18 May 2016, The Conversation, Are toxic algal blooms the new normal for Australia’s major rivers? For much of this year, up to 1,700 kilometres of the Murray River has been hit by a serious outbreak of potentially toxic blue-green algae, which has flourished in the hotter-than-average conditions. After three months, the river is now recovering with the arrival of wet weather. But we are unlikely to have seen the last of these poisonous microbes. Large blue-green algal blooms are a relatively new phenomenon in inland waterways. In 1991 an algal bloom affected more than 1,000 km of the Darling River, the first time such an event had been reported in an Australian river, and one of the few times internationally. It was an environmental disaster, killing livestock and striking a telling blow against Australia’s reputation as a clean, green farming nation. The response was decisive: a state of emergency was declared, and the bloom ultimately gave rise to significant investment by state and federal governments into freshwater research, particularly in the Murray-Darling Basin. Why no emergency now? Fast forward two and a half decades to the latest bloom afflicting the Murray River, one of Australia’s most socially, economically and culturally significant waterways. The past decade has seen four similar blooms on the Murray River: in 2007, 2009, 2010 and now. Yes, they have garnered press attention, but there has not been the same call to arms that we saw when the Darling River was struck in 1991. It is almost as if such significant environmental events are now simply seen as the new normal. Why the apparent complacency? The 2007, 2009 and 2010 algal blooms on the Murray River all happened during the Millennium Drought, and hence were probably ascribed to an aberration in the weather. In reality, the situation may have more to do with how we manage water in Australia – particularly during periods of scarcity, such as the one we may well be entering now. Read More here
Category Archives: Food & Water Issues
28 March 2016, Climate News Network, Plants’ heat response means fiercer heatwaves. Asia faces more extreme heat by mid-century as some plant species react unexpectedly to rising average temperatures, new research shows. Tomorrow’s heat waves could be even hotter than climate scientists have so far predicted. Maximum temperatures across the Asian continent from Europe to China could be 3°C to 5°C higher than previous estimates – because the forests and grasslands will respond in a different way. Australian scientists report in the journal Scientific Reports that they looked at the forecasts made by the Intergovernmental Panel on Climate Change under the notorious “business-as-usual” scenario, in which the world’s nations go on burning ever more fossil fuels, to release ever more greenhouse gases. The average global temperatures will rise steadily – but this rise will be accompanied by ever greater and more frequent extremes of heat. But then Jatin Kala of Murdoch University in Perth, Western Australia, and colleagues factored in the responses of the plants to rising temperatures.They looked at data from 314 species of plant from 54 research field sites. In particular, they investigated stomatas, tiny pores on the leaves through which plants absorb carbon dioxide and shed water to the atmosphere. Response crucial What matters is how vegetation responds to extremes of heat. Researchers have already established that plants respond, not always helpfully: extremes can alter the atmospheric chemistry unfavourably for plants, and certainly reduce crop yields. But other scientists have confirmed the so-called carbon dioxide fertilisation effect: as more carbon becomes available, plants use water more economically and so even though drylands may get drier the landscape can also get greener, and growth tends to begin ever earlier as winters get warmer, and spring arrives earlier. Read more here
10 March 2016, The Conversation, Global food production threatens to overwhelm efforts to combat climate change. Each year our terrestrial biosphere absorbs about a quarter of all the carbon dioxide emissions that humans produce. This a very good thing; it helps to moderate the warming produced by human activities such as burning fossil fuels and cutting down forests. But in a paper published in Nature today, we show that emissions from other human activities, particularly food production, are overwhelming this cooling effect. This is a worrying trend, at a time when CO₂ emissions from fossil fuels are slowing down, and is clearly not consistent with efforts to stabilise global warming well below 2℃ as agreed at the Paris climate conference. To explain why, we need to look at two other greenhouse gases: methane and nitrous oxide. The other greenhouse gases Each year, people produce about 40 billion tones of CO₂ emissions, largely from burning fossil fuels and deforestation. This has produced about 82% of the growth in warming due to greenhouses gases over the past decade. The planet, through plant growth, removes about a quarter of this each year (another quarter goes into the oceans and the rest stays in the atmosphere and heats the planet). If it didn’t, the world would warm much faster. If we had to remove this CO₂ ourselves, it would cost hundreds of billions of dollars each year, so we should be very grateful that the Earth does it for free. Apart from CO₂, there are two other main greenhouse gases that contribute to global warming, methane (CH₄) and nitrous oxide (N₂O). In fact, they are both more potent greenhouse gases than CO₂. The global warming potential of methane and nitrous oxide is 28 and 265 times greater than that of CO₂, respectively. The human emissions of these gases are largely associated with food production. Methane is produced by ruminants (livestock), rice cultivation, landfills and manure, among others. Read More here
10 March 2016, Science Daily, Cutting cattle carbon: Bad breath and flatulence. Cattle have bad breath and commonly suffer from severe, chronic flatus generating large amounts of methane, which is a greenhouse gas and a driver of anthropogenic global warming. There is an obvious answer to this problem, stop breeding cattle. Unfortunately a large proportion of us enjoy our bovine dairy products and meat too much. Until synthetic products that are indistinguishable from the real thing become available and accepted by milk drinkers and steak fans, we will have to look into alternative approaches to reducing the carbon emissions from these creatures. Writing in International Journal of Global Warming, Abdelmajid Moumen, Ghizlane Azizi, Kaoutar Ben Chekroun and Mourad Baghour of the Université Mohamed 1er, in Nador, Morocco, have reviewed the various approaches to reducing methane emissions from cattle and other livestock. These approaches involve improved genetic selection through breeding, modification of dietary composition, or through rumen microbial manipulation, vaccines against the methanogenic bacteria that generate the methane in these animals and various other techniques. It is possible that among the approaches or with a combination of approaches there might be a way to reduce the global burden of methane emissions from livestock. Read More here