Cat. Pigeons. Climate Change

Finally, I managed to get a letter into The Australian after many tries at arguing reasonably about the drivel that passes for debate about climate change that they publish on a regular basis.

It seems that polite doesn’t pay: strong words are what they are after. Could it be that the tactic many on the science side of the debate have been using of politely refuting the scientific inaccuracy of the other side is not the way to get editorial attention?

Here’s the letter and some responses to comments (since they don’t keep updating comments at the site).

DOUG Hurst (Letters, 26/6) tells us climate change isn’t always matched by changes in CO2. So what? No one claims that has to be the case except climate change deniers.

Every serious scientist working on climate science has absolutely no problem with acknowledging and taking into account a wide range of influences on climate. If Hurst wants anthropogenic carbon dioxide emissions to have been an influence on climate in the 14th century, good luck to him in finding an industrial society with the capacity to pollute on the scale that is happening today.

The argument that mainstream climate science is somehow invalidated because there is more than one driver of climate is completely bogus, and it’s time you stopped wasting space reprinting the same drivel. Repeated stating of obviously stupid arguments does not increase their plausibility.

Now my responses to comments (you’ll have to go to the Letters site to see the names):

• Perhaps rather than having written a romantic novel involving climate change, you could have written something factual – At least I know when I’m writing fiction (see sidebar, top right, for how to buy – thanks for the plug).
  
• The colourful climate change theories promoted by Al Gore, Tim Flannery et al are at the heart of the dire “carbon pollution” predictions that drive and apparently sustain bogus academic careers and the political positions of many ... A good number of us simply don’t enjoy being lied to and manipulated, and especially not by politicians. – What’s your evidence? I’ve put a lot of time and effort into studying the case that the science is bogus, and all of the lies and trickery are on the other side.
  
• Well surely then we are wasting a lot of effort on harnessing CO2 if it is not necessarily the cause? – It was not the cause of most climate variation in the past. That doesn’t mean it can’t be the cause today.
  
• Which is why we need more broadcasting of the deep flaws in the agw hypothesis. – Let’s hear them then. All I hear is talking points that are stupefyingly easy to shoot down.
  
• Thats just a bizarre statement! If there’s no link to CO2 and global warming then what the hell is the global warming industry on about with promoting a ETS? – I did not say that. I said that warming in the past was not caused by anthropogenic CO₂ emissions. I did not say anthropogenic CO₂ emissions are not causing warming now.
  
• Last time I checked the latest IPCC report these factors such as cloud albedo affect, and affect of aerosols were listed as having a low level of scientific understanding. Given this represents a high degree of uncertainty in our knowledge of the affect of these other forcing agents (of about 1.8Wm-2 or 113% of the calculation net Anthropogenic forcing)) and the low levels of warming expected from increases in CO2, arguably the precautionary principal supports a do nothing, or do very little response, until these factors are better understood – the warming since pre-industrial times is sufficient to be sure that these effects are well enough understood to have confidence in modelled predictions.
  
• The original theory is that emissions of man-made CO2 will cause global warming. That has not been proven. What evidence can you offer that the theory is correct? – A lot of scientific papers. But here’s one thing you can check yourself. If the sun is the sole driver of the climate then the temperature trend should closely track variations in solar output. That was true until the twentieth century when that relationship slowly changed. If you look at the last solar cycle, while it has been on a strong downward trend, temperatures have still been slowly increasing. The “paper” you point to at the Letters site claims: “If the climate feedbacks are as strongly positive as the ones programmed into the IPCC climate models...”. First, the IPCC does not do climate models; they report the work of others. Second, feedbacks are not built into these models. The feedbacks arise out of application of laws of physics and observational data. Calling people “warmists” assumes there is some sort of religion or political movement out there. There is not. There is the scientific mainstream, and there is a small group of dissenters, as in any mainstream field of science.
  
• Are you seriously defending Lovelock’s Revenge of Gaia’s dire predictions or saying they’re within an acceptable range of accuracy – his claims are at the outer end of probability but not impossible, especially if we do not slow down on CO₂ emissions. I do not agree with him that it’s too late to stop.
  
• Science says that nothing happens by chance – try studying quantum physics.
  
• That includes the theory that greenhouse gas is the prime cause – GHG is the prime human-controlled cause. No one says the solar cycle stopped when we started burning coal. It is this kind of argument that I claim is idiotic. Go and read the scientific literature, even IPCC reports (e.g. their report on attributing climate change) if you don’t have an academic library. Over the last 10 years, the solar cycle has turned to a strong cooling trend and that has not been reflected in the temperature trend. Tell me what else could have caused that.
  
