Allergy season is extending, scientists find

Bad news for those who suffer their way through ragweed season: A team of researchers has found that increased warming, particularly in the northern half of North America, has added weeks to the fall pollen season. A changing climate means allergy-causing ragweed pollen has not only a longer season but one that extends further north than it did just 16 years ago.

In research that gibes with projections by the U.N. Intergovernmental Panel on Climate Change, plant and allergy experts found that ragweed pollen season lasted as much as 27 days longer in 2009 than it did in 1995. The further north in the Western Hemisphere, the more dramatic the change in the length of pollen season.

Minneapolis has tacked 16 days to the ragweed pollen season since 1995; LaCrosse, Wisc. has added 13 days, Winnipeg and Saskatoon in Canada have added 25 and 27 days, respectively.

The new research, published Monday in the journal Proceedings of the National Academy of Sciences, finds the longer pollen seasons correlate with the disproportionate warming happening around the planet and attributed to greenhouse gas emissions.

Upper latitudes are warming faster than mid-latitudes, and the pollen season is lengthening in proportion. Scientists and health officials found no appreciable warming in Texas, Arkansas or Oklahoma.

The impact goes far beyond mere sniffles and inconvenience. Some 50 million Americans have allergies, according to the Asthma and Allergy Foundation of America. Of those, 35 million suffer nasal allergies, known broadly as hay fever, said Mike Tringale, the association's vice president.

For 75 percent of those 35 million, ragweed (right) is the primary allergen, he added. And in many cases, allergies can trigger a bout of asthma, or make it worse.

Ragweed pollen can cause asthma flare-ups and hay fever, and costs about $21 billion a year in the United States, according to the study published in the Proceedings of the National Academy of Sciences.

"This is not something that's hypothesized, this is not something that's modeled, this is not something that may or may not occur depending on the math that you do," said study author Lewis Ziska of the U.S. Department of Agriculture crop system and global change laboratory. "This is something that we're actually seeing on the ground in recent years."

Even in places where ragweed season didn't lengthen or even shortened slightly -- such as Texas, Oklahoma and Arkansas -- there was lots more pollen, which caused more intense symptoms, said co-author Dr. Jay Portnoy of the Allergy, Asthma and Immunology Section at Children's Mercy Hospital, the University of Missouri-Kansas City School of Medicine.

Ragweed is probably not the only pollen likely to have a longer season as the planet warms, Portnoy said in a telephone interview.

"We used ragweed as a marker but it's probably true for other pollens too," he said, including tree pollen that causes allergy symptoms in the U.S. spring. (Right: pollen seasons. click to see enlarged image)

Ragweed pollen was a reasonable marker because its season is naturally easy to track.

It's what's known as a short-day plant, which begins blooming when the days start getting shorter, that is, after the Northern Hemisphere summer solstice around June 21. It stops flowering with the first frost.

As global average temperatures have warmed, the first frost has been delayed, especially at higher latitudes, which has meant a longer season for ragweed. Because warming is greater at these high latitudes, the length of the season has been more pronounced.

The findings correlate with analysis last year by the National Wildlife Federation that found ragweed growth rates and pollen counts increased with global warming. In one study, accelerating spring's arrival by 30 days prompted a 54 percent increase in ragweed pollen production.

The danger with a lengthening season - and perhaps a more intense one - is pollen's potential to overwhelm immune systems that, up till now, have withstood the onslaught, Tringale said.

Much as water in a bathtub is not a problem until it starts to overflow, pollen for many is not an irritant until it crosses a particular threshold, he said.

"With the longer season, with the creeping breadth of the geographic footprint of the season, and with more powerful plants producing more pollen, it's a triple threat," he added. "Now you've got yourself a much wider population that could potentially be affected that might not have been affected before.'

Source:
Daily Climate,"Allergy season is extending, scientists find",accessed February 21,2011
Reuters,"Climate change creates longer ragweed season", accessed February 21, 2011
Scientific American, "Climate Change Extends Allergy Season in North America", accessed February 21, 2011

Australia's floods a glimpse of warmer future

Though you can't make a direct link between Australia's killer floods and climate change, they do hold a warning for the future: Scientists predict such extreme weather events will increase both in intensity and frequency as the planet warms.

