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samwik Offline OP
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The Natural Cooling part:

The orbital (or Milankovitch) changes, which are linked to the switch between glacial and interglacial conditions,
are shown in this graph (note 'zero' Time, in the 'middle'):



After a peak in heating, at 11,000 years ago, most of the COOLING from this cycle has bottomed out; and over the coming millennia it will continue cycling around its average.
===

But the temperatures have been relatively level, as shown by the colored line below, instead of cooling and following the ‘orbital cycle curve’ as might be expected. [“The last 8,000 years have not cooled (moderately) as Milankovitch alone would have suggested.” -https://www.cabrillo.edu/]


===

A “warming force,” which offsets the cooling influence of the orbital change (graphed above), can be found by looking at greenhouse gas changes.


===

The Human Influence part:

...from an article in: New Scientist, 11 December 2003 by Robert Adler
Quote:
http://www.newscientist.com/article/dn4464-early-farmers-warmed-earths-climate.html#.U-jEBfldWSo

“During the previous three periods between ice ages, levels of carbon dioxide and methane in the air fell in lockstep with decreases in summer sunshine caused by cyclical changes in Earth's orbit. But after the most recent ice age, which peaked about 12,000 years ago, the two gases broke the pattern (see graphic [above]).”

“Our tampering with Earth's climate did not begin just a few decades or centuries ago, but 8000 years before, with the birth of agriculture. This controversial theory drastically widens the debate about the timing and extent of humans' impact on the Earth.”

There could easily be other sources for these greenhouse gases; but whatever their source, their greenhouse-heating effects are well documented.
And those heating effects have offset the cooling ‘orbital’ trend, maintaining a level slope for the resulting ‘global temperature’ curve.

Specifically, that would be 'offsetting' to maintain a 'level slope’ during the “Pre-Industrial” era,
as shown in this graphic for “human impact on climate.”


The problem of course, is the nearly-vertical line of the “Industrial-Era Impact” shown for the recent human influence on climate.
===

We are now drastically over-compensating (in red, below) for the natural global cooling; and enough so to change the ‘level slope’ of climate,
upon which our civilization has depended for millennia.


http://www.nature.com/scientificamerican/journal/v292/n3/full/scientificamerican0305-46.html
Scientific American 292, p.46-53 (2005)

Notably, this ‘level slope,’ or the “actual trend” shown above, includes the Roman Warm Period, the Dark Ages,
The Medieval Warm Period, and the Little Ice Age;
but those historical ‘variations’ of average climate are practically unnoticeable at these large scales,
covering thousands to hundreds of thousands of years,
which show climate’s usual variability and the huge range of past (and potential) climate changes.

~


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.
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sam

it looks like your picking up on a few of the things
I have been saying and I can agree with almost all of
your post , except this part

Quote:
We are now drastically over-compensating (in red, below) for the natural global cooling


because we are not compensating enough and this is shown
in the below image.




we need to allow more methane to escape our greedy paws
so that the methane will go into the atmosphere and not
get burned up making energy this way the methane will
help to stall the ice age...

also , could you provide a link to the page where you found
this image?



I tried to find the image by the properties of the image
but I couldn't find it on the web site.

I wanted to read about how the image was produced.










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samwik Offline OP
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Paul, that 'orbital' graphic you asked about came from: Cabrillo.edu/Ruddiman
http://www.cabrillo.edu/~rnolthenius/climate/Denialists/D-Ruddiman/index.html

...but to your main point:
Originally Posted By: paul
...it looks like your picking up on a few of the things
I have been saying and I can agree with almost all of
your post , except this part
Quote:
We are now drastically over-compensating
(in red color, below) for the natural global cooling

because we are not compensating enough and this is shown
in the below image
.



If you lived in Vostok, in East Antarctica, then you might worry about global cooling,
because that graph above (colored, pink/magenta line) is for Vostok temperatures.