• Perhaps then you’d like to explain how your hypothesis fits the fact that the Late Ordovician Period was also an ice age, while at the same time CO2 concentrations at about 4400 ppm were nearly 12 times higher than they are today – No problem. First, the continental configuration was so different to today’s that you have to be careful to make comparisons (this was over 400-million years ago). Bearing that in mind, an increase of 15 times in CO₂ levels is a bit less that 4 doublings, call that a 12°C increase. That increase is over whatever temperature you started with. With a large land mass over the south pole in this era, the conditions existed for a very big temperature drop as compared with today. The high CO₂ level reduced that temperature drop. The sun was also weaker then. For an even more extreme case, look up literature on snowball earth. For anything vaguely comparable to what is happening today, you need to look for an era with a rapid increase in GHG levels on top of a moderate climate. Look at what happened in the boundary between the Permian and Triassic for example (251 million years ago, so we still have to be careful to extrapolate to today’s conditions).
  
• The ‘debate’ on AGW will continue for as long as the believers ignore the sociological and quasi-theological underpinnings of their faith – in science, we argue on verifiable facts and testable theories. If you want to call this a religion etc. you’re confused. What’s you mode of argument? Easily debunked talking points? What do you call that?
  
• I repeat as previous - if C02 is not the total, primary what ever cause of climate change, why are we not addressing the lot, if there is any need to do anything other trhan find alternative cleaner sources of energy – CO₂ is the major human-caused effect on the climate. There is no evidence that anything else is varying the climate on a time scale that matters to human civilzation. The solar cycle is a cycle: it goes up and down. El Niña and La Niña are short-term effects.
  
• Does temperature control CO2 or vice versa? The Vostok ice core data shows rhythmic glacial - interglacial cycles of around 100,000 years duration over almost a million years back from the present interglacial. The IPCC proposes that the primary cyclical influence is orbital variability, which provokes temperature increase followed centuries later by CO2 increase (2007 Report, Chapter 6 page 444). The difference between the rationalists and IPCC alarmists is that IPCC concludes that CO2 then takes over as the primary forcing agent. – Drivel. The IPCC (or actually, the scientists they quote) never assume that in this scenario CO₂ is the primary forcing agent. In this scenario, CO₂ is a feedback. It is only a forcing if it is the initiator of the change, not a subsidiary effect. Anthropogenic CO₂ is a forcing because it adds to temperature change without being caused by some other temperature change. Over geological time, there have been periods when CO₂ was a forcing (e.g., when emitted as a result of plate tectonics or massive volcanoes, far bigger than any in human history).
  
• Peer-reviewed geological literature shows the peak of the current interglacial was around 6000 years ago with temperature around two degrees higher and sea level almost two metres higher than present. So in fact over the past 6000 years we have seen a cooling trend - But you wont read that in the IPCC reports. So much for drivel – The IPCC’s report on palaeoclimate says we are currently in period of low variability in orbital parameters, putting the onset of the next glacial at about 30,000 years. It’s not relevant whether we were or not on a cooling trend in the past. What’s your evidence that this trend is continuing?
  
• you basically defeat your own arguement. You argue that there are a number of other factors at play as well as CO2. This is exactly what the climate change realists have been saying for yonks – No they haven’t. The denial crew have been saying that CO₂ either has no effect, or is relatively insignificant. Mainstream scientists have never said that CO₂ is the only influence on the climate, only that it is the major one that humans can influence. And that there is very little chance that anything else of significance is happening on a time scale of significance to humanity.
  

In summary: this whole exercise illustrates what it’s all about. The denial (or inactivist) position tries to summarise climate science as alleging that CO₂ is the only influence on climate, then attacks this straw target vigorously, with ever-bigger bails of straw. The fact that CO₂ is not the only influence on climate is well known and well understood buy anyone who works with the science or follows it in scientific publications.

What about the volcanoes?

The Ian Plimer saga continues, with yet more articles in The Australian featuring his half-truths and attempts at politicizing climate science in the cause of selling his book.

Let’s just look at one more small sampling:

Some 85 per cent of volcanoes are unseen and unmeasured yet these heat the oceans and add monstrous amounts of CO2 to the oceans. Why have these been ignored? Why have there been five significant ice ages when CO2 was higher than now? Why were warmings in Minoan, Roman and medieval times natural, yet a smaller warming at the end of the 20th century was due to human activities? If climate changed at the end of the Little Ice Age (c.1850), is it unusual for warming to follow?

Computer models using the past 150 years of measurements have been used to predict climate for the next few centuries. Why have these models not been run backwards to validate known climate changes?

I would bet the farm that by running these models backwards, El Nino events and volcanoes such as Krakatoa (1883, 535), Rabaul (536) and Tambora (1815) could not be validated.

Let’s take his assertions one at a time.

• 85 per cent of volcanoes are unseen and unmeasured – so what? If this effect is not changing it is not part of any increase in atmospheric CO₂. There are massive fluxes in CO₂ between the atmosphere and the rest of the environment all the time. These fluxes at a period of stable climate are in balance. By adding an additional flux, we are pushing the climate to a new equilibrium state.
  
