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A Chilling Possibility;and a real one..... |
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carbon20
Moderator Joined: April 08 2006 Location: West Australia Status: Offline Points: 65816 |
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Posted: June 18 2016 at 3:17pm |
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A Chilling PossibilityBy disturbing a massive ocean current, melting Arctic sea ice might trigger colder weather in Europe and North America.Listen to this story via streaming audio, a downloadable file, or get help. March 5, 2004: Global warming could plunge North America and Western Europe into a deep freeze, possibly within only a few decades. That's the paradoxical scenario gaining credibility among many climate scientists. The thawing of sea ice covering the Arctic could disturb or even halt large currents in the Atlantic Ocean. Without the vast heat that these ocean currents deliver--comparable to the power generation of a million nuclear power plants--Europe's average temperature would likely drop 5 to 10°C (9 to 18°F), and parts of eastern North America would be chilled somewhat less. Such a dip in temperature would be similar to global average temperatures toward the end of the last ice age roughly 20,000 years ago. Some scientists believe this shift in ocean currents could come surprisingly soon--within as little as 20 years, according to Robert Gagosian, president and director of the Woods Hole Oceanographic Institution. Others doubt it will happen at all. Even so, the Pentagon is taking notice. Andrew Marshall, a veteran Defense Department planner, recently released an unclassified report detailing how a shift in ocean currents in the near future could compromise national security. "It's difficult to predict what will happen," cautions Donald Cavalieri, a senior scientist at NASA's Goddard Space Flight Center, "because the Arctic and North Atlantic are very complex systems with many interactions between the land, the sea, and the atmosphere. But the facts do suggest that the changes we're seeing in the Arctic could potentially affect currents that warm Western Europe, and that's gotten a lot of people concerned."
The view from orbit clearly shows a long-term decline in the "perennial" Arctic sea ice (the part that remains frozen during the warm summer months). According to a 2002 paper by Josefino Comiso, a climate scientist at NASA's Goddard Space Flight Center, this year-round ice has been retreating since the beginning of the satellite record in 1978 at an average rate of 9% per decade. Studies looking at more recent data peg the rate at 14% per decade, suggesting that the decline of Arctic sea ice is accelerating. Some scientists worry that melting Arctic sea ice will dump enough freshwater into the North Atlantic to interfere with sea currents. Some freshwater would come from the ice-melt itself, but the main contributor would be increased rain and snow in the region. Retreating ice cover exposes more of the ocean surface, allowing more moisture to evaporate into the atmosphere and leading to more precipitation. Because saltwater is denser and heavier than freshwater, this "freshening" of the North Atlantic would make the surface layers more buoyant. That's a problem because the surface water needs to sink to drive a primary ocean circulation pattern known as the "Great Ocean Conveyor." Sunken water flows south along the ocean floor toward the equator, while warm surface waters from tropical latitudes flow north to replace the water that sank, thus keeping the Conveyor slowly chugging along. An increase in freshwater could prevent this sinking of North Atlantic surface waters, slowing or stopping this circulation. "Other important pieces of the puzzle, like rainfall, sea-surface temperatures, and oceanic winds, are also detected by AMSR-E. Looking at those variables together should help scientists assess the likelihood of a change in the Atlantic currents," adds Spencer. Once considered incredible, the notion that climate can change rapidly is becoming respectable. In a 2003 report, Robert Gagosian cites "rapidly advancing evidence [from, e.g., tree rings and ice cores] that Earth's climate has shifted abruptly and dramatically in the past." For example, as the world warmed at the end of the last ice age about 13,000 years ago, melting ice sheets appear to have triggered a sudden halt in the Conveyor, throwing the world back into a 1,300 year period of ice-age-like conditions called the "Younger Dryas." Will it happen again? Researchers are scrambling to find out. On Feb. 13, an expedition set sail from Great Britain to place current-monitoring sensors in the Atlantic Ocean that will check the Gulf Stream for signs of slowing. The voyage is the latest step in a joint US / UK research project called Rapid Climate Change, which began in 2001. Another international project, called SEARCH (Study of Environmental Arctic CHange), kicked off in 2001 with the goal of more carefully assessing changes in Arctic sea ice thickness. Much depends on how fast the warming of the Arctic occurs, according to computer simulations by Thomas F. Stocker and Andreas Schmittner of the University of Bern. In their models, a faster warming could shut down the major Atlantic current completely, while a slower warming might only slow the current for a few centuries. And, inevitably, the discussion turns to people. Does human industry play a major role in warming the Arctic? Could we reverse the trend, if we wanted to? Not all scientists agree. Some argue that the changes occuring in the Arctic are consistent with large, slow natural cycles in ocean behavior that are known to science. Others see a greater human component. "The sea ice thawing is consistent with the warming we've seen in the last century," notes Spencer, but "we don't know how much of