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Gradual melting of winter snow helps feed water to farms, cities and ecosystems across much of the world, but this resource may soon be critically imperiled. In a new study, scientists have identified snow-dependent drainage basins across the northern hemisphere currently serving 2 billion people that run the risk of declining supplies in the coming century. The basins take in large parts of the American West, southern Europe, the Mideast and central Asia. They range from productive U.S. farm land to war-torn regions already in the grip of long-term water shortages.

Snow is an important seasonal water source mainly around large mountain chains. From higher elevations, snowmelt runs gradually into the lowlands during spring and summer growing seasons, when human demand peaks. But global warming is upsetting this convenient balance. Studies show that in many areas, more winter precipitation is falling as rain, not snow, and washing away directly; the snow that does fall is settling at progressively higher elevations, and melting earlier. The new study estimates snow’s potential to supply present human needs in both current and projected climates, taking both weather trends and population into account.

Liberia and Sierra Leone, two of the countries worst affected by the Ebola outbreak, are now virus-free according to the World Health Organisation.

On 7 November, Sierra Leone had gone 42 days without any new cases of Ebola, allowing the World Health Organisation (WHO) to declare the country free of the virus. It is an important milestone for the West African country, as the country has recorded 14,089 cases of the disease since December 2013, almost half of the total that were reported to have caused the outbreak (28,571).

Gradual melting of winter snow helps feed water to farms, cities and ecosystems across much of the world, but this resource may soon be critically imperiled. In a new study, scientists have identified snow-dependent drainage basins across the northern hemisphere currently serving 2 billion people that run the risk of declining supplies in the coming century. The basins take in large parts of the American West, southern Europe, the Mideast and central Asia. They range from productive U.S. farm land to war-torn regions already in the grip of long-term water shortages.

Snow is an important seasonal water source mainly around large mountain chains. From higher elevations, snowmelt runs gradually into the lowlands during spring and summer growing seasons, when human demand peaks. But global warming is upsetting this convenient balance. Studies show that in many areas, more winter precipitation is falling as rain, not snow, and washing away directly; the snow that does fall is settling at progressively higher elevations, and melting earlier. The new study estimates snow’s potential to supply present human needs in both current and projected climates, taking both weather trends and population into account.

La acidificación del suelo de la lluvia ácida que es perjudicial para las plantas y la vida acuática ya ha comenzado a revertir en los bosques del noreste de Estados Unidos y el este de Canadá, de acuerdo con una colaboración estadounidense-canadiense de cinco instituciones dirigidas por el Servicio Geológico de Estados Unidos (USGS por sus siglas en inglés)

La nueva investigación muestra que estos cambios están estrechamente vinculados a la disminución de lluvia ácida, aunque algunos resultados difieren de las respuestas esperadas.

Indeed, museum collections are fascinating. Many of us probably still gawk at stuffed collections of extant and extinct birds, beetles, vibrantly-colored butterflies, and other animals that fill up glass cases and exhibition halls. Many of these collections were borne out of expeditions to remote parts of the world; treks that involved trapping, killing, preserving and cataloging animals that explorers encountered. Many of these collections have been useful in shaping what we know of the natural world. However, species conservation or scientific advancement was not always the goal of animal-collection. Often, it was done simply to suit the aesthetic whims of society’s elite.