RIO DE JANEIRO – Hollywood heavyweights threw their star power behind environmental causes on Thursday, advocating for the creation of an Arctic reserve and the protection of animal and plant species.

Actor Edward Norton, the United Nations goodwill ambassador for biodiversity, appeared at a news conference at the U.N.’s Rio+20 earth summit to raise awareness of the fight to preserve the planet’s rich variety of species at a time when flora and fauna are going extinct at an alarming rate.

“Loss of biodiversity is a very difficult form of environmental degradation for people to wrap their minds around,” the “Fight Club” star told participants at the news conference, held on day two of the United Nations’ Rio+20 earth summit. “They don’t see species disappearing in front of them in a short time-frame. They don’t necessarily see and feel every day their reliance on biodiversity.”

He said people often don’t realize how biodiversity touches their daily lives, from the bees and other insects and birds that pollinate the fruits we eat to the predators that keep other species in check. Norton added that it was his role as goodwill ambassador to highlight to what extent human survival is linked to that of the planet’s other animals and plants.

“You can’t protect something that people don’t value. So we have to work to make sure that people value biodiversity and see how it has value in their own lives,” he said.

Robert Redford, Penelope Cruz and former Beatle Paul McCartney were among a host of other A-listers to sign Greenpeace’s petition for the creation of a global sanctuary around the North Pole, with a ban on offshore oil drilling and an end to unsustainable fishing.

The environmental group said the North Pole should have the same sorts of protections given the Antarctic more than 20 years ago. No single nation has sovereignty over Antarctica, and the continent is reserved for scientific research, off-limits to commercial projects.

The Arctic, which is believed to hold up to a quarter of the Earth’s undiscovered oil and gas, is currently considered the high seas, but several nations have recently made plays to establish their sovereignty over the Arctic seabed, a move that could open the area to deep-sea oil drilling.

Russia, the United States, Canada, Denmark and Norway have all been trying to assert jurisdiction over parts of the Arctic. In 2007, Russia staked a symbolic claim to the region by dropping a canister containing the Russian flag on the ocean floor from a small submarine at the North Pole.

Greenpeace’s campaign plays off the Russian move. The group said that after 1 million people sign the petition, it plans to plant the document on the Arctic seabed, some 4 kilometres (2.5 miles) beneath the ice.

Greenpeace executive director Kumi Naidoo was quoted in a statement as saying, “The Arctic is coming under assault” and urging public support for the campaign.

“A ban on offshore oil drilling and unsustainable fishing would be a huge victory against the forces ranged against this precious region,” he said. “And a sanctuary in the uninhabited area around the pole would in a stroke stop the polluters colonizing the top of the world.”