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The atmospheric temperature discussed as
dangerous has been common in many parts of
the earth for many years and is not nearly
new. The real threat discussed is from
heavy consideration of
"business-as-usual RCP8.5 emissions
scenario"
and that is based on climate models
evaluating the future, 2050+, effects of
human sources of CO2 on temperature and
climate.
We have a long history of such models.
Apparently they are usually based on the
fact that CO2 is a greenhouse gas.
The main question about CO2 is how much
warming will be caused by a given quantity
of CO2 from human activities.
Yes, CO2 is a greenhouse gas, but maybe
surprisingly so far from either
observations or models, we have no
credible evidence that human sources of
CO2 have caused, are causing, or will
cause significant warming.
Okay, let's look at the observational
data:
There was a movie, An Inconvenient
Truth. With data from Antarctic ice
cores, the movie showed, for the
atmosphere, a graph of temperature and CO2
concentrations going back about 800,000
years.
As I watched the movie, it appeared that
the claim was that the graph showed
temperature and CO2 concentrations going
up and down together. Then the movie
concluded that the higher concentrations
of CO2 caused the higher temperatures.
Then there was a claim that currently more
CO2 from human activities would rapidly
cause significantly higher temperatures.
But, we could look at that graph more
closely, and doing that we will see three
situations:
(1) When temperature started to increase,
CO2 (concentration, here and below) was
low, not high. So, something caused the
warming, but it was not high CO2.
(2) About 800 years later, CO2 had
increased. Presumably the cause was more
biological activity from the higher
temperatures.
(3) Some thousands of years later, while
CO2 was high, the temperatures fell again.
There was a cause, but it was not low CO2.
Indeed, the high CO2 did not keep
temperatures from falling.
Net, from that 800,000 years of data,
there is no evidence that high CO2 caused
high temperatures. It would be more
accurate (though of course still wrong) to
say that the data supported that CO2
caused LOWER temperatures.
For some more recent data, there was some
significant warming during the time of the
Roman Empire and during the Medieval Warm
Period, and there is no evidence that the
cause was high CO2. There was some
significant cooling during the Little Ice
Age from roughly 1300 to 1900, but there
is no evidence that the cause was low CO2.
There was some cooling from 1940 to 1970
and concerns in the media about another
ice age, and those years were when there
was more CO2 from human activity from WWII
and the post-war economic boom. So, in
those years, with more CO2, we got some
cooling instead of warming.
Again it would be more accurate (though of
course still wrong) to say that the data
supported that CO2 caused COOLING.
For some details, can start with "Global
Cooling" at
which discusses the two famous magazine
stories, the 1974 <i>Time</i> story and
the 1975 <i>Newsweek</i> story, worrying
about "global cooling" and asking if we
were entering a new ice age. For more on
these magazine stories, at
can see the April 28, 1975,
<i>Newsweek</i> article “The Cooling
World”.
So, net, there is no data on temperature
and CO2 from the past that says that CO2
will cause warming.
Yes, CO2 is a <i>greenhouse</i> gas. This
means that it absorbs some light in the
infrared but not the visible. In the case
of CO2, it absorbs light out in the
infrared in three narrow bands. The
absorption spectrum is given at
Part of the mechanism is Planck black body
radiation.
We have had some warming since the Little
Ice Age. It may be that we are still
pulling out of the Little Ice Age, e.g.,
it can take a long time for the oceans to
warm up. But even with this warming, it's
cooler than in the Medieval Warm period
and the Roman times when the polar bears
didn't go extinct, the ice in Greenland
and the Antarctic didn't melt, the oceans
didn't rise and flood the coasts, and
apparently humans didn't suffer.
Apparently the main effects were greater
agricultural productivity, e.g., in
England, grapes were grown for wine.
Could the warming since the Little Ice Age
be due to CO2? No: The warming is at the
surface, and CO2 absorbs high in the
troposphere with definition at Google:
<blockquote>the lowest region of the
atmosphere, extending from the earth's
surface to a height of about 3.7–6.2 miles
(6–10 km), which is the lower boundary of
the stratosphere. </blockquote>
which, from MIT climate scientist Richard
Lindzen, Alfred P Sloan Professor of
Atmospheric Sciences, Emeritus, at
Massachusetts Institute of Technology, has
gotten cooler, not warmer.
