30 March 2016, Board on Atmospheric Sciences and Climate, Attribution of Extreme Weather Events in the Context of Climate Change (report). The science of extreme event attribution has advanced rapidly in recent years, giving new insight to the ways that human-caused climate change can influence the magnitude or frequency of some extreme weather events. Confidence is strongest in attributing types of extreme events that are influenced by climate change through a well-understood physical mechanism—for example, the more frequent heat waves that are closely connected to human-caused global temperature increases. Confidence is lower for other types of events, such as hurricanes, whose relationship to climate change is more complex and less understood at present. For any extreme event, the results of attribution studies hinge on how questions about the event’s causes are posed, and on the data, modeling approaches, and statistical tools chosen for the analysis. Read More here
Tag Archives: Extreme Events
28 March 2016, Climate News Network, Plants’ heat response means fiercer heatwaves. Asia faces more extreme heat by mid-century as some plant species react unexpectedly to rising average temperatures, new research shows. Tomorrow’s heat waves could be even hotter than climate scientists have so far predicted. Maximum temperatures across the Asian continent from Europe to China could be 3°C to 5°C higher than previous estimates – because the forests and grasslands will respond in a different way. Australian scientists report in the journal Scientific Reports that they looked at the forecasts made by the Intergovernmental Panel on Climate Change under the notorious “business-as-usual” scenario, in which the world’s nations go on burning ever more fossil fuels, to release ever more greenhouse gases. The average global temperatures will rise steadily – but this rise will be accompanied by ever greater and more frequent extremes of heat. But then Jatin Kala of Murdoch University in Perth, Western Australia, and colleagues factored in the responses of the plants to rising temperatures.They looked at data from 314 species of plant from 54 research field sites. In particular, they investigated stomatas, tiny pores on the leaves through which plants absorb carbon dioxide and shed water to the atmosphere. Response crucial What matters is how vegetation responds to extremes of heat. Researchers have already established that plants respond, not always helpfully: extremes can alter the atmospheric chemistry unfavourably for plants, and certainly reduce crop yields. But other scientists have confirmed the so-called carbon dioxide fertilisation effect: as more carbon becomes available, plants use water more economically and so even though drylands may get drier the landscape can also get greener, and growth tends to begin ever earlier as winters get warmer, and spring arrives earlier. Read more here
25 March 2016, Climate News Network, Past emissions cause mounting climate havoc. Despite signs that the world will cut its future fossil fuel use, greenhouse gases already emitted are still driving accelerating climate change.Climate change has reached the point where it may outstrip the quickening efforts to slow it by reducing emissions of carbon dioxide and other greenhouse gases, scientists say. They say humans are now releasing CO2 into the atmosphere 10 times faster than natural processes have ever done in the last 66 million years, before the extinction of the dinosaurs. The disclosure comes in the World Meteorological Organisation’s State of the Climate report, published in the journal Nature Geoscience. The lead author, Professor Richard Zeebe of the University of Hawaii, said: “Our carbon release rate is unprecedented over such a long time period [and] means that we have effectively entered a ‘no-analogue’ state. “The present and future rate of climate change and ocean acidification is too fast for many species to adapt, which is likely to result in widespread future extinctions.” “The window of opportunity for limiting global temperature rise to well below 2°C . . . is narrow and rapidly shrinking. The effects of a warming planet will be felt by all” The UN secretary-general, Ban Ki-moon, said: “Climate change is accelerating at an alarming rate. The window of opportunity for limiting global temperature rise to well below 2°C – the threshold agreed by world governments in Paris in December last year – is narrow and rapidly shrinking. The effects of a warming planet will be felt by all.” The WMO secretary-general, Petteri Taalas, said the present “alarming” rate of climate change as a result of greenhouse gas emissions was “unprecedented in modern records”. “The future is now”, he said. Yet less than a week ago the International Energy Agency announced that global energy-related emissions of carbon dioxide had shown no increase for the second year in a row. The announcement was widely hailed as significant good news, with the IEA’s executive director, Fatih Birol, describing it as “yet another boost to the global fight against climate change”.Read More here
24 March 2016, EurekAlert, Insurance for an uncertain climate. In December, negotiators at the Paris climate meeting adopted insurance as an instrument to aid climate adaptation. Earlier in the year, the leaders of the G7 pledged to bring climate insurance to 400 million uninsured individuals in poor countries by 2020. In a new article in the journal Nature Climate Change, experts from the London School of Economics and Political Science, Deltares and International Institute for Applied Systems Analysis welcome these developments, but also lay out the difficulties that policymakers will face in turning the ideas into action. They warn that ill-designed and poorly implemented insurance instruments could fail to reach the goals of negotiators, or worse, prove detrimental to the very people they are intended to protect. Swenja Surminski, Senior Research Fellow the Grantham Research Institute on Climate Change and the Environment at the London School of Economics and Political Science led the article. She says, “Poor communities are much more impacted by extreme weather such as floods, droughts, and heatwaves. Rather than ad-hoc and unpredictable payments after these events, insurance approaches can be set up in advance of these impacts, and be more efficient and provide better support to these vulnerable people.” Bayer was one of the first to propose insurance as a mechanism to reimburse people for the impacts of climate change, and to examine the potential benefits and trade-offs of such policies. She says, “With the new momentum we have for these policies, we now have the opportunity to put the right insurance systems in place.” While insurance could provide funding to help people in need, the researchers point out several ways that such mechanisms could fail: Read More here