Raging floodwaters have swamped thousands of homes and businesses in Queensland, leaving at least 25 people dead and dozens more missing since late November. Rail lines and highways (right) have been washed away in what is shaping up to become Australia's costliest natural disaster.

The flooding follows a spate of severe natural disasters in the past year. While the most deadly was Haiti's earthquake, extreme weather also killed thousands of people across the globe, including a scorching heat wave that choked Russia in the summer and devastating floods that engulfed more than 60,000 square miles (150,000 square kilometers) in Pakistan.

"The Earth is delivering a message to us. And the message is that more extreme weather is becoming the norm rather than the exception," said John Magrath, a climate change researcher at British charity Oxfam.

He said there is a misconception that global warming only means higher temperatures. "It actually means more energy in the climatic system, which stimulates extremes and more chaotic behavior," Magrath said.

Droughts and floods are expected to become more severe as global temperatures climb. Less clear is the impact on wind patterns and ocean currents, factors that could alter climate in potentially dramatic ways not fully understood yet.

Last year tied with 2005 as the warmest on record, with combined global land and ocean surface temperatures rising 1.12 degrees Fahrenheit (0.62 degrees Celsius) above normal, the National Oceanic and Atmospheric Administration said Wednesday.

In the U.S., it was the 23rd warmest year on record and the 14th year in a row with an annual temperature above the long-term average, according to NOAA's preliminary analysis.

Meanwhile, the extent of Arctic sea ice in the summer - a key indicator of global warming - was at its third lowest level, behind 2007 and 2008.

Most atmospheric scientists attribute most of the warming seen in recent decades to gases released into the air by industrial processes and gasoline-burning engines.

Australia's floods, which started in late November, have been linked to the La Nina weather phenomenon, which refers to cooler than normal surface sea temperatures in parts of the Pacific, causing disruptions in weather patterns. La Nina occurs naturally, and the link to climate change remains unclear, said Omar Baddour of the World Meteorological Organization.

"But as we know, extreme events whether their cause is due to La Nina or El Nino or other factors, will be more intense in the era of climate change," he added.

Reinsurer Munich Re counted nearly 1,000 natural disasters in 2010 - nine-tenths of them weather-related - the second highest number since 1980. The resulting economic losses totaled $130 billion, the German company said earlier this month.

"The high number of weather-related natural catastrophes and record temperatures both globally and in different regions of the world provide further indications of advancing climate change," Munich Re said.

Scientists caution against drawing conclusions about climate change from a single storm, flood, cold snap or heat wave. Natural variability is and will always be a factor when it comes to extreme weather.

Still, single events can be useful in highlighting shortcomings in our preparedness for a warmer world more prone to extremes, said Markku Rummukainen, a climate scientist at Lund University in Sweden.

"For example, that Hurricane Katrina hit New Orleans does not have to have anything to do with climate change, but it revealed vulnerabilities that hadn't been considered," said Rummukainen, who is also involved in drafting the next report by the U.N.'s expert panel on climate change. "It remains to be seen what conclusions can be drawn in Australia."

Source:
Lake Wylie Pilot,"Australia's floods a glimpse of warmer future",By Karl Ritter, accessed January 15, 2011

Climate change leaves Assam tea growers in hot water

Climate change is affecting the cultivation of Assam tea, with rising temperatures reducing yields and altering the distinctive flavor of India's most popular drink, researchers say.

High hills and abundant rainfall make the north-eastern state of Assam an ideal place to grow tea, with 850 gardens over 320,000 hectares (593,000 acres) producing the majority of the country's harvest. But in the last 60 years, rainfall has fallen by more than a fifth and minimum temperature has risen by a degree to 19.5C.

"This is clearly climate change, and it is bound to have major impact on the tea industry," said Debakanta Handique, a climate scientist in Assam.

The Tea Board of India said it had recorded a steady decline in tea production in recent years. In 2007, Assam produced 512,000 tons of tea. By 2008 this had declined to 487,000 tons, with estimated production in 2009 down again to 445,000. A further decrease is expected this year.

