23 May 2017, The Conversation, Australian farmers are adapting to climate change. 2016-17 has been a great year for Australian farmers, with record production, exports and profits. These records have been driven largely by good weather, in particular a wet winter in 2016, which led to exceptional yields for major crops. Unfortunately, these good conditions go very much against the long-term trend. Recent CSIRO modelling suggests that changes in climate have reduced potential Australian wheat yields by around 27% since 1990. While rising temperatures have caused global wheat yields to drop by around 5.5% between 1980 and 2008, the effects in Australia have been larger, as a result of major changes in rain patterns. Declines in winter rainfall in southern Australia have particularly hit major broadacre crops (like wheat, barley and canola) in the key southeastern and southwestern cropping zones. There is strong evidence that these changes are at least partly due to climate change. Climate change is affecting farm productivity A recent study by the Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES) confirms that changes in climate have had a negative effect on the productivity of cropping farms, particularly in southwestern Australia and southeastern Australia. In general, the drier inland parts of the cropping zone have been more heavily affected, partly because these areas are more sensitive to rainfall decline. Smaller effects have occurred in the wetter zones closer to the coast. Here less rain can have little effect on – and can even improve – crop productivity. Farmers are reacting However, it’s not all bad news. The study finds that Australian farmers are making great strides in adapting to climate change. Much has been written about the fact that farm productivity in Australia has essentially flatlined since the 1990s, after several decades of consistent growth. The ABARES research suggests that changes in climate go some way towards explaining this slowdown. After controlling for climate, there has been relatively strong productivity growth on cropping farms over the past decade. However, while farms have been improving, these gains have been offset by deteriorating conditions. The net result has been stagnant productivity. Read More here
Tag Archives: Drought
23 February 2017, The Conversation, Australia’s 2016 environment scorecard: rains return but in some cases too late. After several dry years, vegetation across much of Australia received much-needed rains in 2016. But this broad pattern of improvement belies some major environmental damage in parts of the country – particularly in Tasmania, which was scorched by bushfire, the Gulf Coast and Cape York, which missed out on the rains’ return, and on the Great Barrier Reef, which suffered massive coral bleaching. That is the conclusion of our report on Australia’s Environment in 2016, released today. It’s a summary of the state of the nation’s environmental indicators, which we compiled by analysing huge amounts of satellite imagery, ground data, and water and landscape modelling. The report and the accompanying Australia’s Environment Explorer website summarise those data into graphs and plots for 13 environmental indicators. With most data extending back to at least the year 2000, this makes it possible to see how the environment is changing. Read More here
14 February 2017, Think Progress, Sinking from drought, California is now also flooding. After weeks of rain, Northern California’s surface water systems have been pushed to the breaking point, even while the effects of a five-year drought continue to threaten the state’s long-term groundwater supplies. More than 180,000 people were evacuated Sunday afternoon after spillways for the Oroville Dam in Northern California showed signs of possible collapse. The potential flooding comes as California begins to emerge from its historic, drought. But despite the overabundance of water on the surface, drought conditions underground have likely had a permanent impact on the state. Even under the best conditions, it could take half a century for underground reservoirs to refill. Recent analysis from the California Institute of Technology shows that drought — combined with water use — has caused parts of California to sink, perhaps permanently. Some places show up to two feet of subsidence over the past two years. That’s because as surface water from rain and snowmelt has decreased, farmers have been using more groundwater from reservoirs. “Subsidence caused by groundwater pumping in the Central Valley has been a problem for decades,” write the authors of a new study, which uses NASA data to track California’s sinking. Pumping groundwater reduces the support below-ground aquifers give to the surface, causing it to sink. In recent years, that process has been sped up, as California’s drought has reduced the surface water available to farmers. While surface water can come in the form of rain, or snowmelt, groundwater sits in aquifers and is the result of a slow build up of water below ground. Read More here
16 December 2016, The Conversation, Climate change played a role in Australia’s hottest October and Tasmania’s big dry in 2015. Climate change made some of Australia’s 2015 extreme weather events more likely, according to research published today in the Bulletin of the American Meteorological Society. As part of an annual review of global weather extremes, these studies focused on October 2015, which was the hottest on record for that month across Australia. It was also the hottest by the biggest margin for any month. October 2015 was also the driest for that month on record in Tasmania, which contributed to the state’s dry spring and summer, and its bad fire season. El Niño events usually drive global temperatures higher, and 2015 had one of the strongest on record. So were these records due to El Niño, or climate change? The research shows that while El Niño had some influence on Australia’s weather, it was not the only culprit. El Niño packed a punch – or did it? In 2015, a strong El Niño developed, with record high temperatures in the central equatorial Pacific Ocean contributing to 2015 being the hottest year on record globally (although 2016 will smash it). The Indian Ocean was also very warm. El Niño is often associated with warm and dry conditions across eastern Australia, particularly in spring and summer. The new studies found that for Australia as a whole, while El Niño did make the continent warmer, its direct contribution to record temperatures was small. Only in the Murray Darling Basin did El Niño make it more likely that the October 2015 heat would be a record. El Niño also played a small but notable role in the dry October in Tasmania. Read More here