Astronomers discover two new worlds orbiting ancient star next door

An international team of astronomers, including five Carnegie scientists, reports the discovery of two new planets orbiting a very old star that is near to our own Sun. One of these planets orbits the star at the right distance to allow liquid water to exist on its surface, a key ingredient to support life.

Water goes 'missing' with snow loss

 A new study finds that if temperatures rise and more precipitation falls as rain rather than snow, it will reduce the total amount of water in rivers.

It is a surprising observation. One might expect the timing of water flow to change but not the overall volume.

The researchers report their work in the journal Nature Climate Change.

Environmental conditions may impact bird migration

Wind conditions during spring migration may be a predictor of apparent annual survival and the timing of breeding in yellow warblers, according to results published May 14, 2014, in the open access journal PLOS ONE by Anna Drake from Simon Fraser University, Canada and colleagues.

Migratory birds play a critical role in the ecosystem, pollinating plants, dispersing seeds, and consuming insects and small mammals. Yellow warblers breed in western Canada and overwinter in Mexico, making them difficult to study during all stages of their annual cycle. Scientists used data collected from 380 birds over seven breeding seasons to examine how climatic conditions during the winter migratory and breeding season influenced survival and reproduction. They found that of the climatic models tested, wind speeds on migration best predicted apparent annual adult survival, male arrival date at the breeding site, female egg laying, and annual productivity.

Air pollution 'too high' in most of world's cities

Air pollution in cities such as Delhi is exceeding safe levels, the WHO says

The World Health Organization says air pollution in many of the world's cities is breaching its guidelines.

Its survey of 1,600 cities in 91 countries revealed that nearly 90% of people in urban centers breathe air that fails to meet levels deemed safe.

The WHO says that about half of the world's urban population is exposed to pollution at least 2.5 times higher than it recommends.

Air quality was poorest in Asia, followed by South America and Africa.

Air pollution linked to seven million deaths globally

Seven million people died as a result of air pollution in 2012, the World Health Organization estimates.

Its findings suggest a link between air pollution and heart disease, respiratory problems and cancer. One in eight global deaths were linked with air pollution, making it "the world's largest single environmental health risk", the WHO said.

Nearly six million of the deaths had been in South East Asia and the WHO's Western Pacific region, it found. The evidence signals the need for concerted action to clean up the air we all breathe”