that warming is a natural climate fluctuation and what portion is due to manmade greenhouse gases." If the Great Conveyor Belt suddenly stops, the cause might not matter. Europeans will have other things on their minds--like how to grow crops in snow. Now is the time to find out, while it's merely a chilling possibility. Web Links Global Hydrology and Climate Center -- a joint NASA / University of Alabama at Huntsville center dedicated to studying the Earth's climate system AMSR-E -- NASA home page for the Japanese-built satellite sensor mentioned in this article Aqua -- information about the AMSR-E sensor on NASA's Aqua satellite. Aqua is an international project supported by the United States, Japan and Brazil. SEARCH -- home page of the Study of Environmental Arctic Change Rapid Climate Change program -- home page More about sudden climate change: Abrupt climate change, from the Woods Hole Oceanographic Institute; Climate change and Arctic sea ice, from Greenpeace; Climate rides on ocean conveyor belt, from Environmental News Network; The Great Ocean Conveyor, from the David Suzuki Foundation; The Pentagon's weather nightmare, from Fortune magazine; The discovery of rapid climate change, from Physics Today Join our growing list of subscribers - sign up for our express news deliveryand you will receive a mail message every time we post a new story!!! |
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Ok so Day After Tomorrow movie was not exact but looks like we could have some cooling in the next 20 years because of warming. But funny how the earth takes care of itself. I keep saying we have too many people, we need a pandemic or something to reduce the population. Not a nice thing to say but just the way I feel.
What that means for me is I will continue to do a rebuild on my wood so that year after year I build to 5 to 6 cords of wood, (I have only built to 4 in winter), put that hole in my 1/2 man saw so it can be a two man saw (I have the extra handle), make or buy a sawbuck for cutting wood into correct chunks, and make sure my son knows how to sharpen the 1/2 man saw. As we all know TSWHTF eventually, it may not be in my lifetime but it could be in my son's lifetime and he has a prepper mind because he has listened to me for so long. I try to prepare for all contingencies, just put 250 sand bags away in my shed in case we have a flood,thatis enough to cover some main areas. Be prepared! |
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OK, so a nice 4 hour project for me a folding sawbuck. I can store it in my garage with all the wood I have to cover my windows which I have not completed yet! It will be a lot of wood if I have enough cut to fit all my windows and I am running out of room.
Any suggestions on storage folks! |
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OriginalHappyCamper
Valued Member Joined: December 25 2013 Location: Silverton, Or Status: Offline Points: 2850 |
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move to a larger place in the mountains away from the cities.
We did.
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Jesus Christ died and was raised on the third day, the only "God" to overcome death.
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Dutch Josh
Adviser Group Joined: May 01 2013 Location: Arnhem-Netherla Status: Offline Points: 95567 |
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This over 12 years old article (from expres science news ?) does not mention global green house gas. Since march 2004 a lot has happened. And yes the gulfstream is slowing down. Medclinician did start a similar story http://www.avianflutalk.com/coming-of-the-ice-age-2016_topic35172_post259652.html?KW=#259652
The gulfstream slowing down will proberbly mean that other gulfstreams will emerge. NE America and NW Europe have some coolling effect of Greenland (and seaice) melt. But there is not enough cold left in the Arctic, not enough cooling power, for another ice age. Gulf- and jetstreams are the results of the Earths rotation and temperature differences in sea and air. Warming of the Arctic means those temperature differences are getting smaller most of the time. The jetstream as a result starts meandering more extreme. Bringing snow to Saudi Arabia, warm temperatures to the North Pole. Sweet melting water from Greenland is lighter than the (warmer) salt water so you have a "lens" , a thin layer, of sweet melt water around Greenland. That is causing a cooling effect in its surroundings unless other events block that cooling. If warm air from central Europe or more western parts of North America are stronger that stops the cooling effect in that area. Green house gases are now above 400 parts per million for CO2, when you add up other global warming gases you now are at a global average of 490 ppm. What I understand is that those kind of levels of greenhouse gases belong to a temperature several degrees celsius higher when you look at history. Paleo-climotologists did study this. Higher temperatures mean higher sea levels. With 490 ppm green house gas you may expect a sealevel rise of several meters-even the IPCC (International Panel on Climate Change) draws that conclussion. The IPCC expected a sealevelrise of up to 1 meter untill 2100. After that sealevelrise would increase further. Recent findings indicate that the IPCC models are much to optimistic. The Arctic sea-ice is already in a condition now that the IPCC expected it to be by 2080. Methane in the Arctic is flowing up from de-frozen permafrost bringing greenhouse gas levels higher faster. Water in the Arctic preservers heat that ice would reflect. So in the Arctic there are several factors pushing up the temperature.
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We cannot solve our problems with the same thinking we used when we created them.
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