And as predicted, East Antarctica is cooling ...during the initial stages of a global warming event. But as a long-term proxy for global temperature ranges and temperature changes, it is a very handy, albeit rough estimate.

The main point was to illustrate how temperatures are not following the Milankovitch forcing anymore; and while Vostok might show a cooling 'trend' over thousands of years, the Vostok temperatures are still fairly ‘flat’ compared to what you’d expect, based upon past behavior.

And do you think the most recent century shows up on those huge ice-core records? You’ve seen plenty of high-resolution charts for the past 10,000 years, and the past 1 to 2 thousand years, which show an even more (relatively) ‘flat’ or level slope/trend for global temperatures, such as:

...a magnified view of (a different version of) that last quarter inch you're talking about.
===

But if you can see how this mechanism,
in which slowly increasing levels of GHGs offset the Milankovitch cooling trend
...to produce a relatively level temperature trend;
can you also see how a large pulse of GHGs would upset that balance?
===

And, if a large pulse of GHGs rapidly initiated this current interglacial,
by raising temperatures by about 10 °F,
then why wouldn’t a similar pulse of GHGs cause a similar rise in temperatures
...as the ensuing decades permit adjustments?

...especially since any cooling cycles will end soon enough, and go on returning to their average;
while the GHGs accumulate, persist, and continue to add more heating force.

~


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Quote:
If you lived in Vostok, in East Antarctica, then you might worry about global cooling,
because that graph above (colored, pink/magenta line) is for Vostok temperatures.


but were talking about global temperature not local
temperatures , the vostok ice core data can be used
to help determine future global temperatures , so no
matter where you live you will be affected by lowering sea
levels and lowering temperatures in a multitude of ways.


Quote:
can you also see how a large pulse of GHGs would upset that balance?


but was the large pulse a pulse of CO2?

not according to todays levels of CO2 and temperatures.

Quote:
...especially since any cooling cycles will end soon enough,


were not seeing any reason to believe that the current cooling
cycle will end soon.

our climate doesn't seem to follow solar insulation as you
have noted , and certainly it will not be CO2 that will end the cooling cycle because we are now seeing
that CO2 does not warm the climate , it could only be
methane as far as Im concerned.

CO2 in the atmosphere is a mechanism of cooling.

where methane in the atmosphere is a mechanism of warming.

if you were charged with finding a process to control
global temperatures would your choice be to
increase methane or to decrease CO2?

and which proofs would you use to determine the reasons for
your choice?









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samwik Offline OP
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Originally Posted By: paul
Quote:
can you also see how a large pulse of GHGs would upset that balance?

but was the large pulse a pulse of CO2?

not according to todays levels of CO2 and temperatures.

Quote:
...especially since any cooling cycles will end soon enough,


were not seeing any reason to believe that the current cooling
cycle will end soon.

our climate doesn't seem to follow solar insulation as you
have noted , and certainly it will not be CO2 that will end the cooling cycle because we are now seeing
that CO2 does not warm the climate , it could only be
methane as far as Im concerned.

CO2 in the atmosphere is a mechanism of cooling.
where methane in the atmosphere is a mechanism of warming.

if you were charged with finding a process to control
global temperatures would your choice be to
increase methane or to decrease CO2?

and which proofs would you use to determine the reasons for
your choice?


Paul, I’m going to stick with the mainstream science (especially for the physics of CO2); so your question (about CO2 being a greenhouse gas or not) should be in a different topic, which you could start. Those claims about CO2 are extraordinary; so I’d expect to have heard more about it, if it were mainstream.
Where did you hear about CO2 operating so differently from CH4 (methane)?
===

But we could still assume it was methane that helped end the cold phase, about 10,000 years ago.
Because within a few decades, or centuries at most, all of that methane would have oxidized into CO2 anyway; so that would still explain why CO2 levels rose by about 100 ppm [180 to 280-ish] during the “rapid” warming, at the start of this interglacial.
===

