call of where our rose-tinted spectacles have brought us. Real hope, if it is to arise at all, will do so from a bare assessment of the scale of the challenge we now face”

    1. All I can say about your post is, I agree.

      Technically it is possible to stay below 2C, our efforts so far exclude this possibility.
      With the upheaval over the coming decades caused by our inaction I wonder what I can do to prepare…

  7. The wait is over…. after Muellers latest paper on temperature data and trends Mr. Watts started digging himself….
    He ‘published’ a ‘Paper’ himself, fiddling with the temperature data, and presto finds less warming…
    Now his ‘Paper’ of which is calls himself the ‘Lead Author’ is self published as a ‘Web Release’….
    Surely we will shortly see some peer reviews coming in.
    In the meantime we can observe Watts digging down further….

      1. Perhaps, Andy, because Muller is a genuine scientist who has put his paper in for peer-review, whereas Watts is a failed meteorologist who just pulls stuff out of his derriere?

        1. Do you also think the same of the co-authors of the ‘paper’ namely Dr John Christy, Steve McIntyre, etc.
          Perhaps you’d also like to comment on Roger Pielke Sr’s comments on the ‘paper’

          Since Mullers conclusions depend in part on the station quality in the US temperature record, I would have thought that Watt’s ‘paper’ was relevant to Muller’s paper.

    1. I don’t see McIntyre running from anything. he is merely stating that he wished he had more time to review the paper before it was rushed into (pre-)publication.

      The WP article treats the Muller paper with the same criticism as the Watts one, yet you fail to mention that Thomas.

      1. BEST just reconfirms what we new already. But the ‘reformed skeptic’ meme is a media winner.

        Anthony’s little would-be distraction from it, on the other hand, demonstrates the defining characteristic of the fanatic – if what you’re doing doesn’t work just try again harder. It is a complete squib.

        Deniers now face a stark choice: follow Watts, and their instincts, into being perennial – and increasingly irrelevant – Tea Party style nutters permanently lost in Epistemic Closure World, becoming the Creationists of the 21st Century; or face the humiliating acceptance that the cause is lost and find something more useful to do with their time than being wrong about the single most important thing not to get wrong in the 21st Century. Given the damge they’ve already caused a lifetime of actively trying to rectify it would seem an appropriate – if scarcely adequate – atonement.

        But the latter option requires a strength of character that Deniers are the last people likely to display. So more attempted wrecking and whining irrelevance it is, then…

        1. BEST results are announced, for what they’re worth, Watts then croaks “squirrel” and all the Noddies do his bidding.
          You couldn’t script a more predicable comedy.

      2. Andys: “I don’t see McIntyre running from anything…”

        Yet McIntyre says:

        “People have quite reasonably asked about my connection with the surface stations article, given my puzzlement at Anthony’s announcement last week.”

        And then McIntyre goes on to further demolish Watts with:

        ” The satellite data seems quite convincing to me over the past 30 years and bounds the potential impact of contamination of surface stations, a point made in a CA post on Berkeley last fall here. Prior to the satellite period, station histories are “proxies” of varying quality. Over the continental US, the UAH satellite record shows a trend of 0.29 deg C/decade”

        McIntyre’s full “reflections” on Watt’s “paper” here: http://climateaudit.org/2012/07/31/surface-stations/
        Let the readers decide what McIntyre thinks about Watt’s “paper” and him being waved by Watts as “co-author” of that paper, much to McIntyr’s “puzzlement”…

        Ouch I say, and Watts reputation seems to be sinking even within his inner circle of “co-authors”….

        Sometimes the rats have a better sense about the prospect of a ships future buoyancy than the master…. at least that’s the lore of the seafarers…

        1. So McIntyre is now on “your side” now that he appears to be operating in a transparent and open manner that supports your “cause”?

          Were you gunning for McIntyre when he took apart Mann’s Hockey Stick? Were you gunning for McIntyre when he and his team took apart Gergis et al?

          Were you gunning for McIntyre after he was thanked by David Karoly for his work on Gergis et al and then subsequently dissed McIntyre in the Australian Book Review?

          1. McIntyre never “took apart” the hockey stick. He and his supporters claim that he did – but that’s neither true or on topic. What happens to Gergis et al remains to be seen. That’s off-topic too.

            1. It may be off-topic, but then surely the Watts et al paper is too.

              I didn’t bring this up, Thomas did

            2. No doubt the Gergis paper is largely correct, but likely exaggerates the warmth further back in time. This is inconsistent with the global sea level trend – it was static apart from a rising trend in the Atlantic ( due to post glacial forebulge subsidence combined with a warming Atlantic Ocean).

              The sea level trend quashes the myth of a globally warm Medieval Period.

              On the other hand, the 1.5°C of planet-wide warming since pre-industrial championed by Richard Mulller & BEST provides a better fit with the observations, and goes a long way to explaining why sea level rise in the 20th century was anomalous within the context of the last 7-8000 years.

          2. Andy: McIntyre has never been “on my side”. I simply point out to you and the readers his obvious annoyance with his com-padre Watts and the wee issue this raises for Watts….
            His distancing himself from Watts in this matter is certainly not hurting whatever credibility McIntyre may have left in the field. It leaves Watts in a bit of a pickle though don’t you agree?
            Lets await the announced new post by Gareth on the shebang then….

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