In ancient Earth history, the sun burned as much as 30 percent dimmer than it does now. Theoretically that should have encased the planet in ice, but there is geologic evidence for rivers and ocean sediments between 2 billion and 4 billion years ago.
Scientists have speculated that temperatures warm enough to maintain liquid water were the result of a much thicker atmosphere, high concentrations of greenhouse gases or a combination of the two. (more…)
*Scientists looked back in time–in the geologic record–to see the future*
Even if humankind manages to limit global warming to 2 degrees Celsius (3.6 degrees Fahrenheit)–as the Intergovernmental Panel on Climate Change recommends–future generations will likely have to deal with a completely different world.
One with sea levels 40 to 70 feet higher than at present, according to research results published this week in the journal Geology. (more…)
Mesquite trees and woody shrubs are better adapted than grasslands to a Southwestern climate predicted to shift toward higher temperatures and greater variability in rainfall, UA ecologists have discovered.
As the desert Southwest becomes hotter and drier, semi-arid grasslands are slowly being replaced by a landscape dominated by mesquite trees, such as Prosopis velutina, and other woody shrubs, a team of University of Arizona researchers has found.
In a “leaf-to-landscape” approach, the team combined physiological experiments on individual plants and measurements across entire ecosystems to quantify how well grasslands, compared to mesquite trees and woody shrubs, cope with heat and water stress across seasonal precipitation periods. (more…)
When Sifrhippus sandae, the earliest known horse, first appeared in the forests of North America more than 50 million years ago, it would not have been mistaken for a Clydesdale.
It weighed in at around 12 pounds–and it was destined to get much smaller over the ensuing millennia.
Sifrhippus lived during the Paleocene-Eocene Thermal Maximum (PETM), a 175,000-year interval of time some 56 million years ago in which average global temperatures rose by about 10 degrees Fahrenheit. (more…)
*History of influence of industrial revolution hidden in glacial ice*
New clues about how Earth’s remote ecosystems have been influenced by the industrial revolution have been uncovered. Until now they were locked away, frozen in the ice of glaciers.
So say scientist Aron Stubbins of the Skidaway Institute of Oceanography and colleagues. (more…)
*Findings further efforts to better predict geomagnetic storms in space*
UCLA researchers have explained the puzzling disappearing act of energetic electrons in Earth’s outer radiation belt, using data collected from a fleet of orbiting spacecraft.
In a paper published Jan. 29 in the advance online edition of the journal Nature Physics, the team shows that the missing electrons are swept away from the planet by a tide of solar wind particles during periods of heightened solar activity. (more…)
WASHINGTON, D.C. — Measurable improvements in air quality and visibility, human health, and water quality in many acid-sensitive lakes and streams, have been achieved through emissions reductions from electric generating power plants and resulting decreases in acid rain. These are some of the key findings in a report to Congress by the National Acid Precipitation Assessment Program, a cooperative federal program.
The report shows that since the establishment of the Acid Rain Program, under Title IV of the 1990 Clean Air Act Amendments, there have been substantial reductions in sulfur dioxide (SO2) and nitrogen oxides (NOx) emissions from power plants that use fossil fuels like coal, gas and oil, which are known to be the primary causes of acid rain. As of 2009, emissions of SO2 and NOx declined by about two-thirds relative to levels in the 1990s. These emissions levels declined even further in 2010, according to recent data compiled by the U.S. Environmental Protection Agency. (more…)
Susan Gibbons began a five-year term as University librarian in July 2011. In that role, she oversees one of the largest university libraries in North America, which includes over 12.5 million volumes housed in 18 different libraries.
Before coming to Yale, Gibbons worked at the University of Rochester, where she began as digital initiatives librarian in 2000. In 2008, she was appointed vice provost and dean of the River Campus Libraries.
Gibbons took time out of her hectic schedule to meet with YaleNews. The following is an edited transcript of that conversation. (more…)
