North Korea said Sunday it was considering postponing a planned long-range rocket launch originally set for between December 10 and 22, citing unspecified problems during preparations.

The Korean Committee for Space Technology said its scientists and engineers were "considering seriously the possibility of readjusting the launch period".

A U.N. conference passed a package of agreements on Saturday combating climate change and extended the life of the Kyoto Protocol, the only binding pact on curbing Earth-warming greenhouse gas emissions, its chairman said.

Agreement on the modalities of a Kyoto "second commitment period," which seeks to rein in climate change pending a new global pact due to enter into force in 2020, concluded 12 days of tough haggling in Doha.

One of Kenya's best known private game reserves in Kenya announced Friday a plan to fly unmanned surveillance drones to monitor and protect critically endangered rhinos from rampant poaching.

Ol Pejeta, a 90,000-acre non-profit private wildlife conservancy in central Kenya's Laikipia District, holds four of the world’s last remaining seven northern white rhinos.

Frustration grew Friday with the Qatari hosts of U.N. climate talks stuttering towards a close in Doha, for failing to instil a sense of urgency in negotiators preparing themselves for a long night.

As some delegates urged conference chairman Abdullah Bin Hamad al-Attiyah to take matters in hand, he quipped in a stock-taking session: "I am not in a rush. I am at home. My house is only 10 minutes driving distance so I'd love you to stay here more days."

Animal rights activists on Friday renewed calls for a Singapore casino complex to free dolphins it acquired for a marine park, threatening to campaign for a boycott if their demand is ignored.

The Animal Concerns Research & Education Society (ACRES) of Singapore claimed the bottlenose dolphins were "being housed in appalling conditions, in tiny barren swimming pools" at Resorts World Sentosa (RWS).

NASA, the agency that epitomized the "Right Stuff," seems lost in space and doesn't have a clear sense of where it is going, an independent panel of science and engineering experts said in a stinging report Wednesday.

The one place the White House wants to send astronauts — an asteroid — doesn't seem to be getting the engines firing at NASA, they said.

Two former top NASA officials unveiled plans Thursday to sell manned flights to the moon by the end of the decade, in an announcement 40 years after the last human set foot there.

Spaceflight, long the province of national governments, has moved toward increased commercialization in recent years, with private companies for the first time successfully launching rockets into orbit.

Scientists Friday warned of an alarming increase in the death rates of the largest living organisms on the planet, the giant, old trees that harbor and sustain countless birds and wildlife.

Research by universities in Australia and the United States, published in Science, said ecosystems worldwide were in danger of losing forever their largest and oldest trees unless there were policy changes to better protect them.

Two Mexican textile factories that supply clothing for global fashion brands such as Levi's are dumping toxic chemicals into the environment, Greenpeace said Wednesday.

The environmental group said it found hazardous chemicals in samples taken from waste water discharges at the two facilities, run by Mexico's Lavamex and Kaltex companies, which dye and wash denim textiles.

Mosquito control officials in the Florida Keys are waiting for the federal government to sign off on an experiment that would release hundreds of thousands of genetically modified mosquitoes to reduce the risk of dengue fever in the tourist town of Key West.

If approved by the Food and Drug Administration, it would be the first such experiment in the U.S. Some Key West residents worry, though, that not enough research has been done to determine the risks that releasing genetically modified mosquitoes might pose to the Keys' fragile ecosystem.