Sunday, 19 April 2009

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.