Category Archives: The Science

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5 February 2016, The Guardian, After climate cuts at CSIRO, who should we ask about global warming impacts on Australia? Netflix? Dr Penny Whetton had spent 25 years working on climate change modelling for Australia’s premier science agency, but in 2014 it was time to go. “I could see the writing on the wall,” says Whetton, who put up her hand to take a redundancy package in October 2014. This week, she has heard of the anger and sadness among her former CSIRO colleagues at the news that climate change research is being targeted for cutbacks and redundancies. Whetton still holds an Honorary Research Fellow position at the agency, where she had worked as a senior principal research scientist and one of the key people leading the CSIRO’s climate modelling work. She is one of a very small handful of Australian scientists to have been a lead author on three consecutive Intergovernmental Panel on Climate Change reports. Her central role has been to use climate models to work out the implications for climate change on Australia. Whetton had also been a leader of the project to deliver the latest climate change projections across Australia, released last year. In short, Whetton has intimate knowledge of what Australia’s climate modelling expertise is being used for. This week’s announcement by CSIRO executive director Larry Marshall has angered many in the country’s climate science community, who have been queuing up to criticise the moves. But beyond the implications of the announcement, there has also been much bemusement about Marshall’s statements and his apparent simplistic understanding of aspects of climate science. If Whetton saw the writing on the wall in October 2014 then surely everyone else should have been able to see the letters scrawled metres high when Marshall was appointed that same month. Read More here

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3 February 2016, Nature Communications, Evidence for the stability of the West Antarctic Ice Sheet divide for 1.4 million years. Past fluctuations of the West Antarctic Ice Sheet (WAIS) are of fundamental interest because of the possibility of WAIS collapse in the future and a consequent rise in global sea level. However, the configuration and stability of the ice sheet during past interglacial periods remains uncertain. Here we present geomorphological evidence and multiple cosmogenic nuclide data from the southern Ellsworth Mountains to suggest that the divide of the WAIS has fluctuated only modestly in location and thickness for at least the last 1.4 million years. Fluctuations during glacial–interglacial cycles appear superimposed on a long-term trajectory of ice-surface lowering relative to the mountains. This implies that as a minimum, a regional ice sheet centred on the Ellsworth-Whitmore uplands may have survived Pleistocene warm periods. If so, it constrains the WAIS contribution to global sea level rise during interglacials to about 3.3 m above present. Read More here

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28 January 2016, Climate Home, Scientists pour cold water on ocean geoengineering idea. One keenly-argued possible way of moderating the build-up of carbon dioxide in the atmosphere may not work, scientists have concluded. They say there is evidence that seeding the oceans with iron so that the algae that live there will multiply and devour more CO2 − thus preventing it reaching the atmosphere and intensifying the human contribution to global warming – is not as promising a solution as its supporters hope. The extra iron can certainly stimulate the algae to grow more vigorously, but at a cost. More algae in one part of the oceans may mean there will be fewer in other areas, the researchers say. Report: Scientists warn against geoengineering as short-term climate fix. They report in Nature journal that the depths of the central Pacific Ocean contain ancient sediments that cast doubt on iron’s ability to slow the Earth’s steady temperature rise. In parts of the oceans that lack the iron that plants need, algae are scarce. Experiments have shown that dumping iron into these areas can encourage algal growth, so large-scale fertilisation could theoretically reduce atmospheric CO2. The seafloor sediments the team studied show that, during past ice ages, more iron-rich dust blew from cold and barren landmasses into the oceans, apparently producing more algae in these areas and, presumably, a creating natural cooling effect. But the researchers say increased algal growth in one area can inhibit growth elsewhere, because ocean waters are always on the move and algae also need other nutrients, such as nitrates and phosphates. Read More here

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25 January 2016, The Guardian. Sea level rise from ocean warming underestimated, scientists say. Thermal expansion of the oceans as they warm is likely to be twice as large as previously thought, according to German researchers. The amount of sea level rise that comes from the oceans warming and expanding has been underestimated, and could be about twice as much as previously calculated, German researchers have said. The findings in the Proceedings of the National Academy of Sciences, a peer-reviewed US journal, suggest that increasingly severe storm surges could be anticipated as a result. Sea level can mount due to two factors – melting ice and the thermal expansion of water as it warms. Until now, researchers have believed the oceans rose between 0.7 to 1mm per year due to thermal expansion. But a fresh look at the latest satellite data from 2002 to 2014 shows the seas are expanding about 1.4mm a year, said the study. “To date, we have underestimated how much the heat-related expansion of the water mass in the oceans contributes to a global rise in sea level,” said co-author Jurgen Kusche, a professor at the University of Bonn. The overall sea level rise rate is about 2.74mm per year, combining both thermal expansion and melting ice. Read More here