• Why have there been five significant ice ages when CO₂ was higher than now? – possibly because the other factors driving the climate at the time were different? How about checking paleoclimate research to investigate this question? The effect of a given level of CO₂ or other greenhouse gases on the climate has to be measured against other influences. No one claims CO₂ is the only influence on climate – except psueudo-sceptics like Plimer.
  
• Why were warmings in Minoan, Roman and medieval times natural, yet a smaller warming at the end of the 20th century was due to human activities? – the claim that these earlier warmings were greater than current warming is controversial but leave that aside because it’s irrelevant. What is relevant is whether something different is causing the warming now and whether that different thing is an ongoing effect that could result in a higher, dangerous level of warming. The other warmings were clearly not caused by anthropogenic greenhouse gas emissions because industry did not exist at those times on a scale that could have caused them. Any natural causes such as increased solar activity does not apply today. Continued CO₂ emissions will not stop of their own accord. This argument only makes sense (assuming he is right about the scale of previous warmings and that is doubtful) if Plimer is able to argue that CO₂-based warming will somehow be limited.
  
• If climate changed at the end of the Little Ice Age (c.1850), is it unusual for warming to follow? – so what? No one is arguing that there is no natural climate variation.
  
• Why have these models not been run backwards to validate known climate changes? They have. To assert otherwise is ignorant or dishonest.
  
• I would bet the farm that by running these models backwards, El Nino events and volcanoes such as (1883, 535), Rabaul (536) and Tambora (1815) could not be validated – what is he asking here? Does he want climate models to predict when volcanoes will happen and how large they are? It has been millions of years since a volcano big enough to cause more than a minor climate shift has happened. Krakatoa had an affect that is still measurable today but not so big as to cause problems with the general trend of climate models.
  

Overall, the points he raises are insubstantial and have no real bearing on the problem of anthropogenic climate change. If he has evidence to overturn this judgment, he should publish in the academic literature. Otherwise his claims are vacuous, just so much hot air.

The Australian and Postmodern Science

Saturday 18 April 2009 represented a new high or low point (depending on your perspective, which turns out to be significant) in The Australian’s project to develop a new postmodern science, in which “objective truth” depends totally on the observer, and deconstruction replaces evidence-based evaluation.

First, there was an article “Revealed: Antarctic ice growing, not shrinking”, which selectively quotes Australian Antarctic Division glaciology program head Ian Allison to create the impression that there is no warming in the Antarctic. In fact one of the major investigations in which the AAD is involved is into sea ice thickness, which they propose could be a more significant indicator of future ice loss than ice extent (the ice can thin for many years before it disappears, as happened with Arctic sea ice). The same author had another article, “Change is a cold certainty”, which despite spinning the position as the Antarctic is not warming, was reasonably balanced when you got to the detail.

Then, there were two opinion pieces about a new book, The climate of disastrous consensus, by geologist Ian Plimer. I will focus on the article that deals more directly with the content of the book, rather than the opinion piece by Christopher Pearson (there’s just so much one person with a day job can do). Here are some quotes from the article, which quotes the book directly, so I assume it is not misrepresented:

• CO₂ is not a pollutant but a necessity of life. For a start, it is food for plants. "Global warming and a high CO₂ content bring prosperity and lengthen your life ... without CO₂ there would be no complex life on Earth" – a silly statement. You can say the same about water, but not only can you drown in the stuff, but you can actually die from drinking too much water. Extra CO₂ makes plants grow faster, but not without limit, and there’s no guarantee that the plants of human interest will gain the most. What’s more, other effects of climate change like change in temperature and rainfall patterns are more significant to agriculture.
  
• While an increase in atmospheric carbon dioxide theoretically may contribute to temperature rise, Plimer says there is no evidence to show this and plenty of proof, if you choose to look for it, to the contrary – the evidence for this is very strong and is based on science that’s been known since the 19th century. To assert this in a newspaper article without providing Plimer’s evidence makes him look a fool.
  
• To reduce climate change to the single variable of carbon emissions abandons "all we know about planet Earth, the sun and the cosmos", Plimer says, and that is a leap of faith no self-respecting scientist should take – unmitigated drivel. No serious climate scientist models the entire system based on one variable. To see how absurd this claim is, you only need to do a google search on two keywords: “IPCC attribution”. I've included a graph typical of the approaches used (note the multiple influences included).
  
• When he peers back in time, there were periods when atmospheric CO₂ was much higher than it is now yet produced no disastrous shift in the climate – perhaps he’d care to point out what fraction of life on the planet dates from that era. More than 90% of species from eras when CO₂ was substantially higher than it is today are extinct. Four out of five mass extinction events are associated with rapid climate change.
  

