Thin Polar Bears Called Sign of Global Warming

Environmental News Service ^ | 05/16/2002

[cogitator]

Thin Polar Bears Called Sign of Global Warming

WASHINGTON, DC, May 16, 2002 (ENS) - Hungry polar bears are one of the early signs that global warming is impacting Arctic habitat, suggests a new study from World Wildlife Fund. The report reviews the threats faced by the world's 22,000 polar bears and highlights growing evidence that human induced climate change is the number one long term threat to the survival of the world's largest land based carnivores.

Global warming threatens to destroy critical polar bear habitat, charges the report, "Polar Bears at Risk." The burning of coal and other fuels emits carbon dioxide (CO2) and other gases that blanket the earth, trap in heat and cause global warming.

According to the Intergovernmental Panel on Climate Change (IPCC), climate change in the polar region is expected to be the greatest of anywhere on Earth.

"The WWF report shows that polar bears in Hudson Bay are being impacted by climate change," said Lynn Rosentrater, coauthor of the report and climate scientist at the World Wildlife Fund's (WWF) Arctic program. "The polar bear's basis for survival is being threatened by the reduction of the sea ice."

"Since the sea ice is melting earlier in the spring, polar bears move to land earlier without having developed as much fat reserves to survive the ice free season," Rosentrater explained. "They are skinny bears by the end of summer, which in the worst case can affect their ability to reproduce."

Increasing CO2 emissions have caused Arctic temperatures to rise by five degrees Celsius over the past 100 years, and the extent of sea ice has decreased by six percent over the past 20 years. By around 2050, scientists now predict a 60 percent loss of summer sea ice, which would more than double the summer ice free season from 60 to 150 days.

Sea ice is critical to polar bears' survival because it is the platform from where they hunt their primary prey - ringed seals and bearded seals. Diminishing ice cover and longer ice free periods limit the time the bears have on the ice to hunt and means that they have fewer fat resources to survive during the longer summer season.

Lower body weight also reduces female bears' ability to lactate, leading to fewer surviving cubs. Already, fewer than 44 percent of cubs now survive the ice free season.

As early as 1999, Canadian researchers noticed that polar bears in the Hudson Bay region were having trouble finding enough seals to eat due to the earlier breakup of sea ice. The scientists from the Canadian Wildlife Service found that weight for both male and female polar bears was declining, and female bears were having fewer cubs.

The impacts of global warming come on top of problems that polar bears already face from hunting, toxic pollution and oil development in the Arctic. The Arctic region is contaminated by pesticides and other chemicals carried by air and condensation from industrialized areas far to the south.

The pollutants enter the food chain, and animals at the top of the chain, such as polar bears, can carry tremendous body burdens of toxic chemicals. Research on polar bears has shown a link between high contaminant levels and reduced immune system function.

Due to the rapid pace of change in the Arctic, there is no time to lose in reducing emissions of greenhouse gases, WWF argues. The group says major reductions can be achieved by using existing technologies to increase the energy efficiency of homes, businesses and automobiles, and by using renewable energy sources instead of fossil fuels.

Bipartisan support has grown in Congress for a renewable portfolio standard that would ensure that 20 percent of U.S. energy comes from renewable energy by 2020. However, President George W. Bush has opposed the proposal.

World leaders will discuss a similar proposal at the World Summit for Sustainable Development in South Africa this summer. The WWF is calling on President Bush to support this initiative in Johannesburg.

"Arctic nations that are home to most of the world's polar bears should be leading the charge against global warming," said Jennifer Morgan, director of WWF's climate change program. "Instead, the United States - the world's largest global warming polluter - is essentially ignoring this problem. All eyes will be on President Bush at the upcoming World Summit on Sustainable Development in South Africa this August to test his commitment to sustainable energy solutions for climate change."

The WWF has created a new Web site: http://www.panda.org/polarbears with extensive information about polar bears and their Arctic domain. The site includes satellite tracking of two female bears, Louise and Gro, as they roam the ice pack in search of prey.

[cogitator]

Isn't this good news for the seals? I thought the WWF was also concerned with the seal population.

Depends on the seal. I don't know if any of the Arctic seal populations are significantly endangered. The only one that I can think of that is showing a significant decline is the Steller's sea lion, and that's probably due to alteration in fish availability in the Bering Sea and north Pacific Ocean. (And I remember reading that the decline in the Steller's sea lion, a favorite orca repast, is causing orcas to target smaller morsels, like sea otters.)

[cogitator]

One wonders what the bears did during the several hundred years medieval warming period.

Excellent question. Polar bear populations probably moved north during that period.

[cinFLA]

Increasing CO2 emissions have caused Arctic temperatures to rise by five degrees Celsius over the past 100 years

Increasing temperatures have caused increased CO2 concentrations.

[redhead]

"Hungry polar bears are one of the early signs that global warming is impacting Arctic habitat, suggests a new study from World Wildlife Fund."

Now, let's see...early spring...bears emerging from hibernation...fat stores used up...Naw. Couldn't be.

[redhead]

"The United States isn't exactly an "Arctic" nation..."

One word: ALASKA

Last time I looked, Alaska was still part of the United States.

[aShepard]

Maybe the eskimos have been putting lids on their garbage cans, and fences around their dumps to keep the bears out of town.

Poor guys can't scavage anymore

[cogitator]

It's good to have you back, JasonC.

