Scientists Wednesday announced an advance in the quest to solve the growing problem of antibiotic resistance, saying they had found a chink in the armor of bacteria cells.

A resilient class of germs called Gram-negative bacteria have an impermeable lipid-based outer membrane that defends the cell against the human immune system as well as antibiotics.

Four former heads of the U.S. Environmental Protection Agency who served under Republican presidents urged lawmakers Wednesday to stop bickering over whether climate change is real and start finding solutions.

Global warming is an increasingly polarizing issue in American politics, with most Republicans questioning the science behind it and most Democrats calling for stricter pollution limits.

Antarctic scientists warned Wednesday that a surge in tourists visiting the frozen continent was threatening its fragile environment and called for better protection.

Tourist numbers have exploded from less than 5,000 in 1990 to about 40,000 a year, according to industry figures, and most people go to the fragmented ice-free areas that make up less than one percent of Antarctica.

U.N. cultural agency UNESCO on Wednesday warned Australia that the Great Barrier Reef could be put on a list of endangered World Heritage Sites if more is not done to protect it.

UNESCO's annual World Heritage Committee gathering, which takes place this year in Doha, called on Australia to submit a report on its actions by February 1, 2015 or face the possibility of the reef being put on the "in danger" list.

The United States Tuesday unveiled "historic" steps to combat illegal fishing and proposed plans to create the world's largest marine sanctuary in a bid to help save the world's besieged oceans.

"We all know how fragile our planet can be," Obama said opening the second day of a landmark conference dubbed "Our Ocean" urging everyone to "redouble our efforts."

Living with sub-zero temperatures for several months a year, Estonians are no strangers to a little snow.

But residents of the Baltic nation were baffled on Tuesday when flurries of the white stuff fell in June for the first time in more than three decades.

Japan is set to offer India a carbon offset scheme that would see Tokyo's environmental technology used by the rising Asian giant to help reduce its emissions, a report said.

The scheme would see Japanese firms earn carbon credits in return for helping developing countries reduce their greenhouse gas emissions, the Nikkei newspaper said in its Monday evening edition, adding India was a likely early partner.

A moderate earthquake shook northwest Alaska on Monday, the fifth temblor of the same magnitude since April in an area with otherwise little activity, seismologists said.

The magnitude-5.7 quake struck at 4:01 a.m. Monday northeast of the village of Noatak, the Alaska Earthquake Center reported. As with other temblors in the earthquake swarm, the quake was felt in Noatak, an Inupiat Eskimo community of 560 people.

Great white sharks are likely rising in numbers off the coast of California and are not at risk of extinction despite some reports to the contrary, U.S. researchers said Monday.

The findings are good news for the ocean predator, suggesting that around 2,000 of them are swimming about in the Eastern North Pacific, not 219 as research released three years ago had indicated.

U.S. Secretary of State John Kerry Monday sounded the alarm on the perils facing the world's oceans, calling for a global strategy to save the planet's life-giving seas.

"Let's develop a plan" to combat over-fishing, climate change and pollution, Kerry urged as he opened a ground-breaking two-day conference of world leaders, scientists and industry captains.