Regime transitions of Australian climate and climate extremes

Systematic changes, since the beginning of the 20th century, in average and extreme Australian rainfall and temperatures indicate that Southern Australian climate has undergone regime transitions into a drier and warmer state. South-west Western Australia (SWWA) experienced the most dramatic drying trend with average streamflow into Perth dams, in the last decade, just 20 % of that before the 1960s and extreme, decile 10, rainfall reduced to near zero. In south-eastern Australia (SEA) systematic decreases in average and extreme cool season rainfall became evident in the late 1990s with a halving of the area experiencing average decile 10 rainfall in the early 21st century compared with that for the 20th century. The shift in annual surface temperatures over SWWA and SEA, and indeed for Australia as a whole, has occurred primarily over the last 20 years with the percentage area experiencing extreme maximum temperatures in decile 10 increasing to an average of more than 45 % since the start of the 21st century compared with less than 3 % for the 20th century mean. Average maximum temperatures have also increased by circa 1 °C for SWWA and SEA over the last 20 years. The climate changes are associated with atmospheric circulation shifts and are indicative of second order regime transitions, apart from extreme temperatures for which the dramatic increases are suggestive of first order transitions.

Leaf Removal Applied to a Sprawling Canopy to Regulate Fruit Ripening in Cabernet Sauvignon

Under the effects of climate change, it is becoming increasingly common to observe excessively fast grape sugar accumulation while phenolic and flavour development are lagging behind. The aim of this research was to quantify the impacts of three different leaf removal techniques on the canopy architecture and ripening of Cabernet Sauvignon trained in a sprawl trellis system. Treatments were performed at veraison (~14 °Brix) and included (i) control; (ii) leaf plucking in the bunch zone; (iii) leaf plucking the top two-thirds of shoots, apical to the bunches; and (iv) shoot trimming. On the date of harvest, no significant difference in total soluble solids was observed between treatments. Other results including the effect of the treatments on fruit acidity, anthocyanins, phenolics, and tannins were somewhat inconclusive. While various other studies have shown the potential of leaf removal to achieve slower grape sugar accumulation without affecting the concentration of anthocyanins, phenolics, and tannins, the results of this study do not indicate a decrease in the rate of grape sugar accumulation as a result of the investigated defoliation techniques. Given the cost of implementing these treatments, the results of this study do not support the use of these methods for the purpose of delaying fruit ripening in a hot Australian climate.

A rhetorical perspective on youth environmental activism

As “alternative” [Maeseele, 2009] science communicators, young people (of pre-voting age) have an important role to play in the climate communication arena. Youth have access to rhetorical resources associated with evidence-based and emotional appeals. However, they are challenged by political, media and public entities on their ability to effectively engage with politicised scientific issues. Their credibility and authority to speak on climate issues are challenged. This piece takes a rhetorical lens to a current youth climate change advocacy case study, the ‘School Strike for Climate’. I argue that Australian youth are criticised for being politically inexperienced in attempts to silence them from speaking out about Australian climate change policy. Implications for science communicators working in the climate change space, and the ‘Strike’ participants themselves are discussed.

Australian Climate Fiction

Climate is an important part of fictional scene setting, whether it be geographical—is the scene in the desert or in the tropics?—or seasonal—is it winter or is it summer? And this is perhaps especially true of Australian literature, where the majority of writers are still descendants of Anglo-Celtic settlers, living in more or less uneasy relationship with a distinctly non-Anglo-Celtic natural environment. Climate has thus been a characteristically Australian literary preoccupation: the titles of Vance Palmer’s Cyclone (1947), for example, or Patrick White’s Eye of the Storm (1973) speak for themselves. But “cli-fi” in the sense of the term coined by Dan Bloom in 2007 refers, not to climate per se, nor even to climate change per se, but much more specifically to fictions concerned with the effects of anthropogenic climate change, that is, to the literature of global warming. This is a much more recent preoccupation, which dates only from the late 1970s when the US National Research Council and the World Meteorological Organization first published predictions that then current levels of carbon dioxide (CO2) emissions would result in significant increases in average global temperatures. The short history of Australian “cli-fi” can be traced from the first publication of George Turner’s The Sea and Summer in 1987.