The Global Warming Debate (PDF)

Comment on Slide 7, page 12.

[Always Right]

I'd suggest proposing 15 indicators that have a defined trend over 1992-2002. I'd predict that by 2012 a majority (8) of these indicators will have a more pronounced trend in the same direction as current.

I would propose 2, if either one happens you win. The IPCC predicts about a 4-10 degree F rise in temps over the next 100 years. I would say lets place the limit at 0.5 degree F rise over the next 10 years as measured by US thermometer data. The IPCC is predicting a 5mm rise per year in sea levels. That's about 2.5 inches over 10 years, not sure who I trust on this one, but I am sure we can agree on someone.

[the bottle let me down]

I would think that thin polar bears means LONGER winters. A polar bear could eat more and obtain more fat in warmer climates............

Polar bears hunt most often and successfully on ice. The white color is camoflage, after all. Colder temps mean more ice and a longer season fo rthe bears to hunt and eat.

[nhbob1]

Maybe the morons who wrote the article don't know the difference between 5 and 0.5 C (which is about the reported average temp increase over the last century, and some people even question that).

[willyone]

If historical records are to be believed for four hundred years the Vikings lived in Greenland and actually prospered. It was originally called Vineland because the mild climate enabled grapes to be grown. Then the climate turned cold and they had to abandon Greenland. So what did Polar Bears do during that warming phase? Phone for takeout? Anyone who has been to the Exit Glacier near Seward will have seen the signs which start miles away showing where the glacier was at different dates. Two hundred years ago it was six miles away. Was there global warming caused by cars two hundred years ago? Not likely.

[cogitator]

I would propose 2, if either one happens you win. The IPCC predicts about a 4-10 degree F rise in temps over the next 100 years. I would say lets place the limit at 0.5 degree F rise over the next 10 years as measured by US thermometer data. The IPCC is predicting a 5mm rise per year in sea levels. That's about 2.5 inches over 10 years, not sure who I trust on this one, but I am sure we can agree on someone.

You gotta remember, I'm not advocating worst-case IPCC scenarios. I think we're going to see a ~2.5 C rise in global temperature in the next CENTURY. Which (if linear, which it won't be) would be 0.25 C in 10 years. That's 0.4 F in 10 years. So if you'd be willing to bet on a 0.3 F (0.18 C) degree rise in global temperature as determined by the National Climatic Data Center over the next decade, I'd take it (for a 12-pack of Blue Ridge Amber Lager, not for $10K). And I win if for any year the yearly global average temperature is 0.18 C higher than the yearly global average temperature for 2002. This year could have a moderate El Nino in it, so that's not a bad starting point.

I don't trust anybody's sea-level rise data. The difference between U.S. analysis of TOPEX/Poseidon altimetry data and European analysis of the same data is different by like 5 mm. So here's an alternative: the timing of spring thaw on northern lakes and rivers will be earlier, on average, by more than 1 day over the period 2002-2012. We will consult Dr. John Magnuson of the University of Wisconsin or whoever inherits his data set should he become unavailable.

[MamaTexan]

I would love to see the fat vs. body mass stats kept during the last 100 years.

Didn't the government just change the body mass / fat ratio statistics and make 3 million Americans instantly overweight?

I wonder if they have one for polar bears. :)

[born yesterday]

I value your analysis. One thing more.

According to review article in CO2science.com on Ice Ages: From studies of climate over 2,000,000 years, Interglacials consistently last 10,000 years. But our current Interglacial began 11,500 years ago. We're overdue for another Ice Age.

We're worrying about the wrong thing.

[Always Right]

Actually, I wasn't using the worst case IPCC numbers, but their best case numbers (which are really worst-worst case numbers). But anyways the 0.3F degree rise is probably a reasonable place to set the mark. Here is NCDC data for the US:

I don't think a single year would work very well as the yearly values vary too greatly and it would be very likely one year would be higher. We could set the starting point at 54.2F for 2001 and if the data for 2002-2012 produce a best fit line with a tempreture greater than 54.5F in 2012, you win.

[cogitator]

I don't think a single year would work very well as the yearly values vary too greatly and it would be very likely one year would be higher. We could set the starting point at 54.2F for 2001 and if the data for 2002-2012 produce a best fit line with a tempreture greater than 54.5F in 2012, you win.

I'll consider over the weekend. What about the spring thaw criterion?

[redhead]

"Maybe the eskimos have been putting lids on their garbage cans, and fences around their dumps to keep the bears out of town. Poor guys can't scavage anymore."

We used to put newspapers on top of the garbage and soak it with ammonia. It was SUPPOSED to keep the bears away. All they did then was knock the cans over. It didn't stop them from coming into the yards and tearing up gardens and trying to eat pets.

[Ditter]

We wondered the same thing when we went to see the Fox Glacier in New Zealand. A sign on the road told where the glacier was in 1750 & then up the road about 1/4 mile was another sign that said the glacier was here in 1850 & in another 1/4 mile (aprox.) you saw the glacier. What caused the global warming that melted the glacier from 1750 until the 20th century? Could it be.................... nature? Nah, it was the Maories.

[Ditter]

Polar bears don't hibernate in the winter like the other kinds of bears?

[Ditter]

I'm confused. In northern climes, I have seen plenty of seals when there wasn't any ice. Also other kinds of bears hibernate in the winter, when they come out of hibernation in the late spring, they are very thin. You are saying that polar bears do the opposite?