3 November 2015, The Conversation, As drought looms, the Murray-Darling is in much healthier shape – just don’t get complacent. Melbourne Cup Day is a significant day in the history of water policy in Australia. The first Tuesday in November 2006 saw the then Prime Minister John Howard intervene decisively in the growing drought crisis in the southern Murray-Darling Basin (MDB). Nine years on, the spectre of drought is back. The Murray Darling Basin Authority’s weekly reports show inflows into the River Murray (which can be seen as a proxy for the southern MDB) during the year to end September 2015 were the among the lowest on record. And the Bureau of Meteorology’s National Climate and Water Briefing last week suggests a warm and dry summer in prospect in the southern MDB, amid a still strengthening El Niño. Yet there are reasons to believe that these past nine years of stronger Commonwealth involvement have left the MDB much better placed to withstand an escalating drought. That said, there is no room for complacency, and continuing Commonwealth commitment is still needed if those hard-won gains are to be retained. Read More here
Tag Archives: Drought
29 October 2015, Yale Connections, Long-Term Drought Impacts on Trees. Scientists find that droughts harm trees for longer than previously understood. ANDEREGG: “We’ve known for decades that drought has harmful effects on trees. That during drought they grow slower and they have a higher chance of death.” That’s William Anderegg, a biologist at the University of Utah. He says until recently, researchers were not clear about what happened to the trees after a drought ended. So his team looked at the growth of trees after severe drought in more than a thousand forests across North America, Europe, and Asia. They found that even four years after a drought, trees continued to grow more slowly than normal. ANDEREGG: “Trees take up about a quarter of human emissions of CO2 each year, and that’s a very big slowing effect on climate change. So if droughts cause forests to take up less carbon, that could very much speed up the pace and the severity of climate change.” Anderegg says it is too early to know what the long-term implications will be. ANDEREGG: “Some of our best models suggest that forests could be relatively resilient and others suggest they could really die off en masse and lose a lot of their carbon to the atmosphere. And we don’t know which of those is more likely.” But Anderegg says that the future of the world’s forests is still in our hands. ANDEREGG: “I always like to emphasize that a lot of that future does depend on human decisions and what we do about climate change.” Read More here
28 August 2015, Climate News Network, Drought becoming the ‘new normal’ for Californians. Human impacts on global warming and water resources are threatening to turn the landscape of the US west into a dustbowl. One way or another, humans are to blame for the catastrophic drought in California that scientists say may be emerging as a “new normal”. Either humans have mismanaged the state’s water, or human-triggered global warming has begun to help turn America’s landscape of wine and roses into a dustbowl, according to two new studies. And the arguments have relevance extending far beyond the US west, as the European Drought Observatory has warned that much of mainland Europe is now caught up in the continent’s worst drought since 2003. The consequences of any drought could also be more enduring than expected. A research team in the US reports in the journal Ecological Applications that trees that survived severe drought in the US southeast 10 years ago are now dying – because of the long-ended drought. Read More here
30 July 2015, Science Daily, Drought’s lasting impact on forests. Forests across the planet take years to rebound from drought, storing far less carbon dioxide than widely assumed in climate models. In the virtual worlds of climate modeling, forests and other vegetation are assumed to bounce back quickly from extreme drought. But that assumption is far off the mark, according to a new study of drought impacts at forest sites worldwide. Living trees took an average of two to four years to recover and resume normal growth rates after droughts ended, researchers report today in the journal Science. “This really matters because in the future droughts are expected to increase in frequency and severity due to climate change,” says lead author William R.L. Anderegg, an assistant professor of biology at the University of Utah. “Some forests could be in a race to recover before the next drought strikes.” Forest trees play a big role in buffering the impact of human-induced climate change by removing massive amounts of carbon dioxide emissions from the atmosphere and incorporating the carbon into woody tissues. The finding that drought stress sets back tree growth for years suggests that Earth’s forests are capable of storing less carbon than climate models have calculated. Read More here