Changes to Insolation, which come from orbital (Milankovitch) variations, will still add “forcing” to the earth/climate system;
but the greenhouse gases (GHGs), which had 'evenly offset' the natural (orbital) cooling trend, are now expected
to overwhelm that orbital forcing by more than an order of magnitude

...for centuries and millennia to come
...NOT cycling back, and NOT hovering, around some long-standing average ...as do other forcers.
===

Moderate changes in GHG levels were enough to offset the natural cooling cycle
...and give us a 'level' climate, for a few millennia now:


...but the above graph only records up through “pre-industrial” levels
...before the “famous” spike.
===

But look below at the same basic information on the GHGs, which now appears flatter (for the same time period as above)
...because this graph is scaled to include today’s, "before 2005" levels, with the famous spike.
...there is much more 'offset' forcing, by GHGs, recently!

I’d be skeptical of the suggestion that something will prevent
this relatively huge and rapid spike in GHGs from changing the climate
...at least as much as it did during the previous shifts from glacial to interglacial conditions
...but upward now, even more ...and more rapidly too.

~ wink


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sam

it would be nice if the below graph would have extended back a few more thousand years so that a better picture of the timing of the two gasses could be observed in the images.

ie... apx 14,000 yr ago

from what I can tell in the image CO2 also follows methane
ie...
apx 7,800 yr ago CO2 was in a down turn along with methane
then there was a fast upturn of methane , then CO2 slowly began its following of methane as shown in the image.

and at 5,000 yr ago we see a up turn in methane while we dont really notice any change in the CO2 as it is steadily increasing , as you stated it takes longer for the CO2 to
dissipate out of the atmosphere than it does methane.

this is why there is no extreme graphical representation
like in the methane image , the CO2 gas lingers.




I would like to see the above image in a 3 part overlay
I will say that I believe that in the overlay the timing
would be as follows.

1st) methane increase (methane release clathrates , sea level drop ?)
2nd) temperature increase (Methane , apx 24 times GHG as CO2)
3rd) CO2 increase. (increase in life , warmer climate , oxydized methane)



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http://www.laboratoryequipment.com/news/...20&type=cta

Might make an interesting contribution to the ongoing discussion.


There never was nothing.
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earlier when I read the article
I mistook ice sheet for ice shelf and wrote a reply to that
effect ... LOL

I deleted the reply

anyway , the article does mention a few things like soot
and local changes in land use that could contribute to the melting

Quote:
Scientists fault global warming from the burning of coal, oil and gas as well as changes in land use near glaciers and soot pollution. Glaciers in Alaska and the Alps in general have more human-caused melting than the global average, Marzeion said.


but it doesn't mention temperatures as being involved , let me
check that again... nope just global warming.

Quote:
Scientists aren't quite certain what natural causes started glaciers shrinking after the end of the Little Ice Age in the middle of the 19th century,


Quote:
The study showed that it took time for global warming and other factors to build up and cause melting. That lag effect means the world is already locked into more rapid melting from the warming that has already occurred, Marzeion and Alley said.


if temperatures aren't rising , then what could be causing
the melting?

any guesses?



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samwik Offline OP
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Originally Posted By: paul
if temperatures aren't rising,
then what could be causing the melting?

any guesses?
Paul, you're confusing heat with temperature
(...or confusing the total system heating ...with air temperatures).

...the answer is in your article (Bill S's link above): "Study Blames Humans for Melting Glaciers"

Originally Posted By: published in Science Magazine
Over the last two decades, about 295 billion tons (269 billion metric tons) of ice is melting each year on average because of human causes and about 130 billion tons (121 million metric tons) a year are melting because of natural causes, Marzeion calculated.

Glaciers alone add to about four-tenths of an inch of sea level rise every decade, along with even bigger increases from melting ice sheets — which are different than glaciers — and the expansion of water with warmer temperatures.


Plenty of extra heating goes into melting all of that ice, and expanding all of those oceans.