Mridul Hazarika, director of Tocklai Tea Research, the oldest tea research station in the world, said rainfall and minimum temperature were two of the most important factors affecting both quality and quantity of harvests.

"The decline has been taking place although there has been an increase in the area of tea cultivation as new gardens have come up, and many gardens have added new areas for tea plantation. This is an indication of the seriousness of the threat," said Hazarika. Efficient rainwater harvesting and new breeds of tea plants were needed to reverse the trend.

"Changes have already been observed in the flavor, but it is not possible to blame only climate change for this," he said. "Other factors like the fertilizers used and cultivation methods might also be partly responsible."

The changing taste of Assam tea is a serious concern for growers. Sudipta Nayan Goswami, an Assam-based planter, said subtle changes had already been observed: "The flavor has changed from what it was before. The creamy and strong flavor is no more."

"There is a huge demand for Assam tea abroad, and this is due to its strong, bright flavor. The changes will sharply hamper the demand for this variety of tea abroad."

Source:
The Guardian,"Climate change leaves Assam tea growers in hot water", accessed December 28, 2010

Wolverine latest wildlife endangered by climate change

Climate change may spell disaster for wolverines (left), a reclusive resident of the mountains of the Northwest, but other species are in more imminent danger and will delay protection for the small, ferocious mammals, wildlife officials said Monday.

The population of wolverines in the contiguous United States has rebounded to an estimated 250 to 300 since the early 20th century, when predator control in the West nearly wiped them out, the U.S. Fish and Wildlife Service said in its report.

The U.S. Fish and Wildlife Service said in their report that the wolverine warrants protection under the Endangered Species Act.

"After review of all available scientific and commercial information, we find that the North American wolverine occurring in the contiguous United States is a distinct population segment and that addition of this population to the lists of endangered and threatened wildlife and plants is warranted," said the agency.

The agency said the impact of climate change constitutes a threat to the contiguous U.S. population of the wolverine and will likely be irreversible within the foreseeable future. The population of the wolverine of North America is likely to become in danger of extinction in the foreseeable future due to destruction, modification and curtailment of its habitat and range. (Left: historical wolverine distribution in western US)

The wolverine is the largest member of the weasel family, weighing up to thirty pounds. With its dark, shaggy hair and short bushy tail, the wolverine looks something like a small bear. It lives in northern forests. Wolverines are cousins to everything from sea otters to skunks. They are known for their voracious appetites, cantankerous dispositions, skunk-like scent for defense and preference for extreme alpine environments.

Wolverines need deep snow for successful wolverine reproduction because female wolverines dig elaborate dens in the snow for their offspring. The den structures are thought to protect wolverine kits from predators as well as harsh alpine winters. However, warmer winter temperatures are reducing the snow pack in the West, making climate change the "primary threat to the wolverine population," the report said.

Environmental models project the wolverines' habitat will shrink by roughly a quarter by 2045 and nearly two-thirds by 2099, agency wildlife biologist Shawn Sartorius said. (at left:Historical wolverine distribution overlaid on map of probable snow cover during denning period.)

That means the animals will not be added to the federal Lists of Endangered and Threatened Wildlife and Plants. Instead, it will join the sage grouse, plains bison and hundreds of other species on a candidate species list awaiting federal protection.

While the polar bear in 2008 was the highest profile species to receive U.S. government protection because of the warming global climate, the wolverine is also affected.

Scientists say wolverine numbers in the high country of Idaho, Montana, Washington and Wyoming have dwindled to fewer than 300 and they are virtually gone from the rest of their historic range in the lower 48 states -- including Michigan where the University of Michigan mascot is the wolverine. (At right: recent distributions of wolverines)

Wolverines, which eat meat and range from 17 to 40 pounds, need deep snow in seclusion to reproduce and raise their young. Mother wolverines dig elaborate snow caves for dens.

A study by the University of Washington and U.S. Forest Service Rocky Mountain Research Station predicts that a warming West will cut suitable wolverine habitat by 23 percent in 2045 and by 63 percent in 2099.

