“What nonsense! Does anybody realize that the polar bear population has increased from 5,000 in 1972 to 25,000 today! To be put on a threatened or endangered list, shouldn’t the numbers be declining???”

This, from blog reader Vince, was a recurring theme among the hundreds of responses to yesterday’s decision to list the polar bear as a threatened species under the U.S. Endangered Species Act.

I’d seen this number cited before, but I’d never seen any attribution as to its source. After some web research, conversations with polar bear researchers, and some help from a longtime journalist who specializes in animal/wildlife stories, here’s what we could find.

The number has some basis in fact, but is misleading: If polar bears have built in numbers since the 1970’s, it probably had a lot more to do with hunting bans than any aspect of global warming.

Polar Bear habitat covers five nations: The U.S. (Alaska), Russia, Canada, Denmark (Greenland), and Norway (the Spitsbergen and Jan Mayen Islands). Those five nations, along with the International Union for the Conservation of Nature, took a stab at guesstimating worldwide polar bear populations in the early 1970’s. For example, based on observer reports from Arctic villages, ships, and other sources, U.S. researchers came up with an estimate of 18,000 polar bears throughout the Arctic. The Canadian Wildlife Service set the number at 20,000. The Soviet Union submitted the low bid, estimating a worldwide population of 5,000 animals. In late 1973, the five polar bear nations signed the International Agreement on the Conservation of Polar Bears, and agreed to go with the lower Soviet estimates in order to wrap up a wildlife agreement that was unheard-of during the Cold War years.

Whichever of these estimates may have been closer to the real number is still unclear. It’s generally believed that polar bear populations did grow after the treaty was signed — but it had nothing to do with the Arctic climate: The Treaty also set restrictions on trophy hunting for the big bears — outlawing the then-common, controversial practice of hunting polar bears by helicopter. The U.S. had already banned all but some native subsistence hunting the previous year, through the US Marine Mammal Protection Act.

But there’s another revealing number from that year: Merritt Clifton, the editor of Animal People , dug through online newspaper archives and discovered this tidbit: Canada was the last Arctic nation to curtail large-scale hunting of polar bears. According to a 1973 United Press International story, Canada’s Northwest Territories allowed a quota of 422 bears to be killed that year.

So let’s do the math: If the 5,000 number were correct, they authorized the killing of nearly 10% of the world’s polar bear population — In just one part of Canada’s polar bear habitat, and in just one year. It’s very difficult to accept that a global population of only 5,000 could have sustained that rate of loss.

More recent polar bear research suggests that any growth in worldwide population has likely stopped, and that the bears themselves are generally thinner and give birth to fewer young. Here’s the key USGS paper on the bears’ status in the U.S. part of their habitat. The current estimates for global polar bear population is between 22,000 and 25,000 — numbers too big to risk any immediate extinction. But the overwhelming amount of research on polar bear health and future prospects says they’re in for a rough ride in the next fifty years.

One credentialed, dissenting scientist is Dr. Mitchell Taylor, a researcher who did much of his work on behalf of Canada’s Nunavut Territory. Taylor has acknowledged that climate change is impacting polar bears, but he does not see a great risk of collapse of the species. The recently-retired Taylor has researched bear populations in the Davis Strait, between Canada and Greenland. Taylor is due to publish his results later in the year, and in newspaper interviews, he has said that bears in the region are healthy in both size and number. Critics point out that Nunavut, Dr. Taylor’s longtime employers, have a huge stake in what remains of the legal polar bear trophy-hunting business, estimated to be a $2 million business for impoverished Nunavut communities. Yesterday’s US decision to declare the bears as “threatened” will dry up a longstanding loophole: U.S. trophy hunters were barred from killing bears in the U.S. (Alaska), but prior to the ruling, could still obtain permits to hunt polar bears in Canada and import the trophies.

-Peter Dykstra, Executive Producer, CNN Science Tech & Weather

U.S. Interior Secretary Dirk Kempthorne announced that the polar bear will receive protection as a “threatened” species under the U. S. Endangered Species Act. Conservation groups had petitioned the U.S. to give protection to the mammals — citing a rapid decline in Arctic sea ice, and U.S. government studies predicting a rapid decline for the bear population due to loss of habitat. The government was under federal court order to rule on the bears’ status by tomorrow.

CNN.com will have full details soon.

-Peter Dykstra, Executive Producer, CNN Science & Technology

A federal judge says enough is enough — no more delay.  The Interior Department now has just 16 days to issue a decision on whether to list the polar bear under the Endangered Species Act because of global warming.

