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Frog Whisperer
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Discussion Starter · #1 ·
uh yeah....watched a show on global warming the other night....yet......with a foot of snow on the ground, due to radiational-cooling, we are at -21 degrees (F) right now....
you know....the kind of cold that hurts to breath?
 

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Palm trees & sunshine!
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Touch0Gray said:
uh yeah....watched a show on global warming the other night....yet......with a foot of snow on the ground, due to radiational-cooling, we are at -21 degrees (F) right now....
you know....the kind of cold that hurts to breath?
It got close to 70F in DC the other day. We HAD a foot of snow on the ground the day before that.
 

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Frog Whisperer
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Discussion Starter · #3 ·
KenB said:
It got close to 70F in DC the other day. We HAD a foot of snow on the ground the day before that.

it's not hat I don't believe the scientists, we have had a bizarre winter here in WI. We had bitter cold and lots of snow pre-X-mas.....then mild with January being over 30 the whole month. Then..BOOM.....it hit the fan.

I am so ready for spring, the older I get the harder this gets....and the training stand is not as much fun as really riding...sigh
 

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It's all ball bearings
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Touch0Gray said:
uh yeah....watched a show on global warming the other night....yet......with a foot of snow on the ground, due to radiational-cooling, we are at -21 degrees (F) right now....
you know....the kind of cold that hurts to breath?
There's a reason why it's called global warming and not local warming...
 

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Resident Curmudgeon
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The Earth has been warming slowly since about 1830. The current question seems to be: Are man's activities accelerating that warming? As of now, no one can say for sure one way or the other.
 

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I heart team Zissou!
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Mr. Versatile said:
The Earth has been warming slowly since about 1830. The current question seems to be: Are man's activities accelerating that warming? As of now, no one can say for sure one way or the other.
... oh, and the Earth is flat too.....

ah off this goes to politics only!!!

A+

Philippe
 

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Scary Teddy Bear
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Well

Mr. Versatile said:
The Earth has been warming slowly since about 1830. The current question seems to be: Are man's activities accelerating that warming? As of now, no one can say for sure one way or the other.

we had a great discussion about this in PO a few months back, there is evidence that mans activities are propagating a great deal of this warming trend.....

check out our discussion for more info...

http://forums.roadbikereview.com/showthread.php?t=46470
 

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It's all ball bearings
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dang, i missed that last global warming thread

Some excellent posts/discussion in that thread.

Its my hope that this increased warming will shut down the "oceanic conveyor" and thrust us into a new glacial period. In a few tens (or hundreds) of thousands of years, the continetal ice sheets will scrape the landscape clean and drop it all off at Long Island (like the last glacier did). Then Long Island will literally be the trash heap of New England. :D
 

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jaded bitter joy crusher
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BenWA said:
Its my hope that this increased warming will shut down the "oceanic conveyor" and thrust us into a new glacial period.
The hypothesis that shutting down the thermohaline conveyor would throw us into a global ice age has been pretty well refuted. This did happen at the end of the last ice age, but there was a lot more ice melting then. There's just not enough ice left to do the job. There is some good popular exposition of the state of this hypothesis in the recent book "Thin Ice."

Also, under curent conditions, the loss of albedo from melting polar sea ice and continental ice caps is a larger (warming) forcing term than the (cooling) slowdown of heat transport from the Mediterranean to the North Atlantic.

Currently, the North Atlantic is warming, not cooling, despite the measured slowdown of the conveyor. I was at a conference last week where NASA's Jim Hansen was talking about warming patterns and showed a lot of data illustrating the shortcomings of the anthropogenic Heinrich-event/ice-age hypothesis.

I would like to underscore here that the question whether human activity is causing global warming is settled. Even skeptics such as Richard Lindzen and Patrick Michaels agree that the warming observed since 1860 is largely due to human interference in the atmosphere. All the scientific and political argument these days is over how bad the warming will get in the next 100 years.

The scientific part of the argument has become so solid that people who want to argue that global warming will not be so bad are now focusing on criticising the estimates of the political and economic parts of the models, which estimate how fast greenhouse gas emissions will accelerate over the coming century.

Finally, in Hansen's presentation last week, he described how his climate forecasts suggested (but did not prove conclusively) that we are approaching a point of no return over the next ten years: if the climate is on route to warm by 1 degree or less over the next century, we can probably avoid catastrophic outcomes, but if the climate warms by 2 degrees or more, we face catastrophic melting of polar ice caps and other very bad outcomes.

Because of the thermal inertia of the system what we do over the next ten or twenty years will determine which path we're on.
 

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Frog Whisperer
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Discussion Starter · #10 ·
BenWA said:
Some excellent posts/discussion in that thread.