"The threats to the wolverines are long-term due to the impacts of climate change on their denning habitat, especially important to assist the species in successfully reproducing," said Steve Guertin, the U.S. Fish & Wildlife director for the agency's mountain-prairie region. "If we work with state and other partners to help the wolverine now, we may be able to counter the long-term impacts of climate change on their habitat and keep them from becoming endangered."

Extreme winter sports are making it even more difficult for wolverines, with snow-mobliers and skiers seeking the rugged and remote terrain preferred by the people-shy animals.

But Fish and Wildlife officials say the animals must get in line behind other species deemed by the service to have a higher priority as candidates for listing.

Conservation groups praised the government's decision to acknowledge the wolverine's dwindling population, but this does not does not result in a plan to protect them.

"It's a tough species to restore because we still know very little about them but it is frustrating and disappointing that we will have to wait for years until they're actually listed," said David Gaillard, Rocky Mountain representative with Defenders of Wildlife.

Wolverine whereabouts and numbers have been tracked only recently, with an estimated 100 in the Sawtooth Range of central Idaho and a high-density population of up to 50 animals in Glacier National Park (left).

Development, including cities, roads and ski resorts, has confined wolverine range to isolated islands. Scientists say that places the animals at undue risk by forcing them to wander hundreds of miles in search of mates. The distance between the semi-isolated populations is growing, making it more difficult for the wolverine groups to exchange genes and maintain a viable population.

Environmentalists last petitioned in 2000 to have wolverines added to the endangered species list. Eight years later, the government said protections were not warranted.

Conservation groups sued, forcing the Fish and Wildlife Service to revisit -- and now reverse -- the decision by the administration of former President George W. Bush.

Wolverines join more than 250 animal and plant species considered candidates for federal protections.

The wolverine has a broader range in Canada and Alaska, territory separate from the newly designated distinct population segment in Montana, Idaho, Washington, Wyoming, Colorado, Oregon, Utah and California.

In Canada, wolverines are considered endangered in the eastern part of the country and a species of special concern in the western part of the nation.

Source:
Reuters, "Wolverine latest wildlife endangered by climate change", accessed December 15, 2010
Denver Post, "Feds: Wolverine warrants protection", by Harold Pankratz, accessed December 15, 2010
Google News, "Feds: Wolverines need protection but have to wait", accessed December 15, 2010

Colder winters possible due to climate change: study

Climate change could lead to colder winters in northern regions, according to a study by the Potsdam Institute for Climate Impact Research on Tuesday.

Vladimir Petoukhov, lead author of the study, said a shrinking of sea ice in the eastern Arctic causes some regional warming of lower air levels and may lead to anomalies in atmospheric air streams, triggering an overall cooling of the northern continents.

"These anomalies could triple the probability of cold winter extremes in Europe and northern Asia," he said. "Recent severe winters like last year's or the one of 2005/06 do not conflict with the global warming picture but rather supplement it."

Petoukhov, whose study is entitled "A link between reduced Barents-Kara sea ice and cold winter extremes over northern continents," said in a statement a warming of the air over the Barents-Kara Sea appeared to bring cold winter winds to Europe.

"This is not what one would expect," Petoukhov said. "Whoever thinks that the shrinking of some far away sea ice won't bother him could be wrong."

The U.N. panel of climate scientists say a creeping rise in global temperatures will bring ever more floods, droughts, heat waves and rising sea levels.

Almost 200 nations meet in Mexico from November 29 to December 10 to try to agree a "green fund" to help poor countries deal with climate change and other steps toward an elusive treaty to tackle global warming.

Source:
Reuters, "Colder winters possible due to climate change: study", accessed November 17, 2010

Brown bruins could displace polar bears, scientists say

Scientists are warning that polar bears, which evolved quickly to dine mainly on seals (left), could face formidable competition as brown bears expand northward with global warming.

The iconic white bruins exist almost entirely on a meat diet, while their omnivorous southern cousins will chow down on almost any animal flesh and gorge themselves on berries.

In fact, one recent study predicts that polar bears may be forced to eat the eggs of snow geese (right) to fill their bellies.

Another study, published Nov. 5 on an online research journal called PLoS One, says polar bears may be at a disadvantage precisely because they have adapted over the past million years to a diet of seals.

