The Antarctic shore is a place of huge contrasts, as quiet, dark, and frozen winters give way to bright, clear waters, thick with algae and peppered with drifting icebergs in summer. But as the planet has warmed in the last two decades, massive losses of sea ice in winter have left icebergs free to roam for most of the year. As a result, say researchers reporting in the Cell Press journal Current Biology on June 16, boulders on the shallow seabed -- once encrusted with a rich assemblage of species in intense competition for limited space -- now mostly support a single species. The climate-linked increase in iceberg activity has left all other species so rare as to be almost irrelevant.
"The Antarctic Peninsula can be considered an early warning system -- like a canary in a coal mine," says David Barnes of the British Antarctic Survey. "Physical changes there are amongst the most extreme and the biology considered quite sensitive, so it was always likely to be a good place to observe impacts of climate change -- but impacts elsewhere are likely to be not too far behind. A lot of the planet depends on the near-shore environment, not least for food; what happens there to make it less stable is important."
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Con temperaturas de verano acercándose rápidamente, los hogares de todo el paÃs están instalando y preparando unidades de aire acondicionado en previsión de un clima caliente y sudoroso.
Sin embargo, un ciclo potencialmente brutal puede estar a la espera si se proyectan dÃas de verano de extremo calor con más frecuencia e intensidad como resultado del cambio climático.
Según un nuevo estudio realizado en Phoenix por investigadores de la Universidad Estatal de Arizona, el calor desperdiciado que es emitido por unidades de aire acondicionado en realidad, ¡aumentan la temperatura del aire libre de la ciudad en la noche por 1 hasta 2.7 grados! En consecuencia, estas temperaturas más cálidas pueden alentar a las personas a incrementar su demanda y uso de energÃa para sus equipos de aire acondicionado.
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A clinical trial involving nearly 300 men and women residing in one of China's most polluted regions found that daily consumption of a half cup of broccoli sprout beverage produced rapid, significant and sustained higher levels of excretion of benzene, a known human carcinogen, and acrolein, a lung irritant.
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You could say that, at least until now, cars and tomatoes have basically nothing in common. Tomatoes go from green to red as they ripen, and cars, well, they seem to be getting greener. As part of this trend, Ford is one of several companies that have been pursuing a viable bio-based plastic that could substitute for the petroleum-based plastics that dominate the industry today. Indeed, as cars continue to reduce vehicle weight in order to improve fuel economy, the use of plastics is becoming ever more common.
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La Agencia de Protección Ambiental de Estados Unidos (FDA) y la Administración de Alimentos y Narcóticos (FDA) emitieron hoy el proyecto de asesoramiento actualizado sobre el consumo de pescado. Las dos agencias han concluido que las mujeres embarazadas y lactantes, aquellas que podrÃan quedar embarazadas y los niños pequeños deben comer más pescado que sea bajo en mercurio a fin de obtener importantes beneficios de salud y de desarrollo. El proyecto de asesoramiento actualizado se ajusta a las recomendaciones de las GuÃas Alimentarias para los Estadounidenses 2010.
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