Several attempts were made to model the
atmosphere and calculate and predict the
effects of human sources of CO2 on
temperature. Nearly all the efforts
predicted temperature increases that were
rapid and significant.
It has now been some years since the times
of the predictions, and the predictions
and reality are compared in the graph at
Summary: Nearly all the predictions were
way too high.
Science: So, so far climate modeling has
no predictive value and, thus, is not good
science.
Result: The predictions have no
meaningful credibility.
Current Summary: There is no credible
evidence from either the 800,000 years of
the earth or the climate models that human
sources of CO2 have had, are having, or
will have significant effects on
temperature or climate.
As a result of this lack of evidence,
there is no scientific reason to attempt
to lower human sources of CO2.
Resolving at least what is in my post is much easier than working through the IPCC's reports:
It's simple, really simple, just as in my post:
Observational data: The main observational data used to argue the dangerous effects of CO2 is just the 800,000 years of ice core data. But just looking at that data, as I explained in fine detail, that data does not support the claimed effects of CO2.
Models. Again as I explained carefully, so far the climate models have been proven wrong by reality and, in particular, have no predictive value and, thus, are not good science.
Net, there is nothing credible in data or models that says human sources of CO2 will cause significant warming.
In particular, the IPCC has no data or models that do better.
If you want to make an argument for being alarmed, I can do better than the IPCC: We don't really know what CO2 will do. In particular we have no data or models that are credible and say that we are safe.
I have shown, in just one simple post, that the alarmists don't have credible evidence. But I have not shown that we are safe.
Now the next real question is, what to do when we don't have any credible evidence that we are safe or not.
"It is unequivocal that human influence has warmed the global climate system since pre-industrial times."
"The likely range of human-induced warming in global-mean surface air temperature (GSAT) in 2010–2019 relative to 1850–1900 is 0.8°C–1.3°C, encompassing the observed warming of 0.9°C–1.2°C, while the change attributable to natural forcings is only −0.1°C–0.1°C."
This is as far as I go to help educate you, as I remain unconvinced any efforts to do more would be helpful.
I have seen that IPCC statement you quoted before and don't regard it as credible.
Again, once again, over again, yet again, one more time, just
from what I wrote, from either data or models, there is no credible evidence that CO2 from human activities has had, is having, or will have a significant effect on temperature.
When there is credible evidence, I will pay close attention.
The IPCC can say "unequivocal" all they want, but that does not make their claims true.
Actually saying "unequivocal" is at best just a qualitative summary and no evidence at all.
So far, no one has any credible evidence that humans are significantly warming the earth, and in particular the IPCC has no such evidence.
If you want to point to where the IPCC has credible evidence, then fine, but just their claiming "unequivocal" means nothing.
But again, so far no one has any such credible evidence; in particular, the IPCC has none, and there is none to point to in their many long documents.
To explain further, the data from the 800,000 years has not changed. Data from just the last 150 years or so is not very much data. The models that have been tested by comparison with reality have nearly all failed. That's where we stand, including the IPCC.
I love how "skeptic249757" think their few hours of google searching is somehow comparable to a massive body of climate researchers that have spend decades digging into the state of our climate. It's like the time my boss told me the lump in my neck was nothing to worry about and I was wasting my time by having a doctor look at it.
But, as they say, you can't reason someone out of a position that didn't reason into in the first place.
The atmospheric temperature discussed as dangerous has been common in many parts of the earth for many years and is not nearly new. The real threat discussed is from heavy consideration of
"business-as-usual RCP8.5 emissions scenario"
and that is based on climate models evaluating the future, 2050+, effects of human sources of CO2 on temperature and climate.
We have a long history of such models. Apparently they are usually based on the fact that CO2 is a greenhouse gas.
The main question about CO2 is how much warming will be caused by a given quantity of CO2 from human activities.
Yes, CO2 is a greenhouse gas, but maybe surprisingly so far from either observations or models, we have no credible evidence that human sources of CO2 have caused, are causing, or will cause significant warming.
