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[energyresources] Re: Paradoxically, global warming mayprecipitate an ice age.... by Tim Jones 21 December 2003 04:53 UTC |
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At 7:10 AM -0600 12/20/2003, npat1@juno.com wrote:
See> > ... while the globe as a whole gets warmer by tiny> fractions of 1 degree Fahrenheit annually, ...(snip) Tim, Do you know the numbers (tiny fractions of 1 degree Fahrenheit annually) ?
I disagree. The temperature rise seems to me to go from about a hundredth of a degree lastI think the fractions of increase in global temperatures are NOT so tiny. The NOT so tiny increases in temperatures and humidity will overwhelm cooling effects due from the change in path, slow down or shut down of the Gulf Stream.
I'm not qualified to second guess the Woods Hole folks. What I read every day is that glaciersThe researchers at Woods Hole are getting people worked up over something that will not be very serious or noticeable, if at all, on climate time scale (more than a few months).
> > Joyce says. So while the globe as a whole gets > > warmer by tiny fractions of 1 degree Fahrenheit> annually, the North Atlantic region could, in a decade, > get up to 10 degrees colder. What worries researchers > at Woods Hole is that history is on the side of rapid > shutdown. They know it has happened before. "(snip) I have not researched this myself, & I don't have Internet here at home so I am not looking up the linked information.
High speed Internet (Google) for research is invaluable. But often the data you want you have to pay for through a subscription to a scientific journal. In this case - "Nature."
However, I am doubtful that there is good data that shows a rapid decrease in climate
What does a decrease in climate mean?
for the region during a period of rapid global warming when the starting condition are like today.
There are no starting conditions that recapitulate what is happening today.
The last period of rapid global warming during an already warm period preceded the Paleocene Eocene Thermal Maximum (PETM) 55 million years ago. Do researchers at Woods Hole have good data on what happened preceding the PETM?
> >What worries researchers > > at Woods Hole is that history is on the side of rapid > > shutdown. They know it has happened before. "
I'd suggest e-mailing them for verification of this assertion. <education@whoi.edu> for starts.
I would appreciate additional replies on this threat include a Cc To: Paleontology_and_Climate@yahoogroups.com (P&C) It would be helpful if you first became a member of my P&C yahoo group, which has open membership with post currently not moderated until after posted, see: http://groups.yahoo.com/group/Paleontology_and_Climate/
Done
Pat Minnesota
Tim Texas
Tim Jones writes:Melting of the arctic ice cap..... http://www.discover.com/sept_02/featice.html (excerpt) "It could happen in 10 years," says Terrence Joyce, who chairs the Woods Hole Physical Oceanography Department.(snip)> The trend could cause a little ice age by subverting > the the Gulf Stream, laden with heat soaked up in > the tropics, meanders up the east coasts of the > United States and Canada. As it flows northward, > the stream surrenders heat to the air. Because the > prevailing North Atlantic winds blow eastward, a lot > of the heat wafts to Europe. That's why many > scientists believe winter temperatures on the > Continent are as much as 36 degrees Fahrenheit > warmer than those in North America at the same > latitude. Frigid Boston, for example, lies at almost > precisely the same latitude as balmy Rome. And > some scientists say the heat also warms Americans > and Canadians. "It's a real mistake to think of this > solely as a European phenomenon," says Joyce....> Joyce says. So while the globe as a whole gets > warmer by tiny fractions of 1 degree Fahrenheit> > annually, the North Atlantic region could, in a decade, > > get up to 10 degrees colder. What worries researchers> at Woods Hole is that history is on the side of rapid> > shutdown. They know it has happened before. " (snip) On Sat, 20 Dec 2003 01:32 Tim Jones writes:The greenhouse effect may precipitate an ice age in Europe and the Northern latitudes. There are corollary observations to what are described below involving the melting of the arctic ice cap disrupting circulation of the Gulf Stream, too. http://www.discover.com/sept_02/featice.html (This link may not come up so I have posted excerpts from the text following the Daily Grist introduction and the ALANNA MITCHELL article.) Tim(snip) --------- Forwarded message ---------- From: Tim Jones <deforest@austin.rr.com> To: energyresources@yahoogroups.com, wsn@csf.colorado.edu Date: Sat, 20 Dec 2003 01:32:22 -0600 Subject: [energyresources] Paradoxically, global warming may precipitate an ice age.... Message-ID: <p06002009bc099a035436@[192.168.1.100]> The greenhouse effect may precipitate an ice age in Europe and the Northern latitudes. There are corollary observations to what are described below involving the melting of the arctic ice cap disrupting circulation of the Gulf Stream, too. http://www.discover.com/sept_02/featice.html (This link may not come up so I have posted excerpts from the text following the Daily Grist introduction and the ALANNA MITCHELL article.) Tim <> DAILY GRIST 18 Dec 2003 Environmental news from GRIST MAGAZINE <http://www.gristmagazine.com> Climate Change Alters Salt Levels in Atlantic Ocean, to Europe's Dismay The Atlantic Ocean seems so vast that it's almost impossible to imagine fundamentally altering it -- and yet, its salt levels have changed so drastically over the last 40 years because of global warming that the whole flow of ocean water is being disrupted, according to a study published today in the journal Nature. As the planet warms, more ocean water evaporates than normal, causing the concentration of salt to increase in certain areas -- and, because the overall salinity of the ocean must remain the same, to decrease in others. Because salty water is heavier than fresh water, these changes alter the way ocean water flows around the planet. In a kind of vicious climate-change circle, that alteration will have its own dramatic effects on the global climate, changing and redirecting such basic forces as the Gulf Stream, which keeps places like England and Ireland relatively warm and inhabitable, even though they share the same latitude as the far colder southern Alaska. If ocean salinity continues to change, the Nature study found, Northern Europe could become as much as 10 to 20 degrees cooler than it is today. straight to the source: The Globe and Mail, Alanna Mitchell, 18 Dec 2003 <http://www.gristmagazine.com/forward.pl?forward_id=1836> Atlantic's salt balance poses threat, study says By ALANNA MITCHELL Thursday, December 18, 2003 - Page A15 http://www.theglobeandmail.com/servlet/ArticleNews/TPStory/LAC/20031218/O CEANS18/TPEnvironment/ The delicate salt balance of the Atlantic Ocean has altered so dramatically in the last four decades through global warming that it is changing the very heat-conduction mechanism of the ocean and stands to turn Northern Europe into a frigid zone. The conclusions are from a study in the journal Nature that is to be published today. The study describes planet-scale changes in the regulatory function of the ocean that affect precipitation, evaporation, fresh-water cycles and climate. "This has the potential to change the circulation of the ocean significantly in our lifetime," said Ruth Curry of the Woods Hole Oceanographic Institution in Massachusetts, the study's lead author. The study catalogues profound changes in the salinity of the tropical and sub-tropical parts of the Atlantic Ocean. That part of the ocean is becoming saltier because higher average global temperatures are evaporating more ocean water than normal. Over time, that water vapour travels north and south to the poles, where it eventually replenishes colder oceans. Because the overall salt content of the world's oceans is constant, this means that as the equatorial ocean becomes saltier, the oceans at the poles are becoming less salty and more fresh. The implications of this are enormous. Until recently, scientists had no idea how critical salt levels in the oceans are to the hydrological cycle. They now understand that salinity is key to the ocean's ability to move warm water around the planet. Under normal conditions, the saltier waters of the far north and south sink from the surface of the ocean to the deep abyss. Then they are pulled along the bottom of the ocean back to the equator. As that massive amount of water moves from north to south, warm water from the southern Gulf Stream moves north closer to the ocean's surface to fill the void. It's akin to a gigantic water conveyor belt. That warm water pulled up to the north also warms the air. It is the reason England and Ireland are relatively balmy in winter and not frigid like southern Alaska, which is at the same latitude, said Professor Ransom Myers, holder of the Killam Chair in Ocean Studies at Dalhousie University in Halifax and a key researcher with the Census of Marine Life. But as the waters of the far north become less salty, they lose their ability to sink from the surface of the ocean to the abyss. The conveyor belt is slowing down and may eventually stop. "Northern Europe will likely experience a very significant cooling," Ms. Curry said, adding that it is expected to be in the order of 5 to 10 C cooler in winter in the course of 10 to 50 years, which is considered to be extremely rapid climate change. The trend in Europe will run counter to that of most of the planet, which has been warming as greenhouse gases concentrate in the atmosphere. The last time Northern Europe recorded temperatures that cold was during the so-called little ice age that lasted from 1500 to about 1800, she said. If the ocean conveyor belt shuts down entirely, Northern Europe will become as cold as Alaska and is unlikely to be able to support as many people as it now does, Prof. Myers said. "We're changing the Earth in ways that are just inconceivably large." he said. The problem is that this change feeds on itself and scientists don't know where it will stop, Ms. Curry explained. When water evaporates more quickly in the tropics -- as it is now from