The polar bear developed smaller molars and a low, slender skull which allow it to "efficiently process" seal flesh and blubber.

Another paper that examined the "extremely rapid evolution" of polar bears notes that their skulls are less suited to processing tough, hard-to-chew diets with lots of vegetation.

Although the heads and muscle-power of two species are similar, tests reveal the polar bear's skull is a "weaker, less work-efficient structure," and does not appear well suited to large amounts of chewing, the study's authors say.

Compared with other bears, polar bears have low flat skulls with high-sitting eyes, which likely developed as an advantage so they could thrust their heads into breathing holes or pupping dens. Because polar bears feed almost exclusively on young ringed and bearded seals, they don't need large skulls like lions or wolves, which regularly eat prey larger than themselves, the study says.

And polar bears also lack the well-developed "blade-like" teeth because they feed almost exclusively on blubber and flesh. These, unlike bone, require little or no chewing or tearing prior to swallowing, the study notes.

Brown bears eat animals when available, but they also eat large amounts of plants in the summer, including grasses, which require a lot of work before they can be swallowed.

So, increased competition from brown bears expanding their range northward is likely to present "a significant challenge" to polar bears, the study concludes, pointing to areas where Arctic foxes overlap with southern red foxes, which end up controlling prime feeding and denning areas.


Source:
The Province, "Brown bruins could displace polar bears, scientists say", accessed November 9, 2010

Grim outlook for grizzlies in Yellowstone region

With milder winters affecting their food and hibernation habits, they're forced into a meat-dependent diet – putting them at odds with humans and livestock. In the end , they could become as despised as western wolves.

Magnificent and wild, the grizzly bear of the American west has a fearsome reputation. But as a population boom forces them from their deep wilderness habitat of the Rocky Mountains, their increasingly close encounters with humans are altering their lifestyles, making them lazy and fat, conservation experts say.

"We've got bears spending the whole summer eating oats in the field, out there with the elk and the deer, and getting fatter and fatter," said Jamie Jonkel, a grizzly manager and wildlife conflict specialist with Montana Fish, Wildlife and Parks, the state government's conservation agency.

"They've started really loving the good life, much like the average American," said Jonkel, who led a tour of reporters from the Society for Environmental Journalists.

"Some of the grizzlies still move into the high country in the summer, but some of them just set up shop and don't move. You can see grizzlies out there in the fields all day lazing about grazing on alfafa while a kid is kicking a soccer ball around," he said.

A number of complex factors are believed to be working against grizzlies, including climate change. Milder winters have allowed bark beetles to decimate the white-bark pine, whose nuts are a critical food source for grizzlies. Meanwhile, there has been a slight seasonal shift for plants that grizzlies rely on when they prepare to hibernate and when they emerge in the spring, changing the creatures' denning habits.

The result, some biologists say, is that bears accustomed to feasting on berries and nuts in remote alpine areas are being pushed into a more meat-dependent diet that puts them on a collision course with the other dominant regional omnivore: humans.

"A grizzly is a top-level carnivore; at times he will act like one," said Chuck Neal, author of "Grizzlies in the Mist" who lost a botanist friend to a grizzly attack this year. "People are a readily available source of high-quality protein. We eat too much and exercise too little. We're like a hot dog on two legs."

Chris Servheen, a grizzly researcher for the U.S Fish and Wildlife Service, downplays the role of white-bark pine loss, noting that grizzlies are highly adaptive and don't specialize on white-bark pine.

"It's easier to describe what they don't eat than what they do," Servheen said.

Still, the evidence is not encouraging for the grizzly, which was placed on the endangered species list in 1975.

Two years ago, 52 grizzlies died from human causes in the Yellowstone area. As of the end of October, 48 bears have been killed this year although some rangers estimate that a more accurate count is near 60. If forecasts prove correct, the tally is only going to get worse.

The tally of grizzly deaths in the states bordering the greater Yellowstone region is fast approaching the worst on record. And that's before the numbers come in from the current hunting season, a time when accidental grizzly shootings are traditionally high. In Wyoming, more bears were killed this year than ever, including a bear shot by a hunter last week.

