22 October 2015, Climate News Network, Hurricanes’ economic havoc as world warms. Analysis of insurance data convinces environmental economists that climate change is pushing up the cost of dealing with the disastrous effects of extreme weather events. Climate change could already be costing the US billions of dollars each year in hurricane damage alone. Economists from Mexico and Europe believe that somewhere between $2bn and $14bn of the financial costs of hurricane damage in 2005 could be attributed to the impact of global warming. This is a bold statement. But Francisco Estrada, an environmental economics researcher at the National Autonomous University of Mexico, and European colleagues report in Nature Geoscience that they have looked at the pattern of economic losses from hurricanes that matches a rise between 1990 and 2005 in the number and intensity of tropical cyclones. They say that this upward trend in loss “cannot be explained by commonly-used socioeconomic variables”. The distinction is an important one. Economic damage from climate-related events − ice storms, drought, flood, windstorms and heatwaves – has been on the increase for decades, but one explanation for this is population growth and economic development, even in the poorest regions. Read more here
Category Archives: Impacts Observed & Projected
18 October 2015, Climate News Network, Climate changes can kick in below 2°C limit. Sudden shifts in settled climates can occur long before global warming reaches the internationally-agreed safety level, European scientists say. Climate change could arrive with startling speed. New research has identified at least 37 “tipping points” that would serve as evidence that climate change has happened – and happened abruptly in one particular region. And 18 of them could happen even before the world warms by an average of 2°C, the proposed “safe limit” for global warming. Weather is what happens, climate is what people grow to expect from the weather. So climate change, driven by global warming as a consequence of rising carbon dioxide levels, in response to more than a century of fossil fuel combustion, could be – for many people – gradual, imperceptible and difficult to identify immediately. But Sybren Drijfhout, of the University of Southampton in the UK and his collaborators in France, the Netherlands and Germany, are not so sure. They report in the Proceedings of the National Academy of Sciences that they “screened” the massive ensemble of climate models that inform the most recent reports from the Intergovernmental Panel on Climate Change, and found evidence of abrupt regional changes in the ocean, the sea ice, the snow cover, the permafrost and in the terrestrial biosphere that could happen as average global temperatures reached a certain level. The models did not all simulate the same outcomes, but most of them did predict one or more abrupt regional shifts. No safe limit. But the future is not an exact science. “Our results show that the different state-of-the-art models agree that abrupt changes are likely, but that predicting when and where they will occur remains very difficult,” said Professor Drijfhout. “Also, our results show that no safe limit exists and that many abrupt shifts already occur for global warming levels much lower than two degrees.” The idea of a “tipping point” for climate change has been around for decades: the hypothesis is that a climate regime endures – perhaps with an increasing frequency of heat waves or windstorms or floods – as the average temperatures rise. However, at some point, there must be a dramatic shift to a new set of norms.Read More here
15 October 2015, The Conversation, Death of a landscape: why have thousands of trees dropped dead in New South Wales? Trees die – that’s a fact of life. But is the death of an entire iconic landscape of Eucalyptus in the Cooma-Monaro region of New South Wales natural? For over a decade, large stands of Eucalyptus viminalis, commonly known as Ribbon Gum or Manna Gum, have been gradually declining in health, and now stand like skeletons in huge tree graveyards. In our recently published survey we found the affected area to cover almost 2,000 square km, about the size of the area burnt in the devastating Ash Wednesday bushfires in Victoria or more than the area covered by the 2003 Canberra fires. Within this area, almost every Ribbon Gum is either dead or showing signs of severe stress and dieback, with thinning crowns full of dead branches. Other tree species seem to be surviving, but this smooth-barked gum with its characteristic ribbons of peeling park, once the dominant tree of the Monaro, now seems set to disappear from the landscape. Read More here
14 October 2015, Climate News Network, Antarctic ice shelf melting could double by 2050. Scientists find that the combination of global warming and powerful winds sweeping snow off the ice of Antarctica threatens to speed up sea level rise. Antarctica, the planet’s largest desert, is home to 90% of the world’s ice – enough to raise global sea levels by at least 60 metres. So what happens to its ice and snow is a matter of serious concern to all of us. One group has just predicted that, by 2050, the rate at which the ice shelves melt will double. Another reports that powerful winds are not just shifting Antarctica’s snow, but are also blowing 80 billion tonnes of it away, into the sea or the atmosphere. Both cases exemplify the challenges of climate research and the construction of projections for the future. Inland glaciers Ice shelves are already afloat: if they melt, that will make no difference to sea levels. But floating ice that is fixed to the continental shelf also serves as a brake on the flow of glaciers further inland. So without the ice shelf “doorstops”, these could start to shed ice ever faster, and accelerate sea level rise. Luke Trusel, postdoctoral scholar at the Woods Hole Oceanographic Institutionin the US, and colleagues report in Nature Geoscience that they foresee a doubling of surface melting of the ice shelves by 2050. If greenhouse gas emissions from fossil fuel combustion continue at the present rate, by 2100 the melting may surpass the levels associated with collapse of the shelves. Read More here