Extreme weather caused by climate change decides distribution of insects, study shows

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As climate change is progressing, the temperature of our planet increases. This is particularly important for the large group of animals that are cold-blooded (ectothermic), including insects. Their body temperature is ultimately determined by the ambient temperature, and the same therefore applies to the speed and efficiency of their vital biological processes.But is it changes in average temperature or frequency of extreme temperature conditions that have the greatest impact on species distribution? This was the questions that a group of Danish and Australian researchers decided to examine in a number of insect species.Johannes Overgaard, Department of Bioscience, Aarhus University, Denmark, Michael R. Kearney and Ary A. Hoffmann, Melbourne University, Australia, recently published the results of these studies in the journal Global Change Biology. The results demonstrate that it is especially the extreme temperature events that define the distribution of both tropical and temperate species. Thus climate change affects ectotermic animals primarily because more periods of extreme weather are expected in the future.Fruit flies were modeledThe researchers examined 10 fruit fly species of the genus Drosophila adapted to tropical and temperate regions of Australia. First they examined the temperatures for which the species can sustain growth and reproduction, and then they found the boundaries of tolerance for hot and cold temperatures.”This is the first time ever where we have been able to compare the effects of extremes and changes in average conditions in a rigorous manner across a group of species,” mentions Ary Hoffmann.Based on this knowledge and knowledge of the present distribution of the 10 species they then examined if distribution was correlated to the temperatures required for growth and reproduction or rather limited by their tolerance to extreme temperature conditions.”The answer was unambiguous: it is the species’ tolerance to very cold or hot days that define their present distribution,” says Johannes Overgaard.It is therefore the extreme weather events, such as heat waves or extremely cold conditions, which costs the insects their life, not an increase in average temperature.Drastic changes in storeWith this information in hand, the researchers could then model how distributions are expected to change if climate change continues for the next 100 years.Most terrestrial animals experience temperature variation on both daily and seasonal time scale, and they are adapted to these conditions. Thus, for a species to maintain its existence under varying temperature conditions there are two simple conditions that must be met. …


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#Alternative-Medicine, #Australia, #Decades, #Events, #Health, #Kilometers, #Melbourne, #Planet, #Result, #Species, #Study, #University

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

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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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#Cancer, #Climate, #Extreme, #Extremeweather, #Floods, #Health, #News, #Planet, #Pregnancy, #Research, #Science

Responding to potential asteroid redirect mission targets

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One year ago, on Feb. 15, 2013, the world was witness to the dangers presented by near-Earth Objects (NEOs) when a relatively small asteroid entered Earth’s atmosphere, exploding over Chelyabinsk, Russia, and releasing more energy than a large atomic bomb. Tracking near-Earth asteroids has been a significant endeavor for NASA and the broader astronomical community, which has discovered 10,713 known near-Earth objects to date. NASA is now pursuing new partnerships and collaborations in an Asteroid Grand Challenge to accelerate NASA’s existing planetary defense work, which will help find all asteroid threats to human population and know what to do about them. In parallel, NASA is developing an Asteroid Redirect Mission (ARM) — a first-ever mission to identify, capture and redirect an asteroid to a safe orbit of Earth’s moon for future exploration by astronauts in the 2020s.ARM will use capabilities in development, including the new Orion spacecraft and Space Launch System (SLS) rocket, and high-power Solar Electric Propulsion. All are critical components of deep-space exploration and essential to meet NASA’s goal of sending humans to Mars in the 2030s. The mission represents an unprecedented technological feat, raising the bar for human exploration and discovery, while helping protect our home planet and bringing us closer to a human mission to one of these intriguing objects.NASA is assessing two concepts to robotically capture and redirect an asteroid mass into a stable orbit around the moon. In the first proposed concept, NASA would capture and redirect an entire very small asteroid. In the alternative concept, NASA would retrieve a large, boulder-like mass from a larger asteroid and return it to this same lunar orbit. In both cases, astronauts aboard an Orion spacecraft would then study the redirected asteroid mass in the vicinity of the moon and bring back samples.Very few known near-Earth objects are ARM candidates. …


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#Atomic, #Defense, #Nasa, #Objectprogram, #Orbit, #Planet, #Program, #Result, #Space

Flowing water on Mars appears likely but hard to prove: Studies examine puzzling summertime streaks

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Martian experts have known since 2011 that mysterious, possibly water-related streaks appear and disappear on the planet’s surface. Georgia Institute of Technology Ph.D. candidate Lujendra Ojha discovered them while an undergraduate at the University of Arizona. These features were given the descriptive name of recurring slope lineae (RSL) because of their shape, annual reappearance and occurrence generally on steep slopes such as crater walls. Ojha has been taking a closer look at this phenomenon, searching for minerals that RSL might leave in their wake, to try to understand the nature of these features: water-related or not?Ojha and Georgia Tech Assistant Professor James Wray looked at 13 confirmed RSL sites using Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) images. They didn’t find any spectral signature tied to water or salts. But they did find distinct and consistent spectral signatures of ferric and ferrous minerals at most of the sites. The minerals were more abundant or featured distinct grain sizes in RSL-related materials as compared to non-RSL slopes.”We still don’t have a smoking gun for existence of water in RSL, although we’re not sure how this process would take place without water,” said Ojha. “Just like the RSL themselves, the strength of the spectral signatures varies according to the seasons. The signatures are stronger when it’s warmer and less significant when it’s colder.”The research team also notes that the lack of water-related absorptions rules out hydrated salts as a spectrally dominant phase on RSL slopes. …


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#Alzheimer, #Crater, #Crism, #Dra, #Institute, #Planet, #Rsl, #Streaks, #Walls