18
Aug
09

The doc says: “You got a problem!”

Neat letter to the Sydney Morning Herald (Aug 17):

I’m not a climate scientist per se, but I am a senior Australian scientist (biologist) with interests and expertise in environmental science. Reading Miranda Devine’s piece ( ”Bring it on, Labor, pull that trigger”, August 15-16), it occurred to me that in the climate change debate there are serious misconceptions about the way science actually works. So let’s shift the context from climate change to medicine.

Your health declines. You see 10 specialists and nine tell you that you have a serious, complex medical condition that requires surgery.

The 10th says you are fine and there is no need to do anything. You follow the advice of the 10th and do nothing for a year. Your health does not improve. You go back to see the specialists, and nine tell you that the condition is worse and you need the surgery urgently. The 10th still says you don’t need to do anything and in fact argues that the condition is not real. What would you do?

This is exactly the state of play in climate science. The vast majority of specialists in the field say we have a major problem, that it is caused by humans, and it is probably getting worse. This is not the same as ”proof”. It is difficult if not impossible to ”prove” complex environmental (or many other) scientific theories. Climate change science is not a high school geometry problem.

Instead what happens is that evidence is gathered that supports a theory, alternative explanations are considered and discounted on the evidence, and a consensus view emerges. As a consequence of this process the overall consensus on human-induced climate change is now quite strong among experts in the field. Thus comments by Senator Fielding or others of like mind who deny climate change, or the need for us to act, on the basis that ”the science is unproven” or ”science does not work by consensus” are misleading. They do not reflect how most science actually works.

I suspect my comments may actually be used to argue against the reality of climate change (”Senior scientist says climate change not proven!”). In response I go back to my parable. Your health or even your life is on the line and nine of 10 specialists propose a diagnosis and subsequent course of action. What would you do?

Professor Peter Steinberg Mosman

It’s a good analogy I think. It makes me stand back and think, I might want to believe the advice of the tenth specialist. But it’s my health, and I’ll act if I need to.

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16
Aug
09

Cooling on Plimer

So the Plimer/Monbiot ‘wrestle’ is off to bumpy start.

Before jumping in, just a brief word about George Monbiot, since I had an explore of Ian Plimer in a previous post. Monbiot is a journalist, not a scientist, and quick to say so. He is lower on the credibility spectrum than Plimer (who himself is among the science community, but not a specialist in climate study). So you don’t trust what he says on his own authority. Nor is that his aim – he says he aims to clearly communicate what he comes across from climate experts. Nothing wrong with that – it is how cultural communication takes place. But he does come from a particular political persuasion – he has always been connected with protest movements, even having been involved with the Respect party in the UK. He has a worldview that comes to the fore in what he writes. As with Plimer, we should see the worldview behind the arguments, but still judge the arguments for their truth and coherence.

Pre-fight

Plimer writes a book, critiquing climate science findings.

Monbiot reports criticism of the book and adds his own summary.

Plimer challenges Monbiot to debate the science. (I can’t find a primary source for that from Plimer, but Monbiot’s one-sided account is here.)

Monbiot originally turned down the challenge, but then accepted it, with a condition: that as well as a live debate there would also be a written, on-line debate, so that references could be checked and arguments could be parsed more slowly, point by point.

Plimer originally turned down that challenge, but then accepted it.

Round 1

Monbiot posed 11 questions.

Round… 1a

Plimer responded with 13 questions.

On the surface it sounds fair, although it would have been good to see Plimer’s answers at the same time as he raised questions. But let’s have a look at the kind of questions, and the kind of answers they are looking for. To do that, I’ll drop out the detail of the questions and look at their form.

Monbiot’s questions

  1. You make a claim of temperature dropping based on data from HadCRUT (measuring the world climate). But the data says otherwise. What gives? How did you calculate a different outcome?
  2. There is an important graph in your book with no source. What is the source? Who’s figures are they?
  3. You make this important claim without a reference. What is your source?
  4. You seem to make a claim about global temperature based on data for the USA alone. What gives? Did you mean to?
  5. You make a claim without a reference. What is your source? Your claim seems to contradict evidence. What gives?
  6. You make a claim without a reference. What is your source?
  7. Your claim about water vapour is without a reference, and seems to lead to nonsense results. What gives, and what’s your source?
  8. You seem to have misrepresented a scientific paper, getting opposite implications. What gives?
  9. You provide no reference for a claim that seems to stand against what a body says about its own work. What gives? What is your reference?
  10. You make a claim without a reference. What is your source?
  11. You make a claim without a reference. What is your source?

