A man wades in the sea at Ipanema Beach during sunset in Rio de Janeiro June 4, 2014. Rio de Janeiro, with its white beaches, blue ocean and jungle-covered mountains, is still the place that comes to mind when people think of Brazil. Soccer fans coming to
A man wades in the sea at Ipanema Beach during sunset in Rio de Janeiro June 4, 2014. Rio de Janeiro, with its white beaches, blue ocean and jungle-covered mountains, is still the place that comes to mind when people think of Brazil. Soccer fans coming to Rio for the World Cup will be too late for the city's famed Carnival bash, but they'll also miss the energy-sapping Southern Hemisphere summer heat. By all means visit tourist favorites such as Pao de Acucar (Sugar Loaf Mountain) and the Christ the Redeemer statue on Corcovado, but here are places that locals enjoy, too. Despite its party reputation, Rio is also a daytime city. Obsessed with health and good looks, many Cariocas, as the locals are known, work hard to keep tan and fit. The beach is best at late morning and late afternoon. The most popular spots are between Posto 7 and Posto 10 in Ipanema.Each posto is a lifeguard station whose number serves as a beach address. Picture taken on June 4, 2014. To match story TRAVEL-RIO/ REUTERS/Sergio Moraes (BRAZIL - Tags: SPORT SOCCER WORLD CUP TRAVEL SOCIETY)
A man wades in the sea at Ipanema Beach during sunset in Rio de Janeiro June 4, 2014. Rio de Janeiro, with its white beaches, blue ocean and jungle-covered mountains, is still the place that comes to mind when people think of Brazil. Soccer fans coming to Rio for the World Cup will be too late for the city's famed Carnival bash, but they'll also miss the energy-sapping Southern Hemisphere summer heat. By all means visit tourist favorites such as Pao de Acucar (Sugar Loaf Mountain) and the Christ the Redeemer statue on Corcovado, but here are places that locals enjoy, too. Despite its party reputation, Rio is also a daytime city. Obsessed with health and good looks, many Cariocas, as the locals are known, work hard to keep tan and fit. The beach is best at late morning and late afternoon. The most popular spots are between Posto 7 and Posto 10 in Ipanema.Each posto is a lifeguard station whose number serves as a beach address. Picture taken on June 4, 2014. To match story TRAVEL-RIO/ REUTERS/Sergio Moraes (BRAZIL - Tags: SPORT SOCCER WORLD CUP TRAVEL SOCIETY)

A U.N. report released on Thursday said the continuing rise in the average temperature of the Earth's climate system is posing irreversible damages to the coral reefs in the world's smaller islands.

The study by the United Nations' Environment Programme (UNEP) said coral reefs found along the Indian Ocean to the Caribbean are at risk of the warming waters which kill the tiny animals that form corals with their stony skeletons.

Of all the ecosystems on Earth, the "corals .. are probably the most threatened," Robert Costanza, of the Australian National University and lead author of the study, told Reuters.

"These 52 nations, home to over 62 million people, emit less than one per cent of global greenhouse gases, yet they suffer disproportionately from the climate change that global emissions cause," Achim Steiner, head of UNEP.

"Some islands could become uninhabitable and others are faced with the potential loss of their entire territories," the study said. Corals help protect coasts from storms and tsunamis. They are also vital to attract tourists. Moreover, corals serve as nurseries for many types of fish.

The warming temperatures have spurred seawaters to rise. The effect ultimately bleached corals, depleted fisheries and pushed salt water onto farmland, Bloomberg said.

UNEP disclosed that in some parts of the Caribbean, all the reefs have been bleached.

The loss of corals is threatening the livelihood and existence of the people in the islands.

"Our fishermen are reporting less and less catches in areas where there was once a thriving trade," Reuters quoted Grenada's Environment Minister Roland Bhola said on the sidelines on the occasion of the U.N.'s World Environment Day on June 5 in the western German city of Bonn.

"We have been able to associate that with the issues of climate change ... the destruction of our coral reefs and other ecosystems like mangroves," he said.