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Old 06-15-2019, 10:31 PM
 
Location: Missouri, USA
4,347 posts, read 2,974,590 times
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Quote:
Originally Posted by Mircea View Post
Aren't you putting the chicken before the egg? Your view's a bit ethnocentric.

A better question is, "Why do Glacial Periods end?"

This is normal Earth:





That's what Earth is like 80% of time.


The cause of the current Ice Age is pretty clear. The Strait between North America and South America closed with tectonic action creating the Panamanian Isthmus.

At roughly the same time, the Antarctic Continent began sliding into the Antarctic Region.

This Ice Age will last until a substantial part of Antarctica moves out of the South Polar Region. I thought its movement rate was 1.5-2.0 cm per year, not that it matters, since it's not going to happen in our life-times, and humans may not even be around by the time it does.

The scientific evidence shows Glacial Periods lasted 40,000-42,000 years and Inter-Glacials 12,000-15,000 years until the Mid-Pleistocene Event 600,000 years ago which resulted in Glacial Periods lasting 80,000-120,000 years and Inter-Glacials 12,000-30,000 years.

This Inter-Glacial could end tomorrow, or 18,000 years from now.

The fact that Inter-Glacials do end is problematic for the global warming hypothesis.

If the global warming hypothesis had validity, then Inter-Glacials should never end. Earth should continually warm, but that's not what the evidence shows.

Some disingenuously attempt to link Glacial/Inter-Glacial Periods to Milankovitch Cycles, but those fail, too.

The Precession of the Equinoxes which is roughly 25,500 years has a bearing on astronomy and astrology, but not climate.

The 41,000-year axial tilt cycle "appears" to be a causal factor, because pre-Mid-Pleistocene Glacial Periods lasted 40,000-42,000 years, but that's only apparent. When you examine the data, it fails.

If the axial tilt is responsible for Glacial-Periods of 40,000-42,000 years then why aren't Inter-Glacials also 40,000-42,000 years?

Then line up the data, back-to-back Glacials/Inter-Glacials.

You can't claim Earth at its greatest obliquity -- ~21.0° -- causes Glacial Periods, because it doesn't and Earth closest to the vertical -- ~24.5°-- doesn't cause Inter-Glacials. The axial tilt makes no difference, although it might cause minor temperature changes up to 1.0°F.

The 100,000-cycle doesn't play a role, either. 40,000-42,000 years is not 100,000 years any more than 80,000 years to 120,000 years is 100,000 years. If it was 95,000-105,000 years maybe they'd have a point, but that only begs the question "Why now?" and not prior to the Mid-Pleistocene Event.

There's a lot of evidence suggesting that this Inter-Glacial Period began unnaturally, through a cataclysmic event.

That's not to say that we wouldn't be in an Inter-Glacial Period, because we would be, it's just that it would have started 3,000-5,000 years ago instead of 12,000 years ago.

If you look at the map, an Inter-Glacial is very obviously preferable over a Glacial Period.

That map belies the fact that the only arable land is in the equatorial band, between the Tropic of Capricorn and the Tropic of Cancer.

That's not enough to feed 6.5 Billion people.

But none of that matters, because you'll have problems long before anyone ever sees the first glacier.

Look back at the mini-Ice Age and you can see that.

The people in the 100+ New England Colonies were near starvation. They survived only because of imports and the southern Colonies.

The growing season was only 6 weeks. The had from the first week of July to mid-August to prep the field, plant seed, let the crops grow and harvest what they could before the first frost killed everything. In the area that is now between I-80 and I-70 the growing season was only 10 weeks.

In Central Europe, Millions died of starvation. They couldn't grow crops, and the neighboring kingdoms and duchies it was all they could do to feed their own people, so there was nothing to export.

And, you say, "Well, we have tractors and modern farming equipment."

So?

When farmers do a soil test, they take a rod of standard rebar about 1/2" in diameter and hit it once with a 5-lb sledgehammer.

If the rebar goes at least 2" in the soil, they can till, and if it doesn't, they cannot.

If the soil is frozen, it's frozen, and modern tractors with stainless steel plows makes no difference.

