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Major reductions in seafloor marine life from climate change by 2100

A new study quantifies for the first time future losses in deep-sea marine life, using advanced climate models. Results show that even the most remote deep-sea ecosystems are not safe from the impacts of climate change.

An international team of scientists predict seafloor dwelling marine life will decline by up to 38 per cent in the North Atlantic and over five per cent globally over the next century. These changes will be driven by a reduction in the plants and animals that live at the surface of the oceans that feed deep-sea communities. As a result, ecosystem services such as fishing will be threatened.

In the study, led by the National Oceanography Centre, the team used the latest suite of climate models to predict changes in food supply throughout the world oceans. They then applied a relationship between food supply and biomass calculated from a huge global database of marine life.

The results of the study are published this week in the scientific journal Global Change Biology.

These changes in seafloor communities are expected despite living on average four kilometres under the surface of the ocean. This is because their food source, the remains of surface ocean marine life that sink to the seafloor, will dwindle because of a decline in nutrient availability. Nutrient supplies will suffer because of climate impacts such as a slowing of the global ocean circulation, as well as increased separation between water masses -- known as 'stratification' -- as a result of warmer and rainier weather.

Lead author Dr Daniel Jones says: "There has been some speculation about climate change impacts on the seafloor, but we wanted to try and make numerical projections for these changes and estimate specifically where they would occur.

"We were expecting some negative changes around the world, but the extent of changes, particularly in the North Atlantic, were staggering. Globally we are talking about losses of marine life weighing more than every person on the planet put together."

The projected changes in marine life are not consistent across the world, but most areas will experience negative change. Over 80 per cent of all identified key habitats -- such as cold-water coral reefs, seamounts and canyons -- will suffer losses in total biomass. The analysis also predicts that animals will get smaller. Smaller animals tend to use energy less efficiently, thereby impacting seabed fisheries and exacerbating the effects of the overall declines in available food.

The study was funded by the Natural Environment Research Council (NERC) as part of the Marine Environmental Mapping Programme (MAREMAP), and involved researchers from the National Oceanography Centre, the Memorial University of Newfoundland, Canada, the University of Tasmania, and the Laboratoire des Sciences du Climat et de l'Environnement, France.


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As the temperature drops, risk of fracture rises

Record-setting winter weather in the U.S. has led to lots of road condition advisories, but could there also be a slip and fall alert?

By analyzing various conditions -- like snow, wind speed, temperature -- into a 'Slipperiness Score,' a University of Michigan Health System study helps identify what days are the most risky for slip and fall injuries.

The study, published in February's Plastic and Reconstructive Surgery Journal, focuses on Medicare patients, all over age 65, but authors note, the risk of falling exists for anyone during harsh winter weather.

"Although the concept that slippery footing increases your risk of falling isn't new, what we've been able to show is that these dangerous conditions result in more fractures in this already vulnerable population of adults," says lead study author Aviram Giladi, M.D., a resident in the U-M Department of Surgery's Division of Plastic Surgery.

The study findings include:

Based on a scale, ranging from 0 to 7, on a day with a score above 4 the risk of sustaining a wrist fracture increased by 21 percent.On the most slippery days, that additional risk went up to nearly 40 percent.In the winter, over 1,000 additional wrist fractures occurred among adults age 65 and older compared to other seasons.

Nearly 90,000 Medicare enrollees sustain wrist fractures each year, frequently from falls while standing and usually outdoors. The fractures can be quite limiting, and lead to a loss of independence for older patients. Medicare spends more than $240 million a year treating the injuries.

"Understanding the risk of these injuries can help inform prevention and preparation efforts, especially on days where the weather is bound to result in more slippery conditions," says senior study author Kevin C. Chung, M.D., professor of plastic surgery and orthopedic surgery and the Charles B. G. de Nancrede Professor of Surgery. "We hope to help people prepare for risky conditions and adjust where and when they walk outdoors."

Journal Reference:

Aviram M. Giladi, Melissa J. Shauver, Allison Ho, Lin Zhong, H. Myra Kim, Kevin C. Chung. Variation in the Incidence of Distal Radius Fractures in the U.S. Elderly as Related to Slippery Weather Conditions. Plastic and Reconstructive Surgery, 2014; 133 (2): 321 DOI: 10.1097/01.prs.0000436796.74305.38

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Clues to how plants evolved to cope with cold

Researchers have found new clues to how plants evolved to withstand wintry weather. In a study to appear in the December 22 issue of the journal Nature, the team constructed an evolutionary tree of more than 32,000 species of flowering plants -- the largest time-scaled evolutionary tree to date. By combining their tree with freezing exposure records and leaf and stem data for thousands of species, the researchers were able to reconstruct how plants evolved to cope with cold as they spread across the globe. The results suggest that many plants acquired characteristics that helped them thrive in colder climates -- such as dying back to the roots in winter -- long before they first encountered freezing.

Fossil evidence and reconstructions of past climatic conditions suggest that early flowering plants lived in warm tropical environments, explained co-author Jeremy Beaulieu at the National Institute for Mathematical & Biological Synthesis (NIMBioS) at the University of Tennessee.

As plants spread to higher latitudes and elevations, they evolved in ways that helped them deal with cold conditions. Plants that live in the tundra, such as Arctic cinquefoil and three-toothed saxifrage, can withstand winter temperatures below minus 15 degrees Celsius.

