Uh oh... global warming is NOT on predicted path
quote:COLUMBUS , Ohio - A new report on climate over the world's southernmost continent shows that temperatures during the late 20th century did not climb as had been predicted by many global climate models.
This comes soon after the latest report by the Intergovernmental Panel on Climate Change that strongly supports the conclusion that the Earth's climate as a whole is warming, largely due to human activity.
It also follows a similar finding from last summer by the same research group that showed no increase in precipitation over Antarctica in the last 50 years. Most models predict that both precipitation and temperature will increase over Antarctica with a warming of the planet.
David Bromwich, professor of professor of atmospheric sciences in the Department of Geography, and researcher with the Byrd Polar Research Center at Ohio State University, reported on this work at the annual meeting of the American Association for the Advancement of Science at San Francisco.
"It's hard to see a global warming signal from the mainland of Antarctica right now," he said. "Part of the reason is that there is a lot of variability there. It's very hard in these polar latitudes to demonstrate a global warming signal. This is in marked contrast to the northern tip of the Antarctic Peninsula that is one of the most rapidly warming parts of the Earth."
Bromwich says that the problem rises from several complications. The continent is vast, as large as the United States and Mexico combined. Only a small amount of detailed data is available - there are perhaps only 100 weather stations on that continent compared to the thousands spread across the U.S. and Europe . And the records that we have only date back a half-century.
"The best we can say right now is that the climate models are somewhat inconsistent with the evidence that we have for the last 50 years from continental Antarctica .
"We're looking for a small signal that represents the impact of human activity and it is hard to find it at the moment," he said.
Last year, Bromwich's research group reported in the journal Science that Antarctic snowfall hadn't increased in the last 50 years. "What we see now is that the temperature regime is broadly similar to what we saw before with snowfall. In the last decade or so, both have gone down," he said.
In addition to the new temperature records and earlier precipitation records, Bromwich's team also looked at the behavior of the circumpolar westerlies, the broad system of winds that surround the Antarctic continent.
"The westerlies have intensified over the last four decades of so, increasing in strength by as much as perhaps 10 to 20 percent," he said. "This is a huge amount of ocean north of Antarctica and we're only now understanding just how important the winds are for things like mixing in the Southern Ocean." The ocean mixing both dissipates heat and absorbs carbon dioxide, one of the key greenhouse gases linked to global warming.
Some researchers are suggesting that the strengthening of the westerlies may be playing a role in the collapse of ice shelves along the Antarctic Peninsula.
"The peninsula is the most northern point of Antarctica and it sticks out into the westerlies," Bromwich says. "If there is an increase in the westerly winds, it will have a warming impact on that part of the continent, thus helping to break up the ice shelves, he said.
"Farther south, the impact would be modest, or even non-existent."
Bromwich said that the increase in the ozone hole above the central Antarctic continent may also be affecting temperatures on the mainland. "If you have less ozone, there's less absorption of the ultraviolet light and the stratosphere doesn't warm as much."
That would mean that winter-like conditions would remain later in the spring than normal, lowering temperatures.
"In some sense, we might have competing effects going on in Antarctica where there is low-level CO2 warming but that may be swamped by the effects of ozone depletion," he said. "The year 2006 was the all-time maximum for ozone depletion over the Antarctic."
Bromwich said the disagreement between climate model predictions and the snowfall and temperature records doesn't necessarily mean that the models are wrong.
"It isn't surprising that these models are not doing as well in these remote parts of the world. These are global models and shouldn't be expected to be equally exact for all locations," he said.
http://www.eurekalert.org/pub_releases/2007-02/osu-atd021207.php
This comes soon after the latest report by the Intergovernmental Panel on Climate Change that strongly supports the conclusion that the Earth's climate as a whole is warming, largely due to human activity.
It also follows a similar finding from last summer by the same research group that showed no increase in precipitation over Antarctica in the last 50 years. Most models predict that both precipitation and temperature will increase over Antarctica with a warming of the planet.
David Bromwich, professor of professor of atmospheric sciences in the Department of Geography, and researcher with the Byrd Polar Research Center at Ohio State University, reported on this work at the annual meeting of the American Association for the Advancement of Science at San Francisco.
"It's hard to see a global warming signal from the mainland of Antarctica right now," he said. "Part of the reason is that there is a lot of variability there. It's very hard in these polar latitudes to demonstrate a global warming signal. This is in marked contrast to the northern tip of the Antarctic Peninsula that is one of the most rapidly warming parts of the Earth."
Bromwich says that the problem rises from several complications. The continent is vast, as large as the United States and Mexico combined. Only a small amount of detailed data is available - there are perhaps only 100 weather stations on that continent compared to the thousands spread across the U.S. and Europe . And the records that we have only date back a half-century.