 The government was supposed to announce that decision by January 9.  But the Fish and Wildlife Service said it needed another month to make the complex listing more easily understood.  However, that month came and went, and environmental groups sued, leading to yesterday’s court ruling.

U.S. District Judge Claudia Wilken agreed with the conservation groups — the Center for Biological Diversity, the Natural Resources Defense Council, and Greenpeace — that Interior missed the deadline.  And she disagreed with a government request for another delay, ordering a decision be announced by May 15.

Judge Wilken ruled that Interior has been violating the Endangered Species Act for four months by missing the Jan. 9 deadline, and said the government has not offered sufficient justification for that delay, much less further delay. Interior has said it needed until June 30 to finish a legal and policy review of the proposed listing.

Environmentalists say they think the government is delaying the decision to make it easier for oil companies to get offshore oil leases in the Chukchi Sea, prime polar bear habitat.

The Fish and Wildlife Service proposed the ESA listing in December of 2006 because climate change is shrinking polar bear habitat.  Some scientists predict summer sea ice in the Arctic will disappear by 2030.  A U.S. Geological Survey study estimated that polar bears in Alaska could disappear by 2050.

Diane Hawkins-Cox    Senior Producer  CNN Sci-Tech

Scientists from the U.S. Geological Survey predict that two thirds of the world’s polar bears will disappear in the next 50 years because of declines in Arctic sea ice.

But those dire findings don’t seem to be lighting any fires under those making decisions about how to protect the majestic animals. The U.S. Fish and Wildlife Service was required to finalize its decision to list the polar bear as a threatened species by January 9 of this year.

As CNN reported earlier this week, Fish and Wildlife Director Dale Hall admitted his agency had missed the deadline, in an effort he said, to be thorough. That was January 17.
Now the Senate Committee on Environment and Public Works wants some answers.
Senator Barbara Boxer, (D-CA) who chairs that committee, is requesting that Secretary of the Interior Dirk Kempthorne (Hall’s boss) appear at a hearing next month to answer questions about the continued delay.

“It is time for the Interior Secretary to answer questions about the administration’s continued foot-dragging on the polar bear listing. Secretary Kempthorne must explain to the American people why his department has failed to follow the law and why they still haven’t issued a final decision to protect the polar bear,” Boxer said in a statement from the committee.

Will Kempthorne show up? In an e-mail, his press secretary told CNN: “The Secretary has a great deal of respect for Senator Boxer. We will respond to the Senator’s request in a timely manner.”

Perhaps complicating polar bear habitat issues, Interior officials have moved forward on approval of $2.7 billion in oil and gas leases in the Chukchi Sea. That area between Alaska and Siberia is home to about twenty percent of the planet’s polar bears.

–Marsha Walton, Producer, CNN Science and Technology

The giant panda may be beloved for its wide-eyed cuteness, but a slew of mysteries lie beneath its furry surface. Scientists at the Beijing Genomics Institute at Shenzhen will explore the genetic underpinnings of this endangered species through the newly-announced International Giant Panda Genome Project.

The genome project could provide important information for panda conservation, and contribute to the protection and monitoring of this rare creature. There are only about 1,600 giant pandas alive today, and their reproductive rate is low, says the San Diego Zoo. What’s more, humans invading panda habitats may create bamboo shortages or render the pandas homeless entirely. Pandas also fall into hunting traps.

Sequencing the giant panda’s genome will help scientists better understand pandas in the present and the past, the genomics institute says in its announcement. The results of the project could help determine how big the giant panda population has been historically, to what extent these creatures currently inbreed, and other unsolved panda questions.

The giant panda’s genome is about the same size as yours, and is thought to have between 20,000 and 30,000 genes, BGI-Shenzhen says. Though there has been speculation over the giant panda’s relationship to raccoons, genetic research has revealed that pandas belong to the bear family.

Besides being the subject of this study, the giant panda is a mascot for the 2008 Olympic Games in Beijing. The animal is also a hit on YouTube — this video of a baby panda sneezing has received more than 8 million views.

–Elizabeth Landau, Associate Producer, CNN.com

Of all the issues on Earth, the values of clean air and a healthy environment aren’t where you would expect to find a broken government and political gridlock.

Concerns about global warming, endangered species, energy and water supplies are mounting and many see the environment as the staging ground for a great train wreck between science, politics, money and ideology.

