Preceding sections outlined why we need to recognise the climate’s materialities and agency. This section proposes that we must recognise the cultural construction of climate normal and climate change. In addition to being a geophysical phenomenon, climate change is also deeply cultural, in the sense that both climate change and ‘climate normal’ are culturally constructed. Hulme et al. ^[2] argued that the whole framing of climate change implies a reference to ‘climate normal’, itself constructed via a cooperative global scientific effort. This effort involves the measurements and statistical manipulations used to derive the averages that define ‘normal’ climatic conditions. The notions of the ‘climate’ embeds these expectations of normality, and therefore, of change from the normal conditions ^[2]

When we apply the expectation of a standard or predictable climate, the deviations from normal conditions are referred to as extreme events and ‘anomalies’, implying the abnormality of non-average conditions (see Figure 1Figure 2). However, in southern Australia, conditions conforming to the “average” conditions occur coincidentally due to fundamental drivers of the oceans’ climatic conditions that bring oscillating wet–dry cycles ^[8][9]. Reconstructions of the hydro-climate beyond the instrumental records, using climate proxies, demonstrate that recurrent droughts, punctuated by floods, typify the climate patterns over centuries and millennia ^[10]. Furthermore, these proxy records indicate that extreme flood events and long periods of drought are distinct and typical parts of the historical record ^[10].

Policy ‘artefacts’—posters, brochures, websites and reports intended to inform, educate and instruct ‘the public’—offer potential sources for research exploring the cultural construction of climate and how official documents represent climatic conditions ^[11][12]. For example, the MDBA’s ^[13][14] (2011a and 2011b) posters on river inflows (Figure 1Figure 2) and the Millennium Drought’s rainfall anomalies (Figure 2Figure 3) reveal ways the cultural construction of ‘climate normal’ are reinforced and refracted by countless representations of nature ^[3]. With their references to averages and deviations from them, these posters offer evidence that averages conditions are abnormal due to the climate oscillating through extended cycles of drought–flood ^[8][9][10]. These representations of the climate demonstrate how concepts of ‘climate normal’ are reinforced through posters and other information sources and used to justify policies that attempt to drought-proof irrigated agriculture in the basin ^[15][11].

The two posters reproduced above are examples of the abundance of information that conditions our comprehension of the climate. These representations embed concepts of nature and its averaged conditions ^[3], and that define variations or changes arising in contrast to these averages. Averages are not just used to represent the climate, but are also the basis of water resource planning in the MDB, where averages of available water resources were projected forward to 2030 by the statutory instrument of the Basin Plan, despite strong scientific evidence of a drying climate ^[16][17][18].

The Millennium Drought (1996–2010) had severe impacts on riverine ecosystems, industries and communities throughout the Basin ^[8]. The drought was defined as a national crisis that triggered major reforms ^[8]. However, while there is much evidence for climate change contributing to the drying of the MDB, the MDBA relied on the 114-year climate history (1895–2009) for the Basin Plan modelling ^[16]. Therefore, the MDB Plan relies on the historical climate during the instrumental period, as the basis for future projections. This failure to adequately incorporate climate science into responses to climate risks has been described by a formal judicial inquiry as incomprehensible maladministration ^[17]. However, this choice may also indicate a deep-seated yearning from settler–colonial water governance institutions for a safe, reliable, ‘normal’ climate, one that delivers predictable water supplies to the intensively irrigated agriculture that has arisen in the Basin in a little over a century of re-engineering the rivers for that purpose.

In contrast to irrigated agriculture, the ecosystems of the MDB have evolved to be superbly adapted to the boom–bust, flood–drought cycles driven by the southern continent’s highly variable climate ^[8][9] (see also FigureFigure 2 1 and Figure 2Figure 3). However, these ecosystems cannot adjust to the impacts of over extraction of water for irrigation ^[19][20]. A deep reluctance to accept the flood–drought cycle is apparent in the history of Australia’s policies ^[21][22], many of which focused on drought proofing—ambitious engineering schemes intended to overcome the continent’s variability ^[15][11][23]. A similar type of reluctance to accept the reality of climate change is driving maladaptive policy formulation, including an unattainable search for scientific certainty, and the conflation of climate variability with climate change in many official documents ^[17].

By bringing a cultural perspective to interpreting the MDB reforms, this paper argues that the hydro-climatic conditions of the Basin are coproduced by culture. These variable conditions are a combination of the natural or physical phenomena, and the way water and rivers are defined, understood and governed. Settler–colonial Australia has increasingly defined water as an extractable resource that can be exchanged in a market economy, to the detriment of a range of other aspects of the value of rivers ^[19][24]. To protect these other aspects of value and to become genuinely inclusive of Indigenous People’s perspectives and relationships will require significant renegotiations on the fundamentals principles and practices of how water is understood and governed in modern Australia ^{[24][25][26][27]}. Developing models of co-governance and recognising Indigenous wisdom, experience and connections provides important opportunities for recalibrating the nation’s relationships to its rivers ^[25][26][27]. As a nation, Australia can only do this through integrating natural and cultural heritage conservation, developing appropriate models of economic development and recognising the long and proud history of Indigenous governance of rivers and their catchments ^[26][27]. Incorporating long-term cultural perspectives provides significant opportunities for treating rivers, and their peoples, with greater respect and reverence ^[26][27].

Figure 12. River inflows for the Murray Darling Basin ^[13].

Figure 23. Rainfall “anomalies” 2002 to 2011 in the MDB ^[14].