The Summer Olympics which begins Friday, July 27, 2012, in London proudly aims to be the greenest Olympics ever. It's a lofty goal. But critics challenge whether it will succeed, or whether any Olympics can avoid negative environmental impacts.

Researchers are studying whether the chytrid fungus -- which has decimated frog and salamander populations around the world -- is being spread among wild amphibians by the release of infected animals bought at pet stores. The fungus has devastated some 200 species globally, and may be responsible for the greatest known disease-caused loss of biodiversity in recorded history.

"A government-appointed inquiry into Japan's Fukushima nuclear crisis raised doubts on Monday about whether other atomic plants were prepared for massive disasters despite new safety rules, and delivered a damning assessment of the regulators and the station's operator."

"WASHINGTON — With the growing conviction that the Assad family’s 42-year grip on power in Syria is coming to an end, Obama administration officials worked on contingency plans Wednesday for a collapse of the Syrian government, focusing particularly on the chemical weapons that Syria is thought to possess and that President Bashar al-Assad could try to use on opposition forces and civilians."

"Norfolk police close case and confirm the hack came from 'sophisticated' outsiders – not a University of East Anglia leak."

"Japan will on Wednesday restart its second nuclear reactor after the Fukushima crisis closed the nation's atomic power plants, even as fresh concerns surfaced about the unit's positioning near a faultline."

"A chunk of ice twice the size of Manhattan has parted from Greenland’s Petermann glacier, a break researchers at the University of Delaware and Canadian Ice Service attributed to warmer ocean temperatures."

"There’s a term biologists and economists use these days -- ecosystem services -- which refers to the many ways nature supports the human endeavor. Forests filter the water we drink, for example, and birds and bees pollinate crops, both of which have substantial economic as well as biological value."

"Senior environment officials from the United States, Mexico and Canada meeting in New Orleans on Wednesday were briefed on environmental concerns facing homeland communities, including indoor air pollution in Alaska, protecting freshwater sources from sewage and other pollutants in Mexico, and the impact of climate change already on First Nation villages along the Arctic Circle."

"For salmon trying to make it upriver to spawn before a hot summer hits, slow and steady loses the evolutionary race. Salmon DNA records stretching back over 30 years show that nature has increasingly selected for fish that migrate from the ocean earlier in the year. It is among the first pieces of genetic evidence that climate change is driving the evolution of a species."