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 Posted: Thu Jan 29, 2009 7:23 am
Link: UN: Global warming is man-made — and getting worse, scientists concludeQuote: On Feb. 2, 2007, the UN's Intergovernmental Panel on Climate Change released a report — backed by 2,000 climate scientists from 113 countries — that attempts to put aside lingering doubts about the human role in the phenomenon. The IPCC report says man-made activities such as the burning of fossil fuels and to a lesser extent intensive agriculture are "very likely" — more than 90 per cent certain — to be behind the hotter temperatures and rising sea levels.
Some climate damage irreversibleQuote: Many damaging effects of climate change are already basically irreversible, researchers declared Monday, warning that even if carbon emissions can somehow be halted, temperatures around the globe will remain high until at least the year 3000. - - She defines "irreversible" as change that would remain for 1,000 years even if humans stopped adding carbon to the atmosphere immediately.
Global warming could create oceanic 'dead zones'Quote: Unabated global warming could lead to a serious depletion of oxygen in the world's oceans, creating "dead zones" that could remain for thousands of years, purging some areas of advanced marine life, a new study says. - - In this situation, dead zones could grow to a fifth of the world's oceanic area. Even if humankind stops emissions after 2100, it could take 2,000 years for the oceans to recover, the study says. The depletion of oxygen causes the ocean to be stripped of nutrients, the study says. This leads to large, unpredictable changes in the oceans' ecosystem structure, perhaps even calling into doubt the ocean as a source of food, the authors say. Quote: While past research has generally concluded that much of Antarctica was cooling, a new study suggests the continent is warming after all. - - "Contrarians have sometime grabbed on to this idea that the entire continent of Antarctica is cooling, so how could we be talking about global warming," said study co-author Michael Mann, director of the Earth System Science Center at Penn State University. "Now we can say: no, it's not true…. It is not bucking the trend." The study does not point to man-made climate change as the cause of the Antarctic warming — doing so is a highly intricate scientific process — but a different and smaller study out late last year did make that connection. - - The study has major ramifications for sea level rise, said Andrew Weaver at the University of Victoria in British Columbia. Most major sea level rise projections for the future counted on a cooling — not warming — Antarctica. This will make sea level rise much worse, Weaver said.
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Posted: Thu Jan 29, 2009 8:18 am
Grizzly-Polar Bear Hybrid Found
Quote: Multiple bear species, including polar bears and grizzlies, have been crossbred in zoos. Scientists just never expected a polar bear and grizzly to mate in the wild. - - Mating between the two species is more than a chance encounter, according to the scientists. "This is the first confirmed natural occurrence of something we know to be biologically possible, physiologically possible, and evolutionarily quite reasonable," Paetkau said. Lingering Questions Paetkau adds that the hybrid bear raises several questions. On one hand, he said, these chance encounters could happen periodically. But since the offspring are weird looking and probably outcasts, they may have low reproductive success and thereby fail to pass their genes on to the next generation. Polar bears would most likely prefer to mate with other polar bears and grizzlies with other grizzlies, rather than with an odd-looking hybrid, Paetkau says. Genetic analysis of "pure" polar bear DNA and "pure" grizzly DNA, he adds, shows that interbreeding has not been common. On the other hand, the warming Arctic environment is causing some animals to shift their range northward. It's possible, Paetkau says, that grizzly bears and polar bears may have more offspring-producing encounters in the future. "With one sample, we have no way of distinguishing between the possibilities," he said. "But it does make you sit up straight and want to keep track of that situation and get a sense over the next decade whether this will be a regular occurrence or whether it's a one-off."
Polar bears losing weight
Quote: He's not as fat as he would have been 15 years ago. He's probably 80-90 kilograms lighter than he would have been 15 years ago. The reason is the polar bears are ice bears and the ice is disappearing - - Polar bears don't hunt prey, they stalk it. Marine mammals are their prey and ice their essential platform. But the bears of Hudson Bay have got used to living on ice that melts completely every summer. So in late July, these bears have always been forced to come ashore, and with no ice to hunt from they just don't eat until freeze up in late November. Three bears To get through that summer of fasting the bears have to really layer on the fat before the ice breaks up. "So if that [breakup] gets shortened by two or three weeks, that's a lot of energy they don't get to store in their fat and that's pretty important to them. And that's the trend. These days breakup is, on average, 10 to 14 days earlier than a couple of decades ago. - - Not only are more cubs dying but the birth rate has dropped 15 per cent. - - Wayde Roberts "With this early breakup and the winds etc., we had a lot more bears offload north, and they're not used to dealing with the bear at that time of year," Roberts says. "In a normal year there wouldn't be a bear in that area for another month, if at all." By September 17th this year, he had 85 bear calls-- several times the normal number. "This year we're noticing already the bears are skinnier," Roberts says. "Our wildlife people are saying in actuality the bears are smaller as well. The large 1,400 to 2,000 pound bears aren't around anymore. " - - I mean I don't want to sound like a sensationalist, if the climate keeps on warming, ultimately there won't be polar bears in this part of the world.
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Posted: Fri Jan 30, 2009 11:25 am
Warming behind big increase in tree mortality in B.C., western U.S.
Quote: Warmer temperatures have dramatically increased the rate at which trees in old-growth forests are dying in parts of British Columbia and the western United States, a study says. The study, to be published in Friday's edition of the journal Science, found that mortality rates for trees in the old-growth plots in the Pacific Northwest — including parts of southern British Columbia — had doubled in 17 years. Forests in California and other states had less dramatic numbers. - - "One degree warmer may not seem like a lot, but the effects can be cumulative and put many more trees under stress, and cause a few more trees to die than used to," Harmon said. "Over long periods of time that can change the whole composition of the forest."
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Posted: Sun Feb 08, 2009 9:56 am
Rising CO2 levels acidifying oceans, threatening sea lifeQuote: “Ocean acidification is accelerating and severe damages are imminent,” according to the Monaco Declaration, a document signed by 155 marine scientists from 26 countries and issued last Friday. That could destroy coral reefs, threaten the fishing and tourism industries and affect the food supplies of millions of people unless policy makers work to curb carbon dioxide levels, the declaration said. Carbon-dioxide levels in the atmosphere have climbed sharply over the last century, largely due to human activity such as the burning of fossil fuels. The gas is one of the main "greenhouse gases" blamed by scientists for helping trap heat in the atmosphere, leading to climate change. That in itself has been blamed for damaging coral reefs, as warmer temperatures lead to the spread of coral diseases. But the oceans also absorb about a quarter of the carbon dioxide in the atmosphere, forming carbonic acid.
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Posted: Fri Feb 13, 2009 4:50 pm
Birds moving farther north in response to climate changeQuote: As the temperature across the U.S. has gotten warmer, the purple finch has been spending its winters more than 643 kilometres farther north than it used to — and it's not alone. An Audubon Society study to be released Tuesday found that more than half of 305 birds species in North America, a hodgepodge that includes robins, gulls, chickadees and owls, are spending the winter about 56 kilometres farther north than they did 40 years ago.
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Posted: Sun Feb 15, 2009 10:15 am
Tropical fish swimming north because of global warming Quote: They found fish will shift their distribution by an average of more than 40km each decade. While some fishing grounds will become richer, many species in cooler climates will go extinct. Developing countries in the tropics will suffer the biggest loss as their fish swim north to cooler waters with Nordic countries, such as Norway, ending up with the lion's share.
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