• Prehistoric climate changes still detectable deep underground

    It turns out that the steady dripping of water deep underground can reveal a surprising amount of information about the constantly changing cycles of heat and cold, precipitation and drought in the turbulent atmosphere above. As water seeps down through the ground it picks up minerals, most commonly calcium carbonate. When this mineral-rich water drips into caves, it leaves mineral deposits behind that form layers which grow during wet periods and form dusty skins when the water dries up. Today, scientists can date these layers with extreme precision based on the radioactive decay of uranium into its daughter product thorium. Variations in the thickness of the layers is determined by a combination of the amount of water seeping into the cave and the concentration of carbon dioxide in the cave’s atmosphere so, when conditions are right, they can provide a measure of how the amount of precipitation above the cave varies over time. By analyzing the ratios of heavy to light isotopes of oxygen present in the layers, the researchers can track changes in the temperature at which the water originally condensed into droplets in the atmosphere changes and whether the rainfall’s point of origin was local or if traveled a long way before falling to the ground.

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  • Can Ice Loss Affect Gravity?

    A group of scientists, led by a team from the University of Bristol, has observed a sudden increase of ice loss in a previously stable region of Antarctica. The research is published today in Science.

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  • US Exposure to Extreme Heat is on the Rise

    U.S. residents' exposure to extreme heat could increase four- to six-fold by mid-century, due to both a warming climate and a population that's growing especially fast in the hottest regions of the country, according to new research. The study, by researchers at the National Center for Atmospheric Research (NCAR) and the City University of New York (CUNY), highlights the importance of considering societal changes when trying to determine future climate impacts.

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  • Lower Ozone levels in Houston linked to climate change

    Researchers at the University of Houston have determined that climate change -- in the form of a stronger sea breeze, the result of warmer soil temperatures -- contributed to the drop in high-ozone days in the Houston area.

    Robert Talbot, professor of atmospheric chemistry, said that also should be true for coastal regions globally.

    The researchers describe their findings in a paper published this week in the journal Atmosphere. In addition to Talbot, they include first author Lei Liu, a doctoral student, and post-doctoral fellow Xin Lan.

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  • Bird populations responding to climate change

    With puzzling variability, vast numbers of birds from Canada’s boreal forests migrate hundreds or thousands of miles south from their usual winter range. These so-called irruptions were first noticed by birdwatchers decades ago, but the driving factors have never been fully explained. Now scientists have pinpointed the climate pattern that likely sets the stage for irruptions – a discovery that could make it possible to predict the events more than a year in advance.

    The researchers found that persistent shifts in rainfall and temperature drive boom-and-bust cycles in forest seed production, which in turn drive the mass migrations of pine siskins, the most widespread and visible of the irruptive migrants. “It’s a chain reaction from climate to seeds to birds,” says atmospheric scientist Court Strong, an assistant professor at the University of Utah and lead author of the study.

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  • Meet Chernobyl's Wild Residents

    It seems like a strange place to call a wildlife park: Nearly 30 years after the most catastrophic nuclear incident in global history, Chernobyl’s exclusion zone has turned into a paradise for animals of all species and sizes. A variety of raptors, deer, big cats, foxes, bears and birds have moved into the region, taking advantage of a vast habitat with almost no humans. That habitat, though, is contaminated with radioactive materials, and scientists still hotly debate the potential costs of radiation exposure to the animals of Chernobyl, some of whom have become famous.

    Researchers have seen an explosion of wildlife at the site in recent years, with camera traps providing an opportunity to look deep into the world of the region’s animals without disturbing them. Stunning photography shows animals like wolves and bears roaming freely in the exclusion zone, unconcerned about the potential for human visitors. Perhaps most astonishingly, a population of Przeswalski’s horses, an endangered species critical to the biological and evolutionary history of modern equids, is booming in the region—which isn’t exactly what one might expect, given the radioactive contamination.

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  • "Living shoreline" can enhance coastal resilience

    The resilience of U.S. coastal communities to storms, flooding, erosion and other threats can be strengthened when they are protected by natural infrastructure such as marshes, reefs, and beaches, or with hybrid approaches, such as a “living shoreline” — a combination of natural habitat and built infrastructure, according to a new NOAA study.

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  • Selective logging may underestimate carbon stock

    Up to 64 percent of above-ground biomass in selectively logged forests may consist of dead wood left over from logging damage, argues a paper published this week in Environmental Research Letters

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  • A brief history of Earth Day

    Each year, Earth Day -- April 22 -- marks the anniversary of what many consider the birth of the modern environmental movement in 1970.

    The height of hippie and flower-child culture in the United States, 1970 brought the death of Jimi Hendrix, the last Beatles album, and Simon & Garfunkel’s “Bridge Over Troubled Water”. Protest was the order of the day, but saving the planet was not the cause. War raged in Vietnam, and students nationwide increasingly opposed it.

     

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  • Lake Mead water levels continuing to drop

    The historic four-year drought in California has been grabbing the headlines lately, but there's a much bigger problem facing the West: the now 14-year drought gripping the Colorado River basin.

    One of the most stunning places to see its impact is at the nation's largest reservoir, Lake Mead, near Las Vegas. At about 40 percent of capacity, it's the lowest it's been since it was built in the 1930s.

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