CNN’s “Broken Government: Scorched Earth,” examines tangled policies and ambitions and finds that the federal government has often stood in the way of environmental solutions. And, in some cases, well-intended programs have made problems worse rather than better.

In the Badlands of South Dakota, rancher Marv Jobgen is less than thrilled to share his federally-subsidized grazing land with prairie dogs, which are competing with his cattle to graze on grass. One federal agency hopes to expand a prairie dog poisoning program — on the same land where a rival federal agency is working to save the prairie dog.

The rodents may be competition for Jobgen’s cattle, but they’re dinner for the highly-endangered black-footed ferret. The ferrets are staging a government-backed comeback from the brink of extinction, but it all may be imperiled when the same government begins poisoning their food supply. Jobgen’s frustration is shared on all sides: environmentalists, government biologists who oversaw the ferret’s recovery, and ranchers.

“That’s what happens when you get agencies where nobody talks to anybody,” says Jobgen.

“Scorched Earth” also takes viewers to Iowa, the so-called “Kuwait of the Midwest,” where an estimated 30 percent of the nation’s corn crop is now grown — not for food — but for fuel. Corn is being touted as a “green” alternative and an antidote to America’s addiction to foreign oil.

But a backlash is building as some researchers find growing corn for fuel may actually cost more than it saves. Some experts have also blamed the corn crop for the explosive growth of the “Dead Zone” thousands of miles downstream at the mouth of the Mississippi River, where this nearly oxygen-free ocean area is wreaking havoc on the catches of Louisiana fisherman.

We also traveled to El Paso, Texas, where a century-old copper smelter stands amid a bleak landscape of lead pollution and health impacts, which some medical experts have linked to pollutants from the smelter.

Shuttered since the late ‘90s, when copper prices hit rock bottom, ASARCO recently got permission to reopen the plant. Even though ASARCO declared bankruptcy two years ago, citing “environmental liabilities” which may total $11 billion, the company recently received clearance to reopen. Some bankruptcy experts, local residents and city leaders are crying foul and say federal laws are protecting the company from paying cleanup costs.

- Miles O’Brien, CNN Science & Technology Correspondent

Watch “Broken Government: Scorched Earth” on Thursday, February 21, at 11 p.m. ET, immediately following the CNN Debate live in Austin, Texas.

Say the words “Tasmanian Devil” and for a lot of us, the edgy but lovable cartoon character “Taz” comes to mind.

Hammy, a healthy Tasmanian Devil, has the face of a bear, the size of a small dog, and a bone-chilling screech.
Photo courtesy: Dr. Hannah Bender

But the “real” devils, known for big teeth and loud screeches, are in grave danger of extinction from a deadly form of facial cancer.

Scientists are trying to make sure the snarky cartoon character isn’t the only image future generations have of the icon of Tasmania.

“It’s a very unusual mode of tumor transmission,” said Elizabeth Murchison, a native Tasmanian and molecular biologist at Cold Spring Harbor Laboratory (CSHL) in New York. A team of researchers at CSHL is studying Devil Face Tumor Disease, which was first identified in 1996.

This cancer spreads when one infected animal scratches or bites another, passing on the deadly cells. The tumors grow aggressively on the face and neck; eventually they become so large the animal cannot eat and dies of starvation.

On some parts of the island of Tasmania, south of Australia, more than 90% of the devil population has been wiped out.

Murchison and her colleagues are sequencing the genes in the devils’ tumors, to better understand the genetic makeup of this rapid cancer growth.

“Everyone in Tasmania is passionate about the animal, it is part of our identity,” said Murchison. “We have a big responsibility to keep it in its natural habitat.”

Australian veterinarian Hannah Bender, also working at Cold Spring Harbor Lab, is investigating why the cancer spreads so rapidly.

“One theory is that the population is incredibly inbred, “ she said. That means the devil’s immune system doesn’t recognize the cancer cells as foreign, and does nothing to try to fight them off.

“We have to look at this as a chance for modern molecular biology to help in an environmental catastrophe,” said Greg Hannon, Cold Spring Harbor Laboratory professor.

So future generations won’t only know this noisy nocturnal marsupial from pictures in a textbook.

(Full disclosure: “Taz” is a Warner Brothers creation; CNN is owned by Time Warner.)

The Tasmanian Government and the University of Tasmania are working to save the Tasmanian Devil. Find out more here.

Click here to hear the bone-chilling screech of the Tasmanian devil. Its howl could also speak for more than 5000 endangered animal species worldwide.

Marsha Walton, Producer, CNN Sci-Tech