Environmental pressure group Greenpeace accused pipeline firm TransCanada of "dirty tricks" Tuesday, publishing leaked documents it said showed it plans to smear opponents of one of its projects.

TransCanada, the company behind the controversial Keystone XL pipeline to take oil to the United States, also plans to connect Alberta's oil sands to refineries and ports in eastern Canada.

A once-in-a-decade global forum on parks closed in Sydney on Wednesday calling for an urgent increase in ocean protection and stressing the economic benefits of natural sanctuaries.

The World Parks Congress, with representatives from 160 nations, outlined a pathway for achieving a global target to protect at least 17 percent of land and 10 percent of oceans by 2020.

Chinese scientists are planning to launch a Mars rover "around 2020", state media reported Tuesday, as the country pours billions into its space program and works to catch up with the U.S. and Europe.

Although the government has not officially announced plans for a Mars mission, officials from the China National Space Administration are currently lobbying to have it put on the agenda and have begun "preliminary research", the state-run China Daily reported.

Japan said Tuesday it has cut its Antarctic whale-catch quota by two-thirds in a move it hopes will convince international opponents it is conducting real science, not hiding a commercial hunt behind a veneer of research.

The International Court of Justice -- the highest court of the United Nations -- ruled in March that Japan was abusing a scientific exemption set out in the 1986 moratorium on whaling.

The smell of money hangs thick in the air as black crude oil bubbles up from what is billed as the world's oldest oil well, but this is not Texas or Saudi Arabia.

The sleepy village of Bobrka in southern Poland lays claim to the planet's first oil well and rig, one that is still pumping up enough black gold to be profitable.

The European Space Agency (ESA)on Sunday unveiled images of the probe Philae after it bounced while making its historic landing on a comet last Wednesday.

The discovery came thanks to painstaking follow-up analysis of a series of pictures ESA had released on Friday, the agency said.

The Pacific bluefin tuna, a fish used in sushi and sashimi dishes, is at risk of extinction as the global food market places "unsustainable pressure" on the species and others, a conservation body warned Monday.

The bluefin tuna joined the Chinese pufferfish, American eel, Chinese cobra and Australian black grass-dart butterfly on the International Union for Conservation of Nature's (IUCN) "red list" of threatened species.

Leaders of the world's most powerful economies on Sunday backed "strong and effective action" on climate change while throwing their support behind the U.N.'s Green Climate Fund, aimed at helping poorer countries deal with the problem.

"We support strong and effective action to address climate change," G20 leaders said in a communique after weekend talks in Brisbane.

A huge whale was stranded Friday on a white sand beach on Nicaragua's southern Pacific coast, despite efforts by dozens of tourists and residents to get it back to sea.

The whale, estimated at 18 meters (59 feet) long, beached itself Friday morning at Popoyo beach, in the town of Tola, some 111 kilometers (70 miles) south of the capital, according to the Environment Ministry's delegate in the region, Mario Rodriguez.

A Sino-U.S. breakthrough on curbing carbon emissions proves a global deal on climate change is achievable, U.S. President Barack Obama said Saturday, as campaigners hailed new momentum in long-stalled talks.

Announcing a $3 billion contribution to a U.N.-backed climate change mitigation fund, Obama said the China-U.S. deal unveiled earlier this week showed the way forward.