Imagine if we had a mini-Ice Age now.
Whelp...I did request no studies or graphs...but that was more regarding simple logical explanations. You, on the other hand, are talking about some pretty big, new pieces of information. I'd appreciate some links, if you have them. If not...I might get around to looking up some of the stuff you mentioned sometime in the next three years or so There's a solid chance it won't happen before 2021. I say that because it'll take me about five to forty times as long to look up information without links.

I appreciate the input anyway.
__________________________________________________ ______________________________

I don't know that cooler average temperatures would be preferable to warmer ones. You can survive basically any temperature colder than it is now...if you have a home. However, there are some levels of heat that just prevent you from being able to work outside. There's only so much you can take off. There's only so much you can sweat before it stops doing you any good.


Researchers calculated the highest tolerable "wet-bulb" temperature — equivalent to what is felt when wet skin is exposed to moving air — and found that this temperature could be exceeded for the first time in human history if*greenhouse gas*emissions continue at their current rate and future climate models are correct. Temperatures this unbearable for humans haven’t been seen during the existence of hominids — the primate family that includes ancient humans — but they did occur about 50 million years ago.
Exposure to wet-bulb temperatures above 95 degrees for six hours or more will create lethal stress levels in humans and other mammals, said study team member Matthew Huber of Purdue University’s earth and atmospheric sciences.
Huber said that while areas of the world regularly see temperatures above 100 degrees, really high wet-bulb temperatures are rare because the*hottest areas of the planet*normally have low humidity — think Arizona’s dry heat. *Areas of the world such as Saudi Arabia have the highest wet-bulb temperatures near the coast where winds occasionally bring extremely hot, humid ocean air over hot land leading to unbearably stifling conditions.

https://www.livescience.com/6428-earth-hot-humans.html

"Wet bulb" temperature has to do with humidity. I'm not sure how humid the atmosphere would have to be to reach the "wet bulb" state they're talking about though.
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Old 06-16-2019, 06:36 AM
 
432 posts, read 561,890 times
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Regarding your initial "logarithmic" question, I would recommend spending some time reading this

http://clivebest.com/blog/?p=1169

The log model is interesting but of course its only one variable as energy trapped on the planet can move between the oceans and atmosphere and the solar input also changes. The sun energy has been apparently dropping https://skepticalscience.com/solar-a...al-warming.htm
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Old 06-16-2019, 07:21 AM
 
Location: Missouri, USA
4,347 posts, read 2,974,590 times
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Quote:
Originally Posted by waltcolorado View Post
Regarding your initial "logarithmic" question, I would recommend spending some time reading this

http://clivebest.com/blog/?p=1169

The log model is interesting but of course its only one variable as energy trapped on the planet can move between the oceans and atmosphere and the solar input also changes. The sun energy has been apparently dropping https://skepticalscience.com/solar-a...al-warming.htm
thanks.
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Old 06-17-2019, 07:42 AM
 
432 posts, read 561,890 times
Reputation: 575
I think you have studied this a fair amount already but I think this is a good video regarding orbital variations and the glacier and inter-glacier periods


https://www.youtube.com/watch?v=Yze1YAz_LYM

If anyone finds some issue with the details, please back it up with a reference..
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Old 06-17-2019, 10:10 AM
 
432 posts, read 561,890 times
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Quote:
I know during interglacial cycles there are high rises of C02 which closely mirror the rise in temperature. What I don't understand is why that comes down again.
I will put link to the discussion on CO2 as both feedback and a driver (or forcing) at the bottom. But one thing to note about CO2 as positive feedback. When temperatures are rising (started by a Milankovitch cycle), the warming causes CO2 to be released from the ocean but with a delay. The positive feedback from CO2 as a greenhouse gas then increases the rate of the temperature rise over what just the solar input alone would have done.

At some point, the solar input peaks and starts to drop. When exactly this happens, I dont think is known but when the temperature finally turns to getting colder from both a reduction in solar energy and reduction in the feedback, the positive feedback aspect of CO2 now accelerates the temperature decrease. Ie, there will be a delay but the cooler oceans now absorb CO2 reducing greenhouse gas and the rate of cooling increases.

