How does your green roof garden grow?

UNIVERSITY PARK, PA -- Growing plants on rooftops is an old concept that has evolved from simple sod roofing to roof gardens and new, lightweight "extensive green roofs". Modern green roofs have environmental and social benefits; they can reduce stormwater runoff, improve air quality, mitigate urban heat, reduce the demand for air conditioning and greenhouse gas emissions, and provide habitat for birds and wildlife. Long-used in urban planning in Europe, green roofs are becoming more popular in North America, and new research designed to promote the integration of green roofs into current and future buildings is burgeoning. Researchers from the Department of Horticulture at The Pennsylvania State University published a study in HortTechnology that evaluated the influence of substrate type and depth on establishment of five common green roof plants.

Plants suitable for extensive green roofs must tolerate extreme rooftop conditions, and the substrates in which they grow must meet both horticultural and structural requirements. Deeper substrates may retain more water for plants during dry periods, but they also weigh more, especially when near saturation. The study by Christine E. Thuring, Robert D. Berghage, and David J. Beattie was designed to evaluate the effects of substrate type and depth on the establishment and early growth of five plants popular in North American green roof designs.

New technology to speed cleanup of nuclear-contaminated sites

CORVALLIS, Ore. – Members of the engineering faculty at Oregon State University have invented a new type of radiation detection and measurement device that will be particularly useful for cleanup of sites with radioactive contamination, making the process faster, more accurate and less expensive.
A patent has been granted on this new type of radiation spectrometer, and the first production of devices will begin soon. The advance has also led to creation of a Corvallis-based spinoff company, Avicenna Instruments, based on the OSU research. The market for these instruments may ultimately be global, and thousands of them could be built, researchers say.
Hundreds of millions of dollars are spent on cleanup of some major sites contaminated by radioactivity, primarily from the historic production of nuclear weapons during and after World War II. These include the Hanford site in Washington, Savannah River site in South Carolina, and Oak Ridge National Laboratory in Tennessee.

Broken glass yields clues to climate change

A study appearing this week in Proceedings of the National Academy of Sciences finds that microscopic particles of dust, emitted into the atmosphere when dirt breaks apart, follow similar fragment patterns to broken glass and other brittle objects. The research, by National Center for Atmospheric Research (NCAR) scientist Jasper Kok, suggests there are several times more dust particles in the atmosphere than previously thought, since shattered dirt appears to produce an unexpectedly high number of large dust fragments.
The finding has implications for understanding future climate change because dust plays a significant role in controlling the amount of solar energy in the atmosphere. Depending on their size and other characteristics, some dust particles reflect solar energy and cool the planet, while others trap energy as heat.

Growing hypoxic zones reduce habitat for billfish and tuna

Billfish and tuna, important commercial and recreational fish species, may be more vulnerable to fishing pressure because of shrinking habitat, according to a new study published by scientists from NOAA, The Billfish Foundation, and University of Miami Rosenstiel School of Marine and Atmospheric Science.
An expanding zone of low oxygen, known as a hypoxic zone, in the Atlantic Ocean is encroaching upon these species' preferred oxygen-abundant habitat, forcing them into shallower waters where they are more likely to be caught.
During the study, published recently in the journal Fisheries Oceanography, scientists tagged 79 sailfish and blue marlin with satellite tracking devices in the western North Atlantic, off south Florida and the Caribbean; and eastern tropical Atlantic, off the coast of West Africa. The pop off archival satellite tags monitored horizontal and vertical movement patterns. Researchers confirmed that billfish prefer oxygen rich waters closer to the surface and will actively avoid waters low in oxygen.

The ethics of biofuels

In the world-wide race to develop energy sources that are seen as "green" because they are renewable and less greenhouse gas-intensive, sometimes the most basic questions remain unanswered.
In a paper released today by the School of Public Policy at the University of Calgary, authors Michal Moore, Senior Fellow, and Sarah M. Jordaan at Harvard University in the Department of Earth and Planetary Sciences, look at the basic question of whether these energy sources are ethical.
In addition to arguing that the greenhouse gas benefits of biofuel are overstated by many policymakers, the authors argue that there are four questions that need to be considered before encouraging and supporting the production of more biofuel.

Conditioning reefs for the future

In a world first, a new 'state of the art' climate change experimental facility has been completed at the University of Queensland's Heron Island Research Station.
The Climate Change Mesocosm (CCM) project led by Associate Professor Sophie Dove and Dr. David Kline from the Global Change Institute's Coral Reef Ecosystems Laboratory is one of the largest and most accurately controlled ocean acidification and warming experimental systems in the world and simulates ocean temperatures and acidification levels predicted to occur on coral reefs in the next 50 to 100 years.
Able to regulate both temperature and CO₂ levels prescribed by the 2100 IPCC scenarios in a highly controlled environment, the CCM system allows studies of climate change from the molecular to the ecosystem level.

Scientists: The fire in Israel is a typical example of climate change effects in the Mediterranean

According to "Israel’s National Report on Climate Change", prepared by Pe’er and other members of Ben-Gurion University of the Negev on behalf of the Israeli Ministry of the Environmental Protection, the frequency, intensity and extent of the fires would increase due to the prolongation of droughts, increase in water evaporation and an increased frequency of intense heat waves. At a warming of 1.5 degrees by the year 2100, which is by now considered a conservative scenario, models predict the desert to expand northward by 300 to 500 kilometers to the north. Mediterranean ecosystems, such as the one occurring in the Carmel Mountains, would thus disappear from Israel. Forest fires in the Carmel mountain range in northern Israel was preceded by eight months of drought and occurred during a heat wave with temperatures around 30ºC. Normally, first rainfall should have come in September or October, and the maximal daily temperature at this time of year should be around 15-20ºC.

Electrified nano filter promises to cut costs for clean drinking water

With almost one billion people lacking access to clean, safe drinking water, scientists are reporting development and successful initial tests of an inexpensive new filtering technology that kills up to 98 percent of disease-causing bacteria in water in seconds without clogging. A report on the technology appears in Nano Letters, a monthly American Chemical Society journal.
Yi Cui and colleagues explain that most water purifiers work by trapping bacteria in tiny pores of filter material. Pushing water through those filters requires electric pumps and consumes a lot of energy. In addition, the filters can get clogged and must be changed periodically. The new material, in contrast, has relatively huge pores, which allow water to flow through easily. And it kills bacteria outright, rather than just trapping them.

Neglected greenhouse gas discovered by atmosphere chemists

One kilo of anaesthetic gas affects the climate as much as 1620 kilos of CO2. That has been shown by a recent study carried out by chemists from University of Copenhagen and NASA in collaboration with anaesthesiologists from the University of Michigan Medical School. The amount of gas needed for a single surgical procedure is not high, but in the US alone surgery related anaesthetics affected the climate as much as would one million cars.Tænk før bedøvelse 
Analyses of the anaesthetics were carried out by Ole John Nielsen. He is a Professor of atmospheric chemistry at the University of Copenhagen, and he's got an important message for doctors.
"We studied three different gasses in regular use for anaesthesia, and they're not equally harmful," explains Professor Nielsen