You can see the pattern. Generally, something you have written which is not referenced. Please provide the reference so that it can be tested. More strongly, without the reference, the claim is just an assertion with little value as a claim to truth.

Now, Plimer’s questions. Well, I was about to start, but they aren’t really questions. They are tasks. Plimer has set a series of tasks.

  1. Use several data sources to propose past earth temperatures. Show all calculations and justify your assumptions.
  2. Calculate gas results from a large group of volcanic sources… Reference and justify all assumptions.
  3. From first principles, calculate… Justify all assumptions.
  4. Calculate the changes in… Justify all assumptions.
  5. Calculate forcings of temperature … Justify all assumptions and show all calculations.
  6. From a large range of data, demonstrate numerically that…

Look, I’m not going to continue. You can see the pattern.

The two sets of questions (and you really should go and take a look at Plimer’s!) have very different qualities. Plimer wins the prize for ‘sciencey’ sounding questions. But that misses the point. Monbiot’s were sharp and focussed. Most could be answered in a line or two, some would need a couple of paragraphs. Plimers are 13 research projects. I’m trying to be fair and open to debate, but that is just silly. It makes Plimer seem like a self-important prat. Maybe he isn’t.

Monbiot says that he is simply not the person to address the questions. Fair enough, he is a journalist. Interestingly, there is a group of scientists who have set up a project to respond to the Plimer questions. Maybe that is a good thing, as at least it could get the debate going. I hope that Plimer gets his team together to answer the simple reference questions. Then we will be getting somewhere!

09
Aug
09

Plimer’s position in public debate

Whatever you think of Ian Plimer’s book Heaven and Earth, you’ve got to admit that the good doctor puts himself in some interesting spots in public debate. He came onto my radar in the 1980s as an outspoken critic of creationism. If a creationist delegation wanted to debate the ‘science’ of their position, Plimer would step up to the plate. There was a colourful discourse (it wasn’t really a debate) between Plimer and a creationist named Duane Gish held in Sydney in 1988. There is a series of 16 clips, and you catch some of the Plimer style here…

Here he is speaking against what mainstream science would regard as a pseudo-science. Most of the scientific community would have put their voice on the same side, if not with the same rhetoric.

Now 20 years later, curiously, he places himself against the broad scientific point of view with regard to the causes of global warming. You can see clips from one of his talks here.
And he is finding himself the target of the same kind of critique as he dished out himself in earlier times. (I’m sure he wouldn’t consider it the same kind of critique!)

Interesting. He is somebody attracted to putting forward contrary positions. How does he make sense of his two apparently contrasting opponents? Well, he brings them both together by saying that the Global Warming movement is a new fundamentalist religion:

Here’s one thread of discussion I’ll be following up on. George Monbiot has challenged Ian Plimer to two debates – one live, and one on-line by discussion of a short series of focussed questions. It’s those questions I’ll be watching, as they are very clear, and it should be easy enough to see if the answers are direct, or evasive. Stay tuned.

05
Aug
09

the hockey stick graph #1

Here we go.

300px-Hockey_stick_chart_ipcc_large

For now we don’t need more detail than this overall view. It is the graph made famous by Al Gore’s An Inconvenient Truth. It was also a defining feature of the IPCC 2001 climate report.

Why is it such a big deal? I think it is because it tells such a clear and simple story. It says:

over the past millennium the global climate has been pretty stable… until about a hundred years ago. Since then it has shot up well above levels seen in more than 1000 years. It represents the best of scientific knowledge, a consensus among world leaders in this field of study.

The audience of this message became… everyone.

It turns out that things aren’t so simple. The graph is inaccurate. That was proposed by Stephen McIntyre and Ross McKitrick.

Before we start to look at the arguments for or against the graph, let’s see how the critique is framed. McIntyre uses a model that positions the hockey stick graph: the Bre-X fraud of the 1990s. The Bre-X fraud was the biggest mining scandal of all time. Briefly (and sorry for the simplification), a mining company reported that it was sitting on the biggest gold deposit ever found, at a site in Indonesia. An independent company estimated the the apparently huge resource, and the share price shot up. Could $20million exploration investment, 2 years work by 15 geologists and 7 drill rigs be wrong? Few were skeptical. But eventually the fraud became clear and the stock crashed. Now the model of Bre-X is not used directly – he is not saying that the hockey stick represents fraud. Rather, it is simply juxtaposed: see, this kind of thing happens, in our world, in our time. Don’t be fooled again – check before you invest!

