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: Impacts Observed & Projected
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
4 September 2015, Climate News Network, Global tree census highlights need to restore forests. Mapping the density of forests reveals that there are far more trees on the planet than previously thought – but humans are destroying 15 billion a year. An international collaboration of scientists has just completed the ultimate green census – by calculating that the planet is home to 3.04 trillion trees. The latest estimate is far higher and almost certainly more accurate than any previous attempt. But the bad news is that humans are removing trees at the rate of 15 billion a year – and there are now about half as many as there were at the dawn of civilisation. For every person on Earth, there are 422 trees – in total, more than 3,000 billion deciduous or evergreen growths with woody trunks greater than 10 centimetres at breast height. The researchers based their study on close analysis of satellite imagery, and of data from 429,775 plots of trees as measured on the ground in 50 countries on every continent except Antarctica. Statistical techniques. They counted forests in 14 “biomes” − or different kinds of climate, soil and topography − and in places not normally associated with trees, such as deserts, savannah, swamps, tundra and high mountains. They then they used statistical techniques that could extend their sample density measurements to the whole terrestrial world. The scientists report in Nature journal that the tropical and subtropical forests are home to 1.39 trillion trees, while the boreal forests of the north contain 0.74 trillion, and the temperate zones hold 0.61 trillion. Read More here
2 September 2015, Washington Post, Wildfires have now burned a massive 8 million acres across the U.S. As of Tuesday, according to the National Interagency Fire Center, more than 8 million acres have burned in U.S. wildfires in 2015. 8,202,557 of them, to be precise. That’s an area larger than the state of Maryland. And the numbers are still growing: 65 large fires are currently raging across the country, particularly in California, Oregon, Washington, Idaho and Montana. That includes three Washington state fires or fire complexes that are larger than 100,000 acres burned. As of this writing, the United States remains at wildfire preparedness level 5 — the highest level — where it has been since Aug. 13. There are only six other years that have seen more than 8 million acres burned — 2012, 2011, 2007, 2006, 2005, and 2004 — based on National Interagency Fire Center records that date back to 1960. It is hard not to notice that all of these years came since the year 2000. Read More here