I bring this up because Dr. Britt in that video says that we are already past the peak solar of the Milankovith cycle (around 45 minutes into that video). At some point after the peak, we could expect that the planet would begin to cool. As pointed out previously, cooling would be really bad for maintaining the number of people on the planet. He points out that our artificial increases of CO2 (forcing function) has delayed the next glacial period.

I dont know about anyone else but I like the climate on the planet right now and if the video point is correct, we have our nice climate BECAUSE we are doing things to put CO2 (and other greenhouse gasses) into the atmosphere. And.. if this is all correct, when we run out of sources to add CO2 to the atmosphere, its likely to get cold rather quick in geology time scales. My conclusion on this is that going to any other source of energy other than burning fossil fuel is NOT going to save a huge human population from a not so good next phase of the cycle.

The concept of CO2 as both a feedback mechanism and driver (or forcing) is very important to these discussions so here is that link again https://www.yaleclimateconnections.o...limate-system/

Last edited by waltcolorado; 06-17-2019 at 10:22 AM..
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Old 06-18-2019, 08:09 AM
 
432 posts, read 561,890 times
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Quote:
I can think of is that the additional C02 increases plant growth, which absorbs up more C02, which, combined with the effects of Milankovitch cycles,
This link page from Dr Clive Best has a bunch of articles on ice ages

http://clivebest.com/blog/?page_id=6046

Lots of plots and technical stuff - sorry.. (Im not a climate scientist myself so struggle with this also but at least attempt to read and understand).

You could just read all of this. I made a somewhat poor attempt at maybe picking a few articles to start with.

I copied your comment because something similar is discussed regarding life but its low CO2 levels causing plant starvation resulting is dust storms that covered the ice and aided in melting. Generally covered in articles 1 and 5.

Milankovitch cycle.. article 2 and also pretty much every article

Next ice age - articles 6 and 7. Did we dodge the bullet on an ice age pre industrial because of human cause. Next ice age in 12K years or 50K years..
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Old 06-19-2019, 05:05 AM
 
Location: Missouri, USA
4,347 posts, read 2,974,590 times
Reputation: 2027
Quote:
Originally Posted by waltcolorado View Post
I will put link to the discussion on CO2 as both feedback and a driver (or forcing) at the bottom. But one thing to note about CO2 as positive feedback. When temperatures are rising (started by a Milankovitch cycle), the warming causes CO2 to be released from the ocean but with a delay. The positive feedback from CO2 as a greenhouse gas then increases the rate of the temperature rise over what just the solar input alone would have done.

At some point, the solar input peaks and starts to drop. When exactly this happens, I dont think is known but when the temperature finally turns to getting colder from both a reduction in solar energy and reduction in the feedback, the positive feedback aspect of CO2 now accelerates the temperature decrease. Ie, there will be a delay but the cooler oceans now absorb CO2 reducing greenhouse gas and the rate of cooling increases.

I bring this up because Dr. Britt in that video says that we are already past the peak solar of the Milankovith cycle (around 45 minutes into that video). At some point after the peak, we could expect that the planet would begin to cool. As pointed out previously, cooling would be really bad for maintaining the number of people on the planet. He points out that our artificial increases of CO2 (forcing function) has delayed the next glacial period.

I dont know about anyone else but I like the climate on the planet right now and if the video point is correct, we have our nice climate BECAUSE we are doing things to put CO2 (and other greenhouse gasses) into the atmosphere. And.. if this is all correct, when we run out of sources to add CO2 to the atmosphere, its likely to get cold rather quick in geology time scales. My conclusion on this is that going to any other source of energy other than burning fossil fuel is NOT going to save a huge human population from a not so good next phase of the cycle.

The concept of CO2 as both a feedback mechanism and driver (or forcing) is very important to these discussions so here is that link again https://www.yaleclimateconnections.o...limate-system/
I have no problem with the data in the video, but I came to different conclusions about the video's message than you.

Yes...the planet is not unpleasantly cold due to human activity. However, think about how many more people exist now than existed in the past. Note that the video suggested that the past 5,000 years of human activity was a likely cause for Earth not being unpleasantly cold.

Earth is warming now and has been for a long time.

https://earthobservatory.nasa.gov/wo...ge/DecadalTemp

I don't think we need to be worried about our fate two thousand years from now so much as our fate four hundred years from now. If it's warming now, I don't know why it would stop warming at any point when it's relevant to us without a lot of work on the part of humanity.