That’s the way we build project paradigm – the mental model keeps the project on target. Which is interesting to keep in mind as over future posts we look through the comings and goings of the debate over the graph.

The other way I’d like to frame the exploration is through the story that the graph tells. There is double potency in that simple story, presented by an authoritative group. It is potent because it can convey a message very powerfully to a wide public (as it has). However, the other side of that potency is the strength of disillusionment that it makes possible. It becomes a powerful skeptical weapon if doubt is cast on the science behind it. The big message for a skeptical public can be:

if the scientists can’t be trusted with such a simple message as this, how can they be trusted with the more difficult and subtle parts of the climate argument?

Hmm. We shall see.

04
Aug
09

plans

Well, I’ve been a bit quiet, because I’m planning what to work on. I’m realising that as I nose my way around the field I’m leaving subjects somewhat unexplored and unfinished. Well, not that anything is ever ‘finished’ – it’s more that it is a conversation in which there is more distance to travel.

So in part I’m just noting these down so that I don’t forget them.

I’m not forgetting that Senator Fielding asked 3 questions, and that I’ve only looked a little at one of them. I’m really interested in the whole area of the ancient climate. We move out of the realm of direct instrument measurements of temperature, and into the realm of estimates based on secondary evidence – tree rings, coral growth and so on. On the way back to the ancient past I’m interested in this whole idea of  a ‘medieval warm period’ and a ‘little ice age’. What were they all about?

Then there is the continuing look at the surfacestations project. I like this one because it is really very concrete (in contrast to the vagueries of paleoclimatology!) – the question of bringing together actual measurements from many stations, with their varying quality, and drawing a meaningful overall conclusion.

But at the same time I’m keen to take on another small piece of the subject, one that brings together the ancient climate and the recent measurements: the Hockey Stick. The (in)famous hockey stick, which kicked of the broad public awareness of climate issues through Al Gore’s movie and lecture tour.

According to global warming proponents, it represented the best combined knowledge of the time, and still gives a good picture of overall global changes. Critics of the climate change movement propose that the graph misrepresented the data, and is a poor representation of past temperature. It is such an iconic picture, I think it is worth an explore.

30
Jul
09

lack of grace in the climate debate

For today, just an observation on the tone of discussion. It often shows immaturity and lack of grace to one another. That probably makes the individuals dishing it out feel great and important. But it makes them look arrogant, small minded and, ultimately, stupid to the rest of us who aren’t ‘party members’ as it were.

The example that has caught my eye will be an old chestnut for long-time climate watchers, but is interesting to newcomers like me.

Anthony Watts is a blogger (now joined by some 10 contributers), a former meteorologist in California and a climate change sceptic. Weather is not global climate, but it is clearly a related field, so one can understand Watts being interested in the subject.

Now Watts, as a good meteorologist, is interested in the methods of reading local temperatures. He directed his scepticism of global readings of temperature at the methodology of the readings from around the USA. He inspected some of the official measuring stations and found that they were very close to human made features that may compromise the temperature readings. Some were practically within reach of air conditioning units, others were receiving reflected heat from large concreted surfaces. Watts co-opted volunteers to check weather stations all around the USA, and they reported back similar findings in many cases. The results were collated at http://www.surfacestations.org/. Here is a clear chart of their results:

So for 61% of the stations they looked at, the readings could be 5 degrees or more in error because of the micro environment in which the thermometer was situated. When you see photos like this, you can see why:

And there are lots of photos like that. It throws in doubt the temperature record for these stations.

As always, I won’t question the data crunching – that is a task I’m happy to leave to others. But on the surface this seems like a fair enough question: is the warming trend data compromised by the large proportion of ill-sited thermometers? My gut says yes of course it is.

It seems the answer is … no, the global surface measures are pretty dang good despite those stations.

The surfacestations group classed only some 70 measuring stations (fairly evenly peppered across the USA) as being of the highest quality. That is about 2% of stations. Sounds gloomy. So a test was done, comparing the results from only those stations with the readings from all stations (corrected as they have always been by an algorithm). The result:

No practical difference.