Its my hope that this increased warming will shut down the "oceanic conveyor" and thrust us into a new glacial period. In a few tens (or hundreds) of thousands of years, the continetal ice sheets will scrape the landscape clean and drop it all off at Long Island (like the last glacier did). Then Long Island will literally be the trash heap of New England. :D

uh...isn't Long Island ALREADY the trash heap from New England?
 

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Frog Whisperer
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Discussion Starter · #11 · (Edited)
I didn't mean to start a controversy...BUT

as far as I know, this planet has been sliding in and out of VERY major climatic changes since long before man was around to screw things up...as for the earth being flat...I can't believe that came from the pen of a cyclist....I don't know about your world...but mine sure ain't FLAT....seems to me it is a LOT of UPHILL!
As to whether or not we are causing the changes, maybe yes...maybe no...but MANY years ago, when I was in college, back when dinosaurs roamed the planet, I took an astro-geo-physics class...had to write a paper for which I chose the "geo-centered" theory that was held to be the truth for a very, very long time....Interestingly enough, geo and ego use exactly the same letters.....a coincidence...perhaps....or is is a typo?

hehehehe.... yeah..let a sleeping dog lie....RIGHT..................
 

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It's all ball bearings
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for those readers who don't know what Fred is talking about,

I think Wally Broecker pioneered the idea that ocean circualation may have a significant effect on global climate. The basics of ocean circulation are that warm salty water flows on the surface from the equatorial regions towards the poles (this is NOT the Gulf Stream--entirely. The Gulf Stream is a small part of this circulation--although it is significant enough to warm northern Europe dramatically). Once at the poles, the water begins to freeze to make sea ice. Although some salt gets frozen into sea ice, much of the salt (and other seawater constituent compounds) do not freeze, causing water just under the surface to be much saltier. This very salty, very cold water sinks towards the bottom of the ocean. There are three MAJOR areas where this dense cold water pools--two of which are in the North Atlantic around Greenland/Iceland--and the third is on the continental shelf around Antarctica (probably mostly in the Ross Sea Embayment). The formation of the cold dense water in the North Atlantic (NADW--North Atlantic Deep Water) is thought to be the major "pump" for ocean circulation. Once formed, it moves back south, in a large global circulation. This is it: http://www.grida.no/climate/vital/32.htm

All of this warm water transports a lot of heat towards the poles, which regulates global temperature.

Now that you are an expert on global circulation, and have an idea that it may be a major factor in the Earth system dynamics of glacial ages (Earth orbital parameters are the outside factors that may contribute to the climate fluctuations), there are several questions that come to mind:

1. Can this ocean circulation stop?

2. How can the circulation stop?

3. What happens if it stops???


In answering these questions, remeber that these answers are based on THEORY; It is possible that they are wrong, but then again, these paleoclimatologists have been working on this problem for 40 years, and these are the ideas they have narrowed in on in that time.

1. Yes, if you stop the pump.

2. You may be able to stop the "pump" by introducing a large amount of fresh water directly to the three areas of deep water formation. The introduction of fresh water makes the surface water less salty, and therefore salty water does not descend to the ocean floor and form a current.

Scientists may have linked cold snaps--such as the Younger Dryas and the 8,200 year event (times when temperatures dipped back towards glacial period lows)--to large outbursts of northern hemisphere glacial lakes and icebergs <edit--delete long-winded explanation of glacial lakes, Heinrich layers, etc>. These fresh-water influxes likely shut down the ocean circulation for a moment--which made climate return to glacial period temperatures for a moment.

Therefore, this evidence of past fresh-water influxes gives credence to the possibility of it happening in the future...

...thus the significance of the current situation where sea ice is melting near the north pole, and maybe greater significance of the possibility for the Greenland Ice Sheet collapse (not super likely, since it is situated on land above sea level--UNLIKE the West Antarctic Ice Sheet )WAIS) which is based on land that is below sea level. The WAIS appears to be retreating. If WAIS collapses, it will be significant.

3. If the increased warming of the atmosphere is enought to create a lot of fresh water at the poles (melting of sea ice and glaciers) and eventually stops the ocean circulation, it is likely that the heat transport to the poles diminishes. This will lead to much cooler surface temperatures (air and water). No one knows if this scenario will be like the Younger Dryas (only 1,000 years of cold) or if it represents the onset of a new glacial cycle.



Like I said in another thread--2 million years ago the Earth (for some unknown reason) went into a "new" climate mode. Roughly every 110,000 years there is a glacial cycle. 100,000 years of wildly fluctuating temperatures where ice sheets wax and wane over the high latitudes, and then 10,000 years of relative calm and warm in between. Depending on whom you ask, the last 100,000 year glacial period ended between 23,000 and 10,000 years ago.

