Wildlife in Yellowstone National Park is undergoing dramatic shifts with consequences that are beginning to return the landscape to conditions not seen in nearly a century, according to a series of new studies.
In the park's northeast section, elk have decreased in number in their historic winter range in the Lamar Valley and are now more numerous outside the park. This change in elk numbers and distribution can be traced back to the reintroduction of wolves in 1995-96. Scientists have hypothesized that wolves affect both the numbers and the behavior of elk, thereby reducing the impact of browsing on vegetation, a concept known as a "trophic cascade."
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Global temperature is likely to rise 3.3-5.6 degrees Celsius by the end of this century, unless international climate negotiations in Paris next year are more effective than expected, according to a report released Monday by the MIT Joint Program on the Science and Policy of Global Change. The predicted temperature increase surpasses the threshold identified by the United Nations as necessary to avoid the most serious impacts of climate change, altering precipitation patterns and heightening the pressures of population and economic growth.
"Our world is rapidly changing," says John Reilly, co-director of the MIT Joint Program and a coauthor of the report. "We need to understand the nature of the risks we’re facing so we can prepare for them."
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Advocates of nuclear energy have long been predicting its renaissance, yet this mode of producing electricity has been stalled for years. Renewable energy, by contrast, continues to expand rapidly, even if it still has a long way to go to catch up with fossil fuel power plants, writes Worldwatch Institute Senior Researcher Michael Renner in the Institute’s latest Vital Signs Online analysis (bit.ly/NuclearRE).
Nuclear energy’s share of global power production has declined steadily from a peak of 17.6 percent in 1996 to 10.8 percent in 2013. Renewables increased their share from 18.7 percent in 2000 to 22.7 percent in 2012.
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Cooking with gas is preferred by many cooks to alternatives. The popularity of "professional" stoves and cooktops with high-output burners makes cooking more fun perhaps, but those high-output burners also put out more contaminants. It is important to recognize this and to properly ventilate the cooking area with a hood that vents to the outside, or even a fan through the kitchen wall, or even a window. A new study by Oregon State University recommends that parents with children at home should use ventilation when cooking with a gas stove, after a new study showed an association between gas kitchen stove ventilation and asthma, asthma symptoms and chronic bronchitis.
"In homes where a gas stove was used without venting, the prevalence of asthma and wheezing is higher than in homes where a gas stove was used with ventilation," said Ellen Smit, an associate professor in the College of Public Health and Human Sciences at OSU and one of the study’s authors. “Parents of all children should use ventilation while using a gas stove."
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Tropical forest restoration projects are exciting research sites for scientists studying factors that affect ecosystem recovery. Here, scientists are trying to understand plant community succession, i.e. the process of recovery after cleared lands are abandoned and allowed to regrow naturally. One of the most important components of this recovery process is seed dispersal, since seeds from nearby forests allow a deforested habitat to become populated again by native plants and trees.
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