Other bear species across the region from New Mexico to the Canadian border are and roaming into backyards to get at dog food, ransacking campgrounds, and challenging elk and deer hunters for their kills.

There is another chilling footnote to 2010: For the first time anyone can remember, grizzlies attacked and killed two people. In June, Neal's friend, 70 year old Erwin Evert, the botanist, was alone on an afternoon hike to research the region’s plants and animals, when he stumbled upon a "nuisance" bear west of Cody, Wyo., just as it was coming out of anesthesia after being relocated by wildlife officials. The adult male grizzly was located the next day by trackers following a signal from a radio collar that had been placed around the bear's neck.

The animal was shot and killed from a helicopter, and died about 2 miles from where Evert's body was found. A lab analysis confirmed that it was the same animal that mauled Evert.

In July, near Cooke City, Mont., an undernourished sow with three cubs stalked a group of sleeping campers over several hours, attacking two people before killing one man.

Wildlife officials euthanized the mother grizzly bear after DNA tests confirmed that the sow and her cubs were responsible for a triple mauling that killed a Michigan man and injured two other campers.

Montana Fish, Wildlife and Parks said in a statement that hair, saliva and tissue samples tested at a Laramie, Wyo., lab determined the adult bear was the same one that rampaged through near Soda Butte Campground Yellowstone National Park early Wednesday.

The tests also showed probable cause as to why the bears attacked the humans; they were hungry. In clinical terms the report describes the mother bear as thin and undernourished. Her three offspring were also nutritionally stressed. The female's stomach contents show she had not eaten pine nuts, nor much of anything else, before the attack. The sow may not have been able to provide enough milk for her cubs.

After the attack, authorities captured the four bears near the site, surmising that the family was resting before returning to its kill. The mother was euthanized and the three cubs were taken to a zoo in Bozeman, where they were fed meat and fruit, which they readily ate.

Maulings of humans are up around the Rockies, occurring at twice the yearly average in Wyoming, and grizzlies in record numbers are being euthanized by wildlife managers because of persistent run-ins with people, including hunting livestock.

"In 2008 we had a huge pile-up of dead bears; this year could get to that," said Louisa Willcox, who studies bears for the Natural Resources Defense Council. "These conflicts should be seen as warning signs, flashing yellow lights."

As they continue to interact with humans and harass and kill livestock, bears risk earning the type of scorn heaped on wolves in the region, which are viewed less as an emblematic creature of the West and more as varmints that plague the landscape.

"Public tolerance is starting to wane somewhat," said Mark Bruscino, bear management supervisor for Wyoming's Department of Game and Fish. "You can look at the mountains and know there are grizzly bears there and that sits pretty good with people. But, when you go to your child's 4-H facility and bears have ruined the place, that changes things. People in Wyoming think they have enough bears."

If a shift in public perception drives changes in policy, grizzly bears could be legally hunted in the Lower 48 for the first time in nearly four decades.

To Bruscino, it's simply wise game management to "harvest" animals, and might be better for bears. "Right now there's no value on bears," he said. "If people are allowed to compete for a limited number of hunting licenses, people will start to [ascribe] more value to bears."

The animals may be a victim of the success of conservation efforts. In 2007, the species was considered to have recovered enough to be taken off the endangered species list. But a court overturned that decision last year and returned the bears to "threatened" status, a decision U.S. Fish and Wildlife is appealing.

Wildlife officials meeting last week in Montana concluded the region's grizzly population is about 600, nearly three times the 1975 numbers. Some concluded that the increased bear conflicts signal that the region has reached its carrying capacity for grizzlies.

"The bucket is getting full," said Chuck Schwartz, who heads the federal Interagency Grizzly Bear Study Team. "You have to think about how many bears we should have in this ecosystem. The greatest single predictor for conflict is the number of bears."

With more bears and more people stuffed into the 22,000 square miles of bear habitat, something has to give, and no one here has a simple answer.

Source:
The Guardian, "Grizzly bears enjoy the good life as they move closer to human settlement", by Suzanne Goldenberg, accessed November 7, 2010
Los Angeles Times, "Grim outlook for grizzlies in Yellowstone region", by Julie Cart, accessed November 7, 2010