14 September 2015, Climate News Network, Southern Ocean starts to soak up carbon again. Scientists report that the great oceanic “lung” is again breathing in vast amounts of carbon dioxide from the atmosphere – but can’t say why or whether it will last. The high seas have begun to respond again to the changes in the atmosphere, with two new studies confirming that the Southern Ocean is absorbing more atmospheric carbon. Levels of carbon dioxide in the atmosphere have been steadily increasing as humans burn ever more fossil fuels, but climate scientists will probably hesitate before exhaling sighs of relief over the latest findings. Rising CO2 in the atmosphere means global warming, which means climate change, melting ice caps, rising sea levels − and even more global warming and climate change. So the discovery that one great stretch of hostile ocean is soaking up more of the stuff sounds like very good news. However, the celebrations are likely to be cautious, as there is no guarantee that the process is permanent. Read More here
Category Archives: The Science
11 September 2015, The Conversation, Ignored by the government, shrunk by resignations – where now for Australia’s Climate Change Authority? Bernie Fraser’s resignation as chairman of Australia’s Climate Change Authority has left many wondering what is left of it and what its future might be. Established three years ago as part of the climate change package negotiated by the previous parliament’s Multi-Party Climate Change Committee, the Authority was formed to serve as the principal source of climate policy advice to the federal government, particularly on the issue of emissions targets. Championed by the then Greens deputy leader Christine Milne, it was modelled closely on Britain’s Committee on Climate Change. The Authority is legislated to have nine part-time members, including the Chief Scientist ex officio. When the Abbott government was elected two years ago it expressed its intention to abolish the Authority along with the rest of the Labor government’s climate policy architecture. Unlike the former Climate Commission, which had a public education role (and since losing government backing has morphed into the independent Climate Council), the Authority was established by legislation as a statutory authority. The government could not obtain sufficient support in the Senate to abolish the Authority. In particular, Palmer United Party leader Clive Palmer struck a deal with the government in which he would support thecarbon tax repeal but not the abolition of the Climate Change Authority. With the Authority saved, Palmer said he wanted the government to instruct it to assess whether Australia should have an emissions trading system at some time in the future, and what conditions should trigger its introduction, taking special note of the policies of Australia’s major trading partners. The government agreed to Palmer’s request to extend funding for the Authority. Continued funding was essential in order to sustain the Authority’s secretariat, based in Melbourne, which at its peak reached around 35 but now stands at around 25. On its formation the Authority attracted some of the best and brightest to work for it. Read More here
10 September 2015, The Conversation, Sure, winter felt chilly, but Australia is setting new heat records at 12 times the rate of cold ones. Spring feels like a welcome relief from an Australian winter that felt very cold and very long. Melbourne has just shivered through its coldest winter in 26 years and Canberra hibernated through more cold nights than any winter since 1997. But while it felt cold, it turns out we’ve just become accustomed to unusually warm conditions. My new study online in Geophysical Research Letters (with my colleague Andrew King) shows that Australia has been losing out on cold temperature records over the past 55 years. We investigated the frequency of new hot and cold temperature records for months, seasons and years, for each state and Australia as a whole, from 1910 to 2014. The results were straightforward. Record-breaking hot temperatures have outnumbered new cold records by a factor of 12 to 1 since the beginning of this century. The cause is also clear: global warming. Yet people’s ability to recognise climate extremes is easily affected by our perceptions. Riding my bike around frosty Canberra this winter felt brutally and unusually cold. But in reality it was only a bit colder than recent “warm” winters. Such misperceptions about climate extremes are common. During the record-breaking spring temperatures in Australia in 2013, Prime Minister Tony Abbott said: “…the thing is that at some point in the future, every record will be broken, but that doesn’t prove anything about climate change. It just proves that the longer the period of time, the more possibility of extreme events.” At first pass, this sounds like common sense. But statistically, it’s wrong. In an unchanging climate, new temperature records actually become less likely to occur with time, because each new record would be harder to beat in the absence of anything driving temperatures in a particular direction. Read More here
29 August 2015, Climate News Network, Climate models may misjudge soils’ carbon emissions. How soil organisms cope with decaying vegetation is much less certain than climate models suppose, researchers say, and carbon emission estimates may be wrong. Some of the microscopic creatures which live in the soil are able to digest dead plants and trees, turning their contents into gas and minerals. But researchers say their work show that our understanding of how organic material is decomposed is fundamentally wrong, calling into question some current climate models. The researchers, from Lund University, Sweden, and the University of New Hampshire, USA, have published their study in the journal Ecological Monographs. They say it means that climate models which include micro-organisms in their estimates of future climate change must be reconsidered. When plants or trees die, their leaves and branches fall to the ground and the organic matter which is absorbed by the soil is then decomposed, mainly by the activity of fungi and bacteria, which convert the dead materials into the main greenhouse gas, carbon dioxide, and mineral nutrients. Until now, the Lund team says, scientists had thought that high-quality organic materials, such as leaves that are rich in soluble sugars, were mainly decomposed by bacteria, leaving the lower-quality matter, like cellulose and lignin, to be broken down mainly by fungi. Expectations confounded. Previous research has suggested that organic material decomposed by fungi results in less CO2 and nutrient leakage compared with matter decomposed by bacteria. This is important for the climate models in use today, as any change in the loss of CO2 and mineral nitrogen would alter the soil’s contribution to greenhouse gases and eutrophication, the process in which the release of excessive chemical pollution causes algal blooms in watercourses. Read More here