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
Tag Archives: Agriculture
4 April 2016, Science Daily, Water cycle instability is here to stay posing major political and economic risks. Adaptation to new risks: A vital necessity for development policies. The current instability and unpredictability of the world water cycle is here to stay, making society’s adaptation to new risks a vital necessity when formulating development policies, a UN water expert warns. Robert Sandford, the EPCOR Chair for Water and Climate Security at the United Nations University’s Canadian-based Institute for Water, Environment and Health (UNU-INWEH), says long-term water cycle stability “won’t return in the lifetime of anyone alive today.” “What we haven’t understood until now is the extent to which the fundamental stability of our political structures and global economy are predicated on relative stability and predictability of the water cycle — that is, how much water becomes available in what part of the year. As a result of these new water-climate patterns, political stability and the stability of economies in most regions of the world are now at risk.” Ontario Lieutenant-Governor Elizabeth Dowdeswell, a former Executive Director of the UN Environment Programme, and UN Under Secretary-General David Malone, Rector of UN University, are among several expert speakers joining Sandford in Ottawa Tuesday April 5 at UNU-INWEH’s day-long 20th anniversary public seminar, “Water: The Nexus of Sustainable Development and Climate Change.” The seminar will focus on national policy changes needed worldwide to achieve global water security — a pre-requisite for reaching the new global Sustainable Development Goals, or SDGs, agreed upon by world leaders in September 2015. Read More here
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
24 March 2016, Climate News Network, Humans tilt climate books out of balance. Greenhouse gases from cattle, fertilisers, manure and agriculture mean that human activities have turned the land and soil into part of the global warming machine. In the great book-keeping of climate change, scientists have just discovered a big mistake. They have been wrong, they now think, to count on the mountains, the plains, the forests and the grasslands as an agency that slows climate change by absorbing carbon dioxide. It does absorb carbon dioxide. But the chilling news is that the soil itself may be making the world warmer. That is because humans have changed the way the landscape and its living things works, and now – thanks to those other greenhouse gases, methane and nitrous oxides, from cattle, fertilisers, manure and agriculture – the terrestrial biosphere is actually accelerating climate change. Twenty-three scientists from 16 laboratories and institutions report in Nature journal that they re-examined the sums on which climate forecasts depend. They concluded: “We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010.” Read More here