"On a cool December night in Paris, at an awards ceremony in the city’s 3rd arrondissement, Eduardo Paes, the mayor of Rio de Janeiro, took the stage to thunderous applause from an audience full of his fellow mayors from around the world. Paes’ voiced boomed as he stressed the importance of cities leading the fight against climate change ...."

"Rio de Janeiro's air is dirtier and deadlier than portrayed by authorities and the Olympics' promised legacy of cleaner winds has not remotely been met, an analysis of government data and Reuters' own testing found."

"A major part of Rio’s winning Olympic bid was a plan to capture and treat 80 percent of the sewage that flows into Guanabara Bay, something organizers now admit will not happen — certainly not by August, if ever."

"How the country challenged the junk-food industry and became a global leader in the battle against obesity."

"The fate of a mysterious hummingbird — and that of the indigenous population that shares its territory — hangs by a thread."

"A new pollution problem has surfaced in Guanabara Bay, the venue for sailing in the Rio de Janeiro Olympics."

"SANTIAGO - A ban on harvesting shellfish in Chiloé due to a severe red tide outbreak sparked a social uprising that has partially isolated thousands of local residents of the southern Chilean archipelago and revived criticism of an export model that condemns small-scale fishing communities to poverty and marginalisation."

"Federal prosecutors in Brazil filed a 155 billion-real ($43.5 billion) civil lawsuit on Tuesday against iron miner Samarco and its owners, Vale SA and BHP Billiton, for a collapsed tailings dam in November that killed 19 people and polluted a major river."

"After sampling muddy water from the mouth of the Amazon River, oceanographer Patricia Yager steamed in the research ship Atlantis toward the continental shelf, where a Brazilian colleague was chasing a phantom. Yager’s colleague was carrying a 1977 six-page research paper that included a hand-drawn map suggesting this region might mask an extraordinary set of reefs."

"Four men have been found guilty in Costa Rica for the killing of a sea turtle conservationist in 2013. The chief of a three-judge panel said the slaying of Jairo Mora Sandoval, who worked for a green group called Widecast, was tied to his activism in a war 'between poachers and environmentalists on the beach.'"