"The best we can say right now is that the climate models are somewhat inconsistent with the evidence that we have for the last 50 years from continental Antarctica .
"We're looking for a small signal that represents the impact of human activity and it is hard to find it at the moment," he said.
Last year, Bromwich's research group reported in the journal Science that Antarctic snowfall hadn't increased in the last 50 years. "What we see now is that the temperature regime is broadly similar to what we saw before with snowfall. In the last decade or so, both have gone down," he said.
In addition to the new temperature records and earlier precipitation records, Bromwich's team also looked at the behavior of the circumpolar westerlies, the broad system of winds that surround the Antarctic continent.
"The westerlies have intensified over the last four decades of so, increasing in strength by as much as perhaps 10 to 20 percent," he said. "This is a huge amount of ocean north of Antarctica and we're only now understanding just how important the winds are for things like mixing in the Southern Ocean." The ocean mixing both dissipates heat and absorbs carbon dioxide, one of the key greenhouse gases linked to global warming.
Some researchers are suggesting that the strengthening of the westerlies may be playing a role in the collapse of ice shelves along the Antarctic Peninsula.
"The peninsula is the most northern point of Antarctica and it sticks out into the westerlies," Bromwich says. "If there is an increase in the westerly winds, it will have a warming impact on that part of the continent, thus helping to break up the ice shelves, he said.
"Farther south, the impact would be modest, or even non-existent."
Bromwich said that the increase in the ozone hole above the central Antarctic continent may also be affecting temperatures on the mainland. "If you have less ozone, there's less absorption of the ultraviolet light and the stratosphere doesn't warm as much."
That would mean that winter-like conditions would remain later in the spring than normal, lowering temperatures.
"In some sense, we might have competing effects going on in Antarctica where there is low-level CO2 warming but that may be swamped by the effects of ozone depletion," he said. "The year 2006 was the all-time maximum for ozone depletion over the Antarctic."
Bromwich said the disagreement between climate model predictions and the snowfall and temperature records doesn't necessarily mean that the models are wrong.
"It isn't surprising that these models are not doing as well in these remote parts of the world. These are global models and shouldn't be expected to be equally exact for all locations," he said.
http://www.eurekalert.org/pub_releases/2007-02/osu-atd021207.php
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quote:Originally posted by spanielsells
quote:COLUMBUS , Ohio - A new report on climate over the world's southernmost continent shows that temperatures during the late 20th century did not climb as had been predicted by many global climate models.
This comes soon after the latest report by the Intergovernmental Panel on Climate Change that strongly supports the conclusion that the Earth's climate as a whole is warming, largely due to human activity.
It also follows a similar finding from last summer by the same research group that showed no increase in precipitation over Antarctica in the last 50 years. Most models predict that both precipitation and temperature will increase over Antarctica with a warming of the planet.
David Bromwich, professor of professor of atmospheric sciences in the Department of Geography, and researcher with the Byrd Polar Research Center at Ohio State University, reported on this work at the annual meeting of the American Association for the Advancement of Science at San Francisco.
"It's hard to see a global warming signal from the mainland of Antarctica right now," he said. "Part of the reason is that there is a lot of variability there. It's very hard in these polar latitudes to demonstrate a global warming signal. This is in marked contrast to the northern tip of the Antarctic Peninsula that is one of the most rapidly warming parts of the Earth."
Bromwich says that the problem rises from several complications. The continent is vast, as large as the United States and Mexico combined. Only a small amount of detailed data is available - there are perhaps only 100 weather stations on that continent compared to the thousands spread across the U.S. and Europe . And the records that we have only date back a half-century.
"The best we can say right now is that the climate models are somewhat inconsistent with the evidence that we have for the last 50 years from continental Antarctica .
"We're looking for a small signal that represents the impact of human activity and it is hard to find it at the moment," he said.
Last year, Bromwich's research group reported in the journal Science that Antarctic snowfall hadn't increased in the last 50 years. "What we see now is that the temperature regime is broadly similar to what we saw before with snowfall. In the last decade or so, both have gone down," he said.
In addition to the new temperature records and earlier precipitation records, Bromwich's team also looked at the behavior of the circumpolar westerlies, the broad system of winds that surround the Antarctic continent.
"The westerlies have intensified over the last four decades of so, increasing in strength by as much as perhaps 10 to 20 percent," he said. "This is a huge amount of ocean north of Antarctica and we're only now understanding just how important the winds are for things like mixing in the Southern Ocean." The ocean mixing both dissipates heat and absorbs carbon dioxide, one of the key greenhouse gases linked to global warming.
