Extreme weather images in the media cause fear and disengagement with climate change

The paper ‘ Images of Extreme Weather: Symbolising Human Responses to Climate Change’, by Brigitte Nerlich & Rusi Jaspal, published in Science as Culture, reveals that extreme weather images represent human suffering and loss. They are iconic of climate change and are symbols of its natural impacts.Reporting on extreme weather has increased over the last few years. In the past social scientists, and media and communication analysts have studied how climate change is depicted in the text of media and social media. While researchers have become increasingly interested in climate change images, they have not yet studied them with respect to symbolising certain emotions.The International Panel on Climate Change (IPCC) published a draft report on extreme weather and climate change adaptation. The report was covered in the news and illustrated with images. Some of these depicted ‘extreme weather’, in particular with relation to floods, droughts and heat waves, hurricanes and ice/sea-level rise.Researchers studied images published in the news to illustrate their coverage of the IPCC report. They used visual thematic analysis, examining the way they might symbolise certain emotional responses, such as compassion, fear, guilt, vulnerability, helpless, courage or resilience.Results showed that images of flooding displays people in the developing world ‘getting on with it’. It portrays individuals accustomed to flooding and that they can overcome the extreme weather. The images showed cheerful behaviour of those who are affected by flooding; lack of victimhood; engagement in their day-to-day activities and communal aspects of coping with flooding.New research has shown that images of extreme weather in the media create negative emotional meanings and might lead to disengagement with the issue of climate change. The images symbolised fear, helplessness and vulnerability and, in some cases, guilt and compassion. …

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Global warming could change strength of El Niño

Sep. 11, 2013 — Global warming could impact the El Niño Southern Oscillation (ENSO), altering the cycles of El Niño and La Niña events that bring extreme drought and flooding to Australia and many other Pacific-rim countries.New research published in Nature Geoscience using coral samples from Kiribati has revealed how the ENSO cycle has changed over the past 4300 years. This research suggests that external changes have an impact on the strength and timing of El Niño events.”Our research has showed that while the development of La Niña and El Niño events is chaotic and hard to predict, the strength of these events can change over long time spans due to changes in the global climate,” said one of the paper’s authors Dr Steven Phipps.”For instance, we found that the ENSO cycle was much weaker 4300 years ago than it is today. This weaker cycle persisted for almost two centuries.”The researchers determined that natural influences on Earth’s climate, such as those caused by variations in its orbit around the sun, could affect the strength of El Niño events.Although small, these natural influences altered seasonal trade winds across the Eastern Pacific and affected the development of El Niño events. Interestingly, the research also showed that El Niño events in the past started later in the year and were often less intense.”We found there was a small strengthening of the regular seasonal trade winds in the Eastern Pacific in response to natural warming cycles in the Earth’s orbit around the sun. Remarkably this acted in a big way to stop El Niño events from forming and growing,” said lead author Dr Helen McGregor from the University of Wollongong.”This shows us that external factors can influence the ENSO process and that it may have a sustained response to future greenhouse gas changes. Currently 20th Century observations are too short to confirm whether this is occurring now.”Importantly, these new observations can now be used in climate models to see if these past changes in ENSO processes can be reproduced.”Currently, climate models do not agree on how El Niño may change under future global warming scenarios,” said Dr Phipps”With these new observations we can determine which models reproduce the most accurate response to changes in the global climate. This will help us to more accurately forecast the response of ENSO under future global warming scenarios.”

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New record for cosmic X-ray sightings: Exploring extreme universe with rich new resource

July 23, 2013 — Scientists led by the University of Leicester have set a new record for cosmic X-ray sources ever sighted — creating an unprecedented cosmic X-ray catalogue that will provide a valuable resource allowing astronomers to explore the extreme Universe.The XMM-Newton Survey Science Centre, led by a team from the University of Leicester’s Department of Physics and Astronomy, used the University’s ‘ALICE’ supercomputer to help them produce a new X-ray catalogue, dubbed “3XMM.”This new catalogue contains over half a million X-ray source detections, representing a 50% increase over previous catalogues and is the largest catalogue of X-ray sources ever produced. This vast inventory is also home to some of the rarest and most extreme phenomena in the Universe, such as tidal disruption events — when a black hole swallows another star, producing prodigious outbursts of X-ray emission.Professor Mike Watson of the University of Leicester, who leads the XMM-Newton Survey Science Centre, said: “The catalogue contains more than half a million sources, all of which are provided to a better quality than ever before.”Using the University’s £2.2m High Performance Computer meant we could process the data up to a hundred times faster than before. This was key for testing and implementing advanced new processing strategies.””The catalogue provides enormous scope for new discoveries as well as in-depth studies of large samples. XMM-Newton is pre-eminent amongst current X-ray missions in its ability to perform `survey’ science, with a chance to find previously undetected objects and then explore their properties.”The catalogue provides an exceptional dataset for generating large, well-defined samples of objects such as active galactic nuclei, clusters of galaxies, interacting compact binaries, and active stellar coronae.The XMM-Newton Survey Science Centre is one of the teams behind the European Space Agency’s (ESA) X-ray Multi-Mirror Mission (XMM-Newton). Since Earth’s atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself.The sources in the 3XMM catalogue are identified and isolated from serendipitous data recorded by XMM-Newton’s EPIC X-ray cameras, built by a team also led by the University. In each of the 600-700 observations made each year, around 70 extra sources are captured in addition to the target object which usually only takes up a small fraction of the field of view. Covering observations between February 2000 and December 2012, the catalogue contains some 531 261 X-ray source detections relating to 372 728 unique X-ray sources.Professor Watson, who is Head of X-ray and Observational Astronomy in the Department of Physics and Astronomy, adds: “The third XMM-Newton Serendipitous Source Catalogue shows how much added value can be gained from the observations. I’d like to pay tribute to the efforts of the whole team which were crucial to completing this major undertaking.”3XMM is the largest catalogue of X-ray sources ever produced. As such it offers an unparalleled resource for exploring cosmic X-ray populations, in particular in studying Active Galactic Nuclei (AGN) — those galaxies such as quasars which harbour a super-massive black hole at their centres. …