The article goes on to an interview. Here are a few excerpts:

• He reviewed five computer predictions of climate made in 2000, underpinning IPCC findings, and found there was no relationship between predicted future temperature and actual measured temperature even during a short period – why would he expect the models and measurement to line up over a short period? To make such a supposition is to misunderstand the nature of climate science. There are very big day-to-day fluctuations in weather. Over a month, averages smooth these fluctuations out. Over a year, more so. Climate is about stepping back and looking at the long-term average. The current trend is for warming at a rate of 2°C per century, an average of 0.02°C per year. This small a change is not discernible over natural variation unless you look at a long enough stretch – which is why climate is generally looked at as an average over 30 years.
  
• There was alarm in the 1970s that the decreasing temperature was heralding another ice age, he says – this is standard propaganda from his side of politics. A 2008 paper has found that contrary to this often-repeated claim, papers published from 1965 to 1979 on climate change totalled 7 predicting cooling, 44 predicting warming and 20 that were neutral. That’s what we mean about “evidence” in the mainstream scientific community. We don’t take things as given because people we like are saying them: we check the facts.
  
• The ice caps are geologically unusual; people were growing barley and wheat in Greenland 1000 years ago. – Are we supposed to infer from that that Greenland’s ice cap is less than 1,000 years old? I can only suspect that the journalist has things garbled here. Plimer can’t be that ignorant. Ice core studies of Greenland go back over 100,000 years. It is very likely that Greenland and much of Europe was warmer 1,000 years ago, but there is no evidence that this warmth extended worldwide. If you check the temperature records of any location, there is a good chance you will find an unusually warm period. Do all such periods around the world line up at the same period? No, not over the last 1500 years, the era when the “Medieval Warm Period” and Little Ice Age occurred in Europe. Some places were warmer 1,500 years ago, others 1,000 years ago.

To accuse others of ignoring evidence creates an onus on you to examine evidence with extra care. Repeating often-debunked talking points does not qualify. Possibly The Australian has been very selective in its reading and picked out its favourite talking points. If they have misrepresented Plimer’s book, I hope to see a rebuttal from him. Failing which, I’m not going to read the book. I am from the old school of science, where the evidence is based on measurement, not on your political preconceptions.

Call me old fashioned, but I, unlike The Australian, don’t see a role for post-modernism in science. The old model of examining the evidence, developing hypotheses, testing them against new evidence until they look solid, then promoting them to theories works for me – as it has done for the creation of a robust industrial society. What a pity the same intellectual rigour does not apply to other areas of society – like running a newspaper.

Pumkin and rhubarb pie with Lime Mousse Ice Cream

In another of my rare forays into cuisine (for another, see my trick for making gelato), here is a crossover of my own creation: pumpkin and rhubarb pie. This makes 2 pies (20cm) or 4 smaller (10cm) ones.

Pie crust
4 cups flour
200 ml macadamia oil
2 teaspoons sugar
6 tablespoons chilled water

Mix the dry ingredients thoroughly then gradually incorporate the oil, adding a little extra four if necessary to get a crumbly texture. Add in the iced water as you go. Roll it into a ball, wrap in waxed paper and chill it for 2 hours.

Rhubarb stage
1 bunch rhubarb (500g), trimmed, cut up
2/3 cup sugar
3 tablespoons water

Cook the rhubarb mix over medium heat until it’s all softened, and drain off the runny syrup.

Pumpkin mix
4 cups pureed cooked pumpkin
1 teaspoon ground cinnamon
1 cm fresh ginger, finely chopped
2 well beaten eggs

Mix the pumpkin ingredients, and add to the cooked rhubarb.

Pie stage
Grease the pie dishes and crumble in the crust mix, spreading it to an approximately even layer. Add the filling.

Cook at 330°C for 8 minutes, then reduce to 160°C and cook for about 40 minutes, until a skewer comes out clean.

Lime Mousse Ice Cream

By popular demand, as an accompaniment, here’s how to make lime mousse ice cream, based on a mousse recipe from The Silver Palate Cookbook, with measurements translated to metric. I also reduced the fat content and slightly adjusted the technique to allow for the fact that freezing holds it solid.

50g unsalted butter
5 eggs
1 cup sugar
3/4 cup fresh lime juice (4-7 limes depending on size)
grated zest of 4-5 limes (depending on size)
300ml cream

Melt the butter in a double boiler. Beat the eggs and sugar, and add to the molten butter. Continue whipping the mix over medium heat until it turns to a custard (about 8 minutes), i.e., starts to thicken. Do not overcook, otherwise you'll get sugary scrambled eggs.

Remove from heat and add the lime ingredients. Cool to room temperature.

Whip the cream to the point where it switches from light and foamy to thick, and fold into the custard mix, taking care not to flatten the aeration out.

Chill well, then freeze in an ice cream maker (not absolutely critical: it will not set very hard with this much fat content).