Unlike animals, most plants can't move to escape the cold or generate heat to keep them warm. It's not so much the cold but the ice that poses problems for plants. For instance, freezing and thawing cause air bubbles to form in the plant's internal water transport system.

"Think about the air bubbles you see suspended in the ice cubes," said co-author Amy Zanne of the George Washington University. "If enough of these air bubbles come together as water thaws they can block the flow of water from the roots to the leaves and kill the plant."

The researchers identified three traits that help plants get around these problems.

Some plants, such as hickories and oaks, avoid freezing damage by dropping their leaves before the winter chill sets in -- effectively shutting off the flow of water between roots and leaves -- and growing new leaves and water transport cells when warmer weather returns.

Other plants, such as birches and poplars, also protect themselves by having narrower water transport cells, which makes the parts of the plant that deliver water less susceptible to blockage during freezing and thawing.

Still others die back to the ground in winter and re-sprout from their roots, or start growing as new plants from seeds when conditions are right.

To compile the plant trait data for their study, the researchers spent hundreds of hours scouring and merging multiple large plant databases containing tens of thousands of species, largely with the support of the National Evolutionary Synthesis Center in North Carolina and Macquarie University in Australia.

When they mapped their collected leaf and stem data onto their evolutionary tree for flowering plants, they found that many plants were well equipped for icy climates even before cold conditions hit.

Plants that die back to the ground in winter, for example, acquired the ability to die and come back when conditions improve long before they first experienced freezing. Similarly, species with narrow water transport cells acquired a finer circulatory system well before they confronted cold climates.

"This suggests that some other environmental pressure -- possibly drought -- caused these plants to evolve this way, and it happened to work really well for freezing tolerance too," said Zanne.

The only exceptions were plants that shed and replace their leaves seasonally -- these plant groups didn't gain the ability to drop their leaves during winter until after they encountered freezing, Beaulieu added.

As a next step, the researchers plan to use their evolutionary tree to find out how plants evolved to withstand other environmental stresses in addition to freezing, such as drought and heat.


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Climate change threatens Winter Olympics: Only six of previous Winter Games venues to be cold enough by late-century

Only six of the previous Winter Olympics host cities will be cold enough to reliably host the Games by the end of this century if global warming projections prove accurate.

Even with conservative climate projections, only 11 of the previous 19 sites could host the Games in the coming decades, according to a new study from the University of Waterloo (Canada) and Management Center Innsbruck (Austria).

"The cultural legacy of the world's celebration of winter sport is increasingly at risk," said Professor Daniel Scott, a Canada Research Chair in Global Tourism and lead author of the study. "Fewer and fewer traditional winter sports regions will be able to host a Olympic Winter Games in a warmer world."

The study finds that internationally renowned Olympic sites, such as Squaw Valley (USA), Garmisch-Partenkirchen (Germany), Vancouver (Canada) and Sochi (Russia) would no longer have climates suitable to reliably host the Games by the middle of the 21st century. With additional warming projected for later decades of this century, as few as six former host locations would remain climatically suitable.

"This report clearly points out the challenges that lie ahead for the Olympics because of climate change," said Chris Steinkamp, executive director of Protect Our Winters and who was not involved with the study. "It's particularly powerful to see how past Olympic host cities could be impacted under a higher emission scenario, so hopefully this will serve as a wake up call to the IOC and world leaders that major commitments to carbon reductions need to be made."

The need for weather risk management strategies by Olympic organizers has intensified as the average February daytime temperature of Winter Games locations has steadily increased -- from 0.4?C at Games held in the 1920-50s, to 3.1?C in Games during the 1960-90s, and 7.8?C in Games held in the 21st century.

"Today it would be difficult to imagine successfully delivering the diverse Games program exclusively on natural ice and snow, as it was in the early decades of the Olympic Winter Games," said Dr. Robert Steiger of the Management Center Innsbruck.

Weather risk management will become even more important in the coming decades with average February temperatures in past Winter Olympic host locations expected to warm an additional 1.9 to 2.1?C by mid-century and 2.7 to 4.4?C in late century.

The study found that the success of the Games is often partially attributed to favourable weather, while poor weather is highlighted as one of the greatest challenges faced by Olympic Organizing Committees. Weather affects the ability to prepare for the Games and can directly impact outdoor opening and closing ceremonies, fairness of outdoor competitions, spectator comfort, transportation, and visibility and timing of television broadcasts.

The study also examines how technological advancements and strategies developed over several decades have been used to manage weather risk at the Winter Olympics. Technology like snowmaking, track/jump refrigeration and high-resolution weather forecasting are now critical components of staging a successful Winter Games.

"Despite technological advances, there are limits to what current weather risk management strategies can cope with," said Professor Scott. "By the middle of this century, these limits will be surpassed in some former Winter Olympic host regions."

The study provides an important opportunity for reflection on the long-term implications of global climate change for the world of sport and the world's collective cultural heritage symbolized by the Olympic Movement. It also reveals that for some cities and regions interested in hosting a future Winter Olympics, the time to bid for the games might be sooner than later.

Report: https://uwaterloo.ca/news/sites/ca.news/files/uploads/files/oly_winter_games_warmer_world_2014.pdf


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