The US government is pushing forward with controversial plans to allow drilling in the Arctic National Wildlife Refuge, by laying out the terms of a leasing programme that would give oil companies access to the area.

The wildlife refuge in north-eastern Alaska sits above billions of barrels of oil. However, it is also home to many animals, including reindeer, polar bears and different species of bird.

The idea of drilling in the area did not originate with President Donald Trump and his administration. Rather, the leasing programme is just the latest step in a controversy that has been ongoing since the late 1970s.

One side argues that drilling for oil could bring in significant amounts of money, while providing jobs for people in Alaska.

Others, however, are fearful of the impact drilling would have on the many animals that live there - as well as the damage burning more fossil fuels would have on our rapidly warming planet.

This push from the Trump administration comes just two months after the Arctic circle recorded its highest ever temperatures.

"This plan could devastate the amazing array of wildlife that call the refuge home through noise pollution, habitat destruction, oil spills, and more climate chaos," Kristen Monsell, from the US-based Center for Biological Diversity, told the BBC.

"The coastal plain is the most important land-based denning habitat for polar bears and is the birthing grounds of the Porcupine caribou herd.

"Over 200 species of birds are found in the refuge along with Arctic foxes, black and brown bears, moose and many others."

Any oil spills, for example, would not only harm nearby wildlife and their habitat, they could be fatal.

Polar bears, Ms Monsell adds, are "particularly vulnerable" to oil spills.

"Polar bears must maintain a pristine hair coat as insulation against the cold - but when a polar bear comes into contact with spilled oil, it can soak a polar bear’s fur and persist for several weeks. It will be groomed and ingested, irritate the skin, and destroy the insulating abilities of the fur," she says.

"Studies show that fatalities can occur from effects on the lungs, kidneys, blood, gastrointestinal tract, and other organs and systems. An oil-coated bear that is not cleaned and rehabilitated will probably die."

Oil industry bosses insist they have a well-established record of environmentally responsible development of Alaska’s energy resources. But environmentalists say the US government has not adequately considered the risks to wildlife and local communities.

Meanwhile, polar bears are far from the only animals who rely on this large stretch of wilderness.

The refuge is home to more than 200 types of bird. Prof Natalie Boelman, an environmental scientist from Columbia University, describes it as "a huge nursery for avian species".

"If you go up there in the spring it’s crazy, every little puddle, even if it’s just half a metre by half a metre… you can barely see the water, it’s just covered in ducks and geese," she tells the BBC.

She is particularly concerned about the impact sound levels from any drilling would have on animals in the refuge, as well as on the indigenous communities that live nearby.

"With industrial activity comes a great deal of sound, from aeroplane noise, helicopter noise, truck noises, seismic activity," she says.

"There’s been very little scientific study into how this impacts the many different animals up there, but there’s a lot of anecdotal evidence that sounds that are associated with any anthropogenic activity really bother them."

This anecdotal evidence, she adds, comes from the Native Alaskan communities that live near the refuge.

"Subsistence hunters who are really dependent on both caribou and waterfowl to sustain themselves and their families, they have a really hard time hunting when there’s air traffic going by," Prof Boelman says.

"They report having to just give up hunting a specific animal as soon as a helicopter or aeroplane goes by, because it just wakes the animal up - and that’s a huge loss for them.

"So we know it has an impact on the behaviour of the animals, and also that this then has an effect on the subsistence of communities. But also, what does that noise do to animals’ stress levels? What does that do to their reproductive success?"

Conservationists also fear for the Porcupine caribou, a breed of North American reindeer which roams the Arctic National Wildlife Refuge. The coast - where proposed drilling would take place, should it go ahead - is particularly important to them.

Maggie Howell, executive director of the Wolf Conservation Center, tells the BBC: "That coastal plain is the calving route for caribou, and the caribou also has one of the most impressive migrations of any land mammal.

"The herd travels north to the coastal plain every year, about 400 miles (644km) each way, and that’s where they’re having their babies. Any drilling is going to impact their lives drastically, as well as all the other animals and people who depend on that caribou."

One animal that predates on caribou, and would therefore also be at risk, is the Alaskan tundra wolf. Ms Howell says her team has "already seen" the damage done by drilling in other areas with caribou and wolf populations, such as Alberta in Canada.

"As a refuge, it’s there to be preserved," Ms Howell says. "It’s not only a safe haven for the wildlife, but also a symbol of our country’s national heritage.

"And if these animals can’t be safe in a wildlife refuge, where can they be? Where can they be just left alone to live their lives and fulfil their own purpose?"