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Most U.S. rooftops in good repair can take the weight of solar photovoltaic (PV) systems. That’s the conclusion of a three-year study by a research team led by Sandia National Laboratories.

“There is a misperception in the building industry that existing residential rooftops lack the strength to carry the weight load of rooftop solar photovoltaic installations,” said Sandia structural engineer Steve Dwyer. “Most existing well-built wooden rooftops can support PV system loads.”

Sandia took on the job of analyzing rooftop structural strength to address concerns raised in the U.S. Department of Energy’s (DOE) Solar America Cities program. The agency named 25 cities to promote adoption of solar technology at a comprehensive, local level through photovoltaics.

The climate talks that concluded last December were a great success, but it will be decades before we can judge whether the Paris Agreement itself is ultimately successful. What can be said is that the accord provides a good foundation for meaningful progress on climate change, and represents a dramatic departure from the past 20 years of climate negotiations.

I have long viewed the dichotomous distinction between Annex I and non–Annex I countries in the Kyoto Protocol as the major stumbling block to progress. The protocol included mandatory emissions-reduction obligations for developed countries, but none for developing countries. That made progress impossible, because significant growth in emissions since the protocol came into force in 2005 has been entirely in the large developing countries — China, India, Brazil, South Korea, South Africa, Mexico, and Indonesia.

The globally increasing light pollution has negative effects on organisms and entire ecosystems. The consequences are especially hard on nocturnal insects, since their attraction to artificial light sources generally ends fatal. A new study by Swiss zoologists from the Universities of Basel and Zurich now shows that urban moths have learned to avoid light. The journal Biology Letters has published their results.

Some insects are attracted by light while others shy away from it. Proverbial is the attraction light has on moths. Street lamps and other artificial light sources often become death traps for nocturnal insects such as moths. Either they die through direct burning or through increased exposure to predators. Mortality of urban insects can thus be 40- to 100- fold higher than in rural populations.

El musgo que crece en los árboles urbanos es un bio-indicador útil de la contaminación del aire por cadmio en Portland, Oregón, según un estudio dirigido Estación de Investigación Forestal de EE.UU. Servicio del Noroeste del Pacífico. El trabajo, el primero en utilizar el musgo para generar un mapa riguroso y detallado de la contaminación del aire en una ciudad EE.UU., se publica en línea en la revista Science of the Total Environment.

People who reported consuming more fast food in a national survey were exposed to higher levels of potentially harmful chemicals known as phthalates, according to a study published today by researchers at Milken Institute School of Public Health (Milken Institute SPH) at the George Washington University. The study, one of the first to look at fast-food consumption and exposure to these chemicals, appears in the journal Environmental Health Perspectives.