Some researchers are suggesting that the strengthening of the westerlies may be playing a role in the collapse of ice shelves along the Antarctic Peninsula.
"The peninsula is the most northern point of Antarctica and it sticks out into the westerlies," Bromwich says. "If there is an increase in the westerly winds, it will have a warming impact on that part of the continent, thus helping to break up the ice shelves, he said.
"Farther south, the impact would be modest, or even non-existent."
Bromwich said that the increase in the ozone hole above the central Antarctic continent may also be affecting temperatures on the mainland. "If you have less ozone, there's less absorption of the ultraviolet light and the stratosphere doesn't warm as much."
That would mean that winter-like conditions would remain later in the spring than normal, lowering temperatures.
"In some sense, we might have competing effects going on in Antarctica where there is low-level CO2 warming but that may be swamped by the effects of ozone depletion," he said. "The year 2006 was the all-time maximum for ozone depletion over the Antarctic."
Bromwich said the disagreement between climate model predictions and the snowfall and temperature records doesn't necessarily mean that the models are wrong.
"It isn't surprising that these models are not doing as well in these remote parts of the world. These are global models and shouldn't be expected to be equally exact for all locations," he said.
http://www.eurekalert.org/pub_releases/2007-02/osu-atd021207.php
I think you're highlighting one sentence without looking at the whole context of the article. The researcher is talking about what could well be a signal-to-noise-ratio-problem on one part of the globe.
On the other hand, he acknowledges that it might not be warming over the Antarctic, he gives some reasons (apparently not included in the current models) why it might not be. When they figure that out, they'll adjust their climate models to reflect the new understanding and the prediction for average global temperature increase over the next century will decrease by some fraction of a degree.
But I'm not saying the climate models are right. The climate models were in their infancy ten years ago and now are like teenagers: only worth a little bit, and then only some of the time.
But warming is real.
(I've edited this damn response three times now. This seems like an especially good time to be polite. That, and I can't seem to put together a coherent paragraph this evening.)0 -
Climate "models" are manmade and are based on assumptions not KNOWN to be true. Any of the variables introduced to the "models" could be the equivalent to basing any scientific model on the assumption that the earth is flat.
One day we are told that coffee is bad for you. Then we are told that it's good for you. Then we are told that pregnant women can get away with a cup of coffee a day. Tomorrow we'll hear about increases in sudden infant death syndrome because the mother drank a cup of coffee per day during whichever trimester of her pregnancy. China will soon overtake America in the production of greenhouse gases. Nobody is trying to make China pony up $$$ with a phony Kyoto treaty. This isn't about the environment. It's about creating global socialism in which the rich (Americans) are eaten to feed non-productive citizens of our planet.0 -
quote:Originally posted by idsman75
Climate "models" are manmade and are based on assumptions not KNOWN to be true. Any of the variables introduced to the "models" could be the equivalent to basing any scientific model on the assumption that the earth is flat.
One day we are told that coffee is bad for you. Then we are told that it's good for you. Then we are told that pregnant women can get away with a cup of coffee a day. Tomorrow we'll hear about increases in sudden infant death syndrome because the mother drank a cup of coffee per day during whichever trimester of her pregnancy. China will soon overtake America in the production of greenhouse gases. Nobody is trying to make China pony up $$$ with a phony Kyoto treaty. This isn't about the environment. It's about creating global socialism in which the rich (Americans) are eaten to feed non-productive citizens of our planet.
Climate models absolutely are man-made, and absolutely rely on assumptions. That is what a model is: a simplification of the universe. Sometimes a modeler has to assume that a certain factor is unimportant, and sometimes we don't understand that factor so we go with an assumption to complete the model. At that point the model is a testable hypothesis: if it doesn't predict reality, then there's something wrong with the assumptions.
Some of the most interesting stories about progress in science came about because something was so very wrong with the model assumptions that as you put it, the researchers might as well have gone with "the assumption that the earth is flat." But that's how science works: set up a model and try to knock it over. When you succeed, figure out which assumption (=hypothesis) is to blame, modify it, and try again.
About being told one thing regarding the health risks of coffee this week and another thing next week, etc: I believe that's more of a function of the news media than of science, and science journalists are actively discussing this problem. News doesn't sell unless it's exciting and for anybody who's not actually a scientist, the interesting science is usually occurring at the fringes of knowledge, or else represents a paradigm shift. Scientists get it wrong sometimes, and that's why the scientific process is structured like it is (see above paragraph): it is a self-correcting discipline. Unfortunately, scientists get it wrong much more often when they are at the cutting edge of what we know or when they are suggesting a paradigm shift.
I'm on the verge of hijacking this thread so I'll stop there.0
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