Okay, let's look at the observational data:
There was a movie, An Inconvenient Truth. With data from Antarctic ice cores, the movie showed, for the atmosphere, a graph of temperature and CO2 concentrations going back about 800,000 years.
As I watched the movie, it appeared that the claim was that the graph showed temperature and CO2 concentrations going up and down together. Then the movie concluded that the higher concentrations of CO2 caused the higher temperatures. Then there was a claim that currently more CO2 from human activities would rapidly cause significantly higher temperatures.
But, we could look at that graph more closely, and doing that we will see three situations:
(1) When temperature started to increase, CO2 (concentration, here and below) was low, not high. So, something caused the warming, but it was not high CO2.
(2) About 800 years later, CO2 had increased. Presumably the cause was more biological activity from the higher temperatures.
(3) Some thousands of years later, while CO2 was high, the temperatures fell again. There was a cause, but it was not low CO2. Indeed, the high CO2 did not keep temperatures from falling.
Net, from that 800,000 years of data, there is no evidence that high CO2 caused high temperatures. It would be more accurate (though of course still wrong) to say that the data supported that CO2 caused LOWER temperatures.
For some more recent data, there was some significant warming during the time of the Roman Empire and during the Medieval Warm Period, and there is no evidence that the cause was high CO2. There was some significant cooling during the Little Ice Age from roughly 1300 to 1900, but there is no evidence that the cause was low CO2. There was some cooling from 1940 to 1970 and concerns in the media about another ice age, and those years were when there was more CO2 from human activity from WWII and the post-war economic boom. So, in those years, with more CO2, we got some cooling instead of warming.
Again it would be more accurate (though of course still wrong) to say that the data supported that CO2 caused COOLING.
For some details, can start with "Global Cooling" at
https://en.wikipedia.org/wiki/Global_cooling#1974_Time_magaz...
which discusses the two famous magazine stories, the 1974 <i>Time</i> story and the 1975 <i>Newsweek</i> story, worrying about "global cooling" and asking if we were entering a new ice age. For more on these magazine stories, at
https://longreads.com/2017/04/13/in-1975-newsweek-predicted-...
can see the April 28, 1975, <i>Newsweek</i> article “The Cooling World”.
So, net, there is no data on temperature and CO2 from the past that says that CO2 will cause warming.
Yes, CO2 is a <i>greenhouse</i> gas. This means that it absorbs some light in the infrared but not the visible. In the case of CO2, it absorbs light out in the infrared in three narrow bands. The absorption spectrum is given at
https://webbook.nist.gov/cgi/cbook.cgi?Spec=C124389&Index=0&...
Part of the mechanism is Planck black body radiation.
We have had some warming since the Little Ice Age. It may be that we are still pulling out of the Little Ice Age, e.g., it can take a long time for the oceans to warm up. But even with this warming, it's cooler than in the Medieval Warm period and the Roman times when the polar bears didn't go extinct, the ice in Greenland and the Antarctic didn't melt, the oceans didn't rise and flood the coasts, and apparently humans didn't suffer. Apparently the main effects were greater agricultural productivity, e.g., in England, grapes were grown for wine.
Could the warming since the Little Ice Age be due to CO2? No: The warming is at the surface, and CO2 absorbs high in the troposphere with definition at Google:
<blockquote>the lowest region of the atmosphere, extending from the earth's surface to a height of about 3.7–6.2 miles (6–10 km), which is the lower boundary of the stratosphere. </blockquote>
which, from MIT climate scientist Richard Lindzen, Alfred P Sloan Professor of Atmospheric Sciences, Emeritus, at Massachusetts Institute of Technology, has gotten cooler, not warmer.
Several attempts were made to model the atmosphere and calculate and predict the effects of human sources of CO2 on temperature. Nearly all the efforts predicted temperature increases that were rapid and significant.
It has now been some years since the times of the predictions, and the predictions and reality are compared in the graph at
http://www.energyadvocate.com/gc1.jpg
Summary: Nearly all the predictions were way too high.
Science: So, so far climate modeling has no predictive value and, thus, is not good science.
Result: The predictions have no meaningful credibility.