Yeah...extremely cold temperatures would be bad, but our species' activity has been overwhelming those temperatures for the last 5,000 years even with the miniscule human activity in the past...human activity that involved no cars or planes using fossil fuels. I don't see temperature drops as a significant risk here.

Even if we do run out of C02-producing materials, our livestock can still produce methane. I see global warming as, as much of a problem as I did before watching the video, if not more.

Last edited by Clintone; 06-19-2019 at 05:52 AM..
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Old 06-19-2019, 08:37 AM
 
Location: Somewhere in northern Alabama
17,854 posts, read 54,146,150 times
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"Even if we do run out of C02-producing materials, our livestock can still produce methane. I see global warming as, as much of a problem as I did before watching the video, if not more."

I keep seeing statements like this that are based upon the nightmares of militant vegans and animal rights activists, and I normally just let it pass, but sometimes a reminder is in order.

Short of nuclear reactions, matter is neither created nor destroyed. Cattle are not nuclear reactors. Elements are also ... elements. They do not transmute. You can't get gold from lead and alchemy. If I said that spinach grown with just water and air would supply you with enough iron to create a hammer, you would rightly call me a loony. Spinach doesn't MAKE iron, it has to uptake it from the soil. The same goes for livestock. They don't create any more carbon in products than the amount of carbon that goes into their bodies.

What these rocket science activists don't say is that if the hay eaten by ruminants was simply left in the field to rot, it would turn back into a more or less equal amount of carbon dioxide (more actually, since meat contains carbon), OR if it happened to fall in a protected wetland and land in a swamp, it would turn into methane, with something similar to cow poo left over. Also, methane decomposes in light into CO2 over the span of less than a decade.

The gullibility of the public and lack of basic understanding of conservation of mass and energy always amazes me. Explain it to the activists and give them their proper bumper stickers - BAN GRASS! BAN THE WETLANDS!

Last edited by harry chickpea; 06-19-2019 at 08:45 AM..
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Old 06-19-2019, 08:40 AM
 
432 posts, read 561,890 times
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FYI, good for you (Cintone) for actually studying the science.

I feel these discussion are better when when opinions are left out and everything is backed up with a reference.. but here is my opinion. I may have given you the wrong impression because I completely agree that the planet is warming and that we are at least causing half that warming and likely more. Predictions about the future are of course likely inaccurate because we dont know how humans will influence that and change the parameters but I have bought into believing the short term predictions of worse fire seasons because of higher heat drying things out faster, more flooding and the predicted sea level rise that will mostly occur later in this century.

This discussion was about ice ages which I have found interesting lately and we may have influenced this and possibly could in the future by "engineering" the atmosphere insulation through fossil fuel burning. Interesting idea.. but little hope for that as money is involved and LOTS of money is involved (how big are the oil, gas and coal industries). These discussion are always better when you have to provide a link that agrees with you - somewhat self check. This is just my opinion.. so better stop now.


Global warming.. a discussion that would be interesting is to actually READ the IPCC report and if someone finds an error, back it up with a reference. Or if you think the IPCC is just a political tool, back it up with the reference even if it is from a conservative blog.

https://www.ipcc.ch/

Im going to try and read this report https://www.ipcc.ch/sr15/chapter/sum...policy-makers/
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Old 06-19-2019, 08:56 AM
 
Location: Seattle
626 posts, read 154,926 times
Reputation: 691
Quote:
Originally Posted by harry chickpea View Post
"Even if we do run out of C02-producing materials, our livestock can still produce methane. I see global warming as, as much of a problem as I did before watching the video, if not more."

Short of nuclear reactions, matter is neither created nor destroyed. Cattle are not nuclear reactors. Elements are also ... elements. They do not transmute. You can't get gold from lead and alchemy. If I said that spinach grown with just water and air would supply you with enough iron to create a hammer, you would rightly call me a loony. Spinach doesn't MAKE iron, it has to uptake it from the soil. The same goes for livestock. They don't create any more carbon in products than the amount of carbon that goes into their bodies.
Please note that methane and carbon dioxide are not elements; they are molecules. We can and do generate more of them.
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