And here it is (same result) in video format by Peter Sinclair:

NOW HERE IS WHERE IT GETS INTERESTING.

Which side to start with. On the ‘warming’ side, both that video and the site you can click through to from the graph are … gloating, I think you could describe it as, in their ‘victory’. Hey, I’m with them on the data. Seems good. But hey, it was a good question, and a research project contributed to by a large grassroots group. A hypothesis: Poor measurement mechanisms compromise the data. Tested. Shown false. But don’t go s***ing on the group that did the work of setting up a good question. We were all doing reasonable science until then.

Ok. But Watts doesn’t have clean hands in this either. When the video went up, Watts complained to YouTube and had it taken down for infringing and/or circumventing copyrighted works. There’s a short clip from a movie up front. Was it that? Was it the interview with Watts? No call for the take-down, and soon enough it was back. But that wasn’t science either. It looked pretty bad.

Once again a case, from both sides of More Heat Than Light. Euf.

28
Jul
09

factoid: volcanoes

Ok, so this is the story that has been a part of my folklore: we humans think we are pretty big and bad and that we can do things to change the climate of the earth. But hey, if you want to see Big, look at a volcanic eruption – one of those will put more junk into the atmosphere than a whole year of human emissions. That sounds true, and there is part of me that wants to believe it – we are very self centred as a species. We think that the world revolves around us. It’s about time we respected the power of the Earth a little more. That’s the heart message of that factoid for me.

But what’s the evidence of the figures? Is it true?

So here is the sucker punch visualisation to that idea:

Remember again I’m not totally focused on the precise accuracy of the graphs, more the messages they give. Is that evil, not to care about accuracy? Well, yes, I guess it is. Accuracy is absolutely vital. But there is more to it – given accuracy in the data, there is still a world of storytelling in the way that data is presented. Tell me the figures are way off and we will see how that changes the story.

What’s Toba? It’s the biggest volcanic eruption in the last 100,000 years. And why is it there? Because here you can see that on its best day Toba couldn’t hold a candle to human emissions for a day:

So why is this factoid stuck in my consciousness? And in the consciousness of most everyone I’ve asked?

Here is a good story of the background. I haven’t retraced each step of his research, but it makes sense. Tell me it ain’t so. It runs like this:

In 1992 Rush Limbaugh wrote a book which claimed that

Mount Pinatubo in the Philippines spewed forth more than a thousand times the amount of ozone-depleting chemicals in one eruption than all the fluorocarbons manufactured by wicked, diabolical, and insensitive corporations in history.

Rush Limbaugh is an influential voice, and this idea gained currency among his audience, and got slightly changed and elaborated as it was heard and repeated.

And what of the claim itself? Well it relies on a book by Dixy Lee Ray, a marine biologist and former head of the USA Atomic Energy Commission. Only, Ray didn’t write about Mt Pinatubo – she wrote about Mt St Augustine, which erupted in 1976 in Alaska, saying it

injected 289 billion kilograms of hydrochloric acid directly into the stratosphere. That amount is 570 times the total world production of chlorine and fluorocarbon compounds in the year 1975.

Sounds impressive anyway. And what source did she rely on? She relied on a David Johnston paper. Only Johnston wasn’t talking about Mt St Augustine – he was writing about a volcano that formed the Long Valley Caldera in California 700,000 years ago. Now that volcano put out a lot of just about everything. If you had been around at that time I think you would have had more problems than calculating the CO2 output! Johnston did talk about Mt St Augustine, and estimated it put out 17 to 36 percent of 1975 world production of chlorine in CFCs. A significant amount, but still a contribution to a single year, not a continuous output, as in the case of humans.

Here is the magnitude of that error:

Now there’s an error of magnitude!

So it worked something like this:

volcano factoidSo that’s the story of how it got into my head, and maybe yours. Maybe that’s not all there is to the story? Maybe there is another one? That’s what I’m interested to hear!

Once more, another version of a factoid-killing visualisation:

Lastly, looking around this series of tubes that is the internet, this factoid is really a bit of a soft target. Skeptical people are not putting it high on the skepticism list, and if you look for the claim and counterclaim, you will mainly find sites loudly putting forth the fact that human emissions dwarf the volcanoes. That’s fine, and I’m glad, but I’m nonetheless fascinated that it has been such a persistent piece of background knowledge. It is a ‘sticky’ factoid.