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Solar tsunami used to measure Sun’s magnetic field

July 11, 2013 — A solar tsunami observed by NASA’s Solar Dynamics Observatory (SDO) and the Japanese Hinode spacecraft has been used to provide the first accurate estimates of the Sun’s magnetic field.Solar tsunamis are produced by enormous explosions in the Sun’s atmosphere called coronal mass ejections (CMEs). As the CME travels out into space, the tsunami travels across the Sun at speeds of up to 1000 kilometres per second.Similar to tsunamis on Earth, the shape of solar tsunamis is changed by the environment through which they move. Just as sound travels faster in water than in air, solar tsunamis have a higher speed in regions of stronger magnetic field. This unique feature allowed the team, led by researchers from UCL’s Mullard Space Science Laboratory, to measure the Sun’s magnetic field. The results are outlined in a paper soon to be published in the journal Solar Physics.Dr David Long, UCL Mullard Space Science Laboratory, and lead author of the research, said: “We’ve demonstrated that the Sun’s atmosphere has a magnetic field about ten times weaker than a normal fridge magnet.”Using data obtained using the Extreme ultraviolet Imaging Spectrometer (EIS), a UK-led instrument on the Japanese Hinode spacecraft, the team measured the density of the solar atmosphere through which the tsunami was travelling.The combination of imaging and spectral observations provides a rare opportunity to examine the magnetic field which permeates the Sun’s atmosphere.Dr Long noted: “These are rare observations of a spectacular event that reveal some really interesting details about our nearest star.”Visible as loops and other structures in the Sun’s atmosphere, the Sun’s magnetic field is difficult to measure directly and usually has to be estimated using intensive computer simulations. The Hinode spacecraft has three highly sensitive telescopes, which use visible, X-ray and ultraviolet light to examine both slow and rapid changes in the magnetic field.The instruments on Hinode act like a microscope to track how the magnetic field around sunspots is generated, shapes itself, and then fades away. These results show just how sensitive these instruments can be, measuring magnetic fields that were previously thought too weak to detect.The explosions that produce solar tsunamis can send CMEs hurtling towards the Earth. Although protected by its own magnetic field, the Earth is vulnerable to these solar storms as they can adversely affect satellites and technological infrastructure.Dr Long said: “As our dependency on technology increases, understanding how these eruptions occur and travel will greatly assist in protecting against solar activity.”

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Effects of interannual climate variability on tropical tree cover: Satellite data reveal how tropical ecosystems may respond to climate extremes

June 2, 2013 — Tree cover in the tropics will likely change in surprising ways as climate change increases the frequency of extreme rainfall events, according to a study by scientists from Wageningen University published today in Nature Climate Change.The study shows that increasing year-to year variability in rainfall is associated to lower tree cover in the moist tropical forests worldwide but it can open windows of opportunity for tree expansion in some tropical drylands.”Understanding how ecosystems respond to climate variability is a priority in a fast changing globe” says Marten Scheffer, who leads the research program on tipping points. “Climate events can open windows of opportunity for abrupt changes in ecosystems. We are starting to glimpse on the complexity of these patterns” says Scheffer.”The overall effects of climate variability are puzzling. On one hand, severe drought can produce massive tree mortality, but there is also evidence of episodic tree recruitment during extreme rainy years” says Milena Holmgren, leading author of the study and a specialist on plant ecology.Satellite dataThe authors used satellite data to look at large scale patterns of tree cover across the tropics of Africa, Australia and South America. They show that increasing rainfall variability is associated to lower tree cover in the moist tropical forests of all continents. In the dry tropics, however, the effects of higher year-to year variability in rainfall depend on the specific continent. Higher overall inter-annual variation in rainfall has positive (South America), negative (Australia) or neutral effects (Africa) on tree cover in dry-lands. “The effects of climate variability in tropical drylands seem to depend on the balance between wet and dry extreme events, as well as on the opportunities trees have to grow during rainy events,” says Milena Holmgren. “We knew from small scale experiments in South America and observations in Australia that rainy years can be essential for tree recruitment in drylands. During extreme rainy years there is massive tree germination and if these young seedlings grow fast enough to escape from herbivores, then woodlands can expand. …

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