Notoriouosly unpredictable, the climate in this driest of continents plays a large part in the dominance of fatalism over the national culture. So it’s news when climate researchers release a report claiming the origins of the long-running drought in South East Australia are even more complex than previously thought. Until now it has been held that the main driver of the weather cycle in this region is ENSO – the El Nino Southern Oscillation – a fickle two to eight year repeating pattern of temperature anomolies in the Pacific Ocean.
Now though it seems that Indian Ocean variability is more significant. Previously it was thought the Indian Ocean Dipole (IOD) only affected Western and Southern Australia, but the evidence now presented indicates the IOD is a major contributor to the weather in South Eastern Australia as well. This suggestion goes some way towards explaining why the ‘Big Dry’ which began in 1996 was not broken by La Nina conditions in 2007, but continues to the present. Further, the evidence suggests that there have been an unprecedented three successive positive cycles in the past three years, bringing warm, dry winds, low rainfall and high temperatures to South Eastern Australia.
This is a new piece of information. According to a news report by Ben Cubby it ‘could overturn decades of weather research’. So it’s putting it mildly to say that this requires some interpretation. What then can we say about it? Is it good or bad? Who will benefit from this new reality (if such it is) and who stands to lose out? If this counts as knowledge, what is its power? Who and what does it change? The newspaper report of the announcement gives a number of clues.
For the lead author, Dr Caroline Ummenhofer, the news is positive since it might reduce uncertainty for farmers: “There really is that opportunity to improve seasonal forecasting and seasonal predictions due to these findings, because the Indian Ocean dipole is predictable several months in advance.”
For Professor Matthew England the co-director of the Climate Change Research Centre, the news is very negative, especially in terms of climate change trends: “If these Indian Ocean dipole events do follow the trend [of more positive and fewer negative events], this is a terrible piece of information for the Murray-Darling Basin.”
Meanwhile the authorities have the situation regulated by motitoring it carefully: ‘The Murray-Darling Basin Authority’s quarterly update yesterday showed the drought there is worsening. Toxic algae blooms are expected, water storage is down by two-thirds and decent rain is months away.’
In the article you are now reading, the phrases in bold print, all except one lifted from the news report, summarise the four cultures of Grid-group Cultural theory. The theory suggests that when faced with new information, we rush to make sense of it, to fill the interpretive vacuum – but typically we do so in one of four competing ways, and we organise our environment to reinforce one or another of these ‘cultural biases’ . In the case of Australian climate science, we can see this happening in real time. Is it just an effect of journalism – to try to cover all perspectives (but then this begs the question of what counts as ‘all’)?
Why not check it out for yourself, by observing how people construct their arguments and their worldviews?
The report is to be published in Geophysical Research Letters but here is the pre-print.