the effect of greenhouse gases that humans have emitted into the atmosphere -- that water vapour creates a greenhouse effect that helps to speed global climate change, including warming. In turn, that increases evaporation, which increases the greenhouse effect. And so on. <> Melting of the arctic ice cap..... http://www.discover.com/sept_02/featice.html (excerpt) "It could happen in 10 years," says Terrence Joyce, who chairs the Woods Hole Physical Oceanography Department. (excerpt)"As we continue to pile on atmospheric carbon dioxide, we're going to have more unintended consequences," says William Curry, a climate scientist. "We need to seriously consider steps to curb greenhouse gases." But first things first. Isn't the earth actually warming? Indeed it is, says Joyce. In his cluttered office, full of soft light from the foggy Cape Cod morning, he explains how such warming could actually be the surprising culprit of the next mini-ice age. The paradox is a result of the appearance over the past 30 years in the North Atlantic of huge rivers of freshwater-the equivalent of a 10-foot-thick layer-mixed into the salty sea. No one is certain where the fresh torrents are coming from, but a prime suspect is melting Arctic ice, caused by a buildup of carbon dioxide in the atmosphere that traps solar energy. The freshwater trend is major news in ocean-science circles. Bob Dickson, a British oceanographer who sounded an alarm at a February conference in Honolulu, has termed the drop in salinity and temperature in the Labrador Sea-a body of water between northeastern Canada and Greenland that adjoins the Atlantic-"arguably the largest full-depth changes observed>in the modern instrumental oceanographic record."The trend could cause a little ice age by subverting the the Gulf Stream, laden with heat soaked up in the tropics, meanders up the east coasts of the United States and Canada. As it flows northward, the stream surrenders heat to the air. Because the prevailing North Atlantic winds blow eastward, a lot of the heat wafts to Europe. That's why many scientists believe winter temperatures on the Continent are as much as 36 degrees Fahrenheit warmer than those in North America at the same latitude. Frigid Boston, for example, lies at almost precisely the same latitude as balmy Rome. And some scientists say the heat also warms Americans and Canadians. "It's a real mistake to think of this solely as a European phenomenon," says Joyce. Having given up its heat to the air, the now-cooler water becomes denser and sinks into the North Atlantic by a mile or more in a process oceanographers call thermohaline circulation. This massive column of cascading cold is the main engine powering a deepwater current called the Great Ocean Conveyor that snakes through all the world's oceans. But as the North Atlantic fills with freshwater, it grows less dense, making the waters carried northward by the Gulf Stream less able to sink. The new mass of relatively fresh water sits on top of the ocean like a big thermal blanket, threatening the thermohaline circulation. That in turn could make the Gulf Stream slow or veer southward. At some point, the whole system could simply shut down, and do so quickly. "There is increasing evidence that we>are getting closer to a transition point, from which we canjump to a new state. Small changes, such as a couple of years of heavy precipitation or melting ice at high latitudes, could yield a big response," says Joyce. In her sunny office down the hall, oceanographer Ruth Curry shows just how extensive the changes have already become. "Look at this," she says, pointing to maps laid out on her lab table. "Orange and yellow mean warmer and saltier. Green and blue mean colder and fresher." The four-map array shows the North Atlantic each decade since the 1960s. With each subsequent map, green and blue spread farther; even to the untrained eye, there's clearly something awry. "It's not just in the Labrador Sea," she says. "This cold, freshening area is now invading the deep waters of the entire subtropical Atlantic." "You have all this freshwater sitting at high latitudes, and it can literally take hundreds of years to get rid of it," Joyce says. So while the globe as a whole gets warmer by tiny fractions of 1 degree Fahrenheit annually, the North Atlantic region could, in a decade, get up to 10 degrees colder. What worries researchers at Woods Hole is that history is on the side of rapid shutdown. They know ithas happened before. " -- <http://www.groundtruthinvestigations.com/> Above post forwarded from energyresources group. Pat ________________________________________________________________ The best thing to hit the internet in years - Juno SpeedBand! Surf the web up to FIVE TIMES FASTER! Only $14.95/ month - visit www.juno.com to sign up today! Your message didn't show up on the list? Complaints or compliments? Drop me (Tom Robertson) a note at t1r@bellatlantic.net Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/energyresources/ To unsubscribe from this group, send an email to: energyresources-unsubscribe@yahoogroups.com Your use of Yahoo! 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