~ wink


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so you are in agreement that temperatures are not causing the
melting then , that's fine with me.

its the soot and the land use etc ... that's causing the melting
... ( human causes other than CO2 ).

I can agree with that also.

all this time I was under the impression that you believed
that rising temperatures due to the increase in CO2 levels
in the atmosphere was causing the melting of ice.

I can agree that more ice is melting , I just cant agree that
a rise in temperatures is causing the melting.

because there isn't any rise in temperatures.

so do we now start a cap n trade of soot and land use program?

LOL






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samwik Offline OP
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...unless you think the terms "global warming" and "climate change" mean something different, in this article....
Originally Posted By: paul
so you are in agreement that temperatures are not causing the melting then , that's fine with me.

its the soot and the land use etc ... that's causing the melting
... ( human causes other than CO2 ).

I can agree with that also.
No Paul... extra heat causes more melting, increased temperatures, AND expansion of oceans;
but NOT all perfectly uniformly, in such a complex system as our biogeochemosphere.

That is why scientist expected (back in 1991)* significant
"variance due to these natural fluctuations ...of climate
on decadal to centennial time scales.
" --*
*Oxford Monographs on Geology and Geophysics no.16; Paleoclimatology; Crowley & North; 1991, (page 257).

...in addition to the human induced changes on climate, such as aerosols, CO2, and other greenhouse gases.
===

Re-read the article; they mention three factors!

"Scientists ...do know what are human-causes:
climate change, soot, and local changes in land use."

It's nice you now understand how
"as well ...changes in land use near glaciers and soot pollution"
are two parts of the larger problem.
===

But of those three causes ("global warming
...as well as changes in land use
near glaciers and soot pollution") quoted from your (Bill S's) article:


The article clearly states
:

"...climate change is the biggest factor, said Ted Scambos, a scientist at the National Snow and Ice Data Center."

~


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sam

you don't need to yell at me (caps and bold letters ), your post are looking more and more like a rant than a discussion.

plus , all of this beating around the bush about the local
heating around glaciers and soot is looking a little like
nit picking to me and probably others who are following the
thread.

from what I can tell theres nothing global about the heating , and there aren't any global temperature rises.

even when you take all of the causes that you may concern
yourself with and add them in the pot and stir the pot we
only see global temperatures decreasing.

what I cant seem to understand is why do people continue to
focus on the tiny amounts of local heating as the article
discusses , and avoid the clear and present dangers of the
serious threats to our climate , namely global cooling.

here is a page that displays some of the effects of global
warming.

and here are a few of the topics.

There has been no measurable atmospheric global warming for almost 18 years.

Total global polar sea ice is largely unchanged over the past 35 years. Antarctic sea ice set all time record for size in September 2013!!

Ocean temperatures are not warming

Sea level has been rising for the past 20,000 years, the rate is not increasing.

Global storms and their energy are in decline

Polar Bear populations are of record size.

Solar energy is in decline. This has led to cooler temperatures in the past

There is no consensus of scientists in support of the man made global warming theory.

Cooling temperatures around the globe


http://isthereglobalcooling.com/

Quote:
Is a carbon cap and trade system that would raise hundreds of billions of dollars each year for the government necessary if in fact the slightly warmer temperatures of 1978-1998 were caused by natural forces such as the Sun's increased activity in that period, and that many scientists are now becoming skeptical of the theory of man made global warming (AGW)? Is the re-engineering of society to reduce CO2 emissions necessary when in the geological history of the planet warming temperatures were never preceeded by rising CO2 levels? Did you know that if this country eliminates 100% of its CO2 emissions China will replace it within in 2 years due to their high growth rate? It appears to me that the man made global warming theory is looking more and more like the Y2K scare of the late 1990s. Perhaps we are seeing a Climate-Industrial Complex.






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Just to add a little local colour, have a look at Tibet.

http://www.nature.com/news/double-threat-for-tibet-1.15738?WT.ec_id=NATURE-20140821


There never was nothing.

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