We are at or beyond the 10,000 year average of the interglacial stage. That leaves me with two questions (science is all about asking questions):

1. Will anthropogenic effects accelerate our decent into the next glacial stage?

2. How fast will the transition to the new glacial age begin? Slow and stready decreasing temperatures over thousands or tens of thousands of years, or will it be like the punctuated events (like the Dansgaard-Oeschger events, Younger Dryas, or 8,200-year event) and happen within our lifetime (~30 years)?

(Notice that one of my questions was NOT "is another ice age likely?" Did the Pope sh*t in the woods? I suppose its possible that anthropogenic effects could cause the Earth to get out of this 2 million year glacial period, but doubtful. The 2 million year problem is probably much grander in scale than greenhouse-gas fluctuations.
 

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here comes trouble
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It's a lot easier to believe the scientists if you're down here in the humidity with consistent 75F days in February (aka the "coldest" month).
 

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jaded bitter joy crusher
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BenWA said:
I think Wally Broecker pioneered the idea that ocean circualation may have a significant effect on global climate.
Broecker did first propose this, but not as a concrete prediction. He introduced the idea at a talk he gave at an AAAS meeting in 1995 in an effort to convince climate theorists to have some humility about their predictions of the effects of global warming. He said that we couldn't rule out anthropogenic climate forcing introducing a new ice age. Since then, careful modeling has pretty much ruled this possibility out, but I think we'd be wise to take Broecker's broader advice on humility.

BenWA said:
1. Will anthropogenic effects accelerate our decent into the next glacial stage?
There is some evidence (most strongly pushed by William Ruddiman) that anthropogenic effects dating back to the dawn of agriculture several thousand years ago have been having a measurable effect of slowing our descent into the next glacial stage. If you look at the Milankovitch paramters, you'll see that the earth's orbital eccentricity is at a local minimum, which would tend to push us into a particularly long glacial stage for the next couple of hundred millennia.

Ruddiman's hypothesis is different from the question of global warming from burning fossil fuels because the amount of greenhouse gases produced by ancient agriculture were much smaller than the amount released by buring fossil fuels (about 90% of the increase in greenhouse gases since the last ice age occurred since 1850 and more than half took place since 1975), but he makes a convincing (to me) case that even the small amounts of greenhouse gases introduced by ancient agriculture had a real effect on climate, and this reinforces the sense that the levels we have introduced in recent times with our industry will have a very dramatic effect over the next few centuries.
 

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I'm not like anyone else
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Gig 'em said:
It's a lot easier to believe the scientists if you're down here in the humidity with consistent 75F days in February (aka the "coldest" month).
Rasberries!!! :p:p:p

32F as we speak with nothing but grey sky and cold dirt.

I'm depressed! :(
 

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here comes trouble
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I'm frustrated because it's too cool to justify turning on the a/c, but warm and humid enough to make it uncomfortable without it. It's good at night, though - 61F right now and I have the windows open with the breeze blowing in off the gulf. The skies turned grey this afternoon, but they were blue this morning when I had to move the old washer and replace it with the new one. That's all I ask.
 

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I'm not like anyone else
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I turned down a transfer a few years ago, when I was a corporate slave, to Bonita Springs. Right now, I'd love to be there. I'm tired of cold and damp with a tiny bit of snow each year. I did it simply because my SO wanted to stay here. Boooohissss! No more SO so it's moot. To be able to open my windows, smell the salty air, and feel 61f air... oh yessss! Tomorrow, it will be 34f as a high.

Don't be frustrated... be happy!

Wanna trade?

Wanna a roomie? ;)

Cheers...
 

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CarbonFrame
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Ft Myers was home for me

everydaybike said:
I turned down a transfer a few years ago, when I was a corporate slave, to Bonita Springs. Right now, I'd love to be there. I'm tired of cold and damp with a tiny bit of snow each year. I did it simply because my SO wanted to stay here. Boooohissss! No more SO so it's moot. To be able to open my windows, smell the salty air, and feel 61f air... oh yessss! Tomorrow, it will be 34f as a high.

Don't be frustrated... be happy!

Wanna trade?

Wanna a roomie? ;)

Cheers...
I used to live in Ft myers untill 2000. I now reside in Minnesota. It was -15 w/ a windchill of -30 yesterday but it will be 20 tomorrow. I'll take the cold over the oppressive June-Oct in Fla. anyday. There are seasons to look forward to here, I enjoy knowing change is on the way.
 

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here comes trouble
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Well I don't particularly want a roomie, but it's my gramma's house so you can take it up with her. ;)
 

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CarbonFrame
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Check it out on the History Channel...

We were talking about this at work recently. My buddy recently saw a show about global warming on the History Channel, It was called "Little Ice Age Big Chill" or "Big Ice Age Little Chill"...anyway it will be airing again in like a week (he said it was interesting).Thought it may be of interest to you guys. I thought I would try to catch it. Most of our studies are based on a couple hundred years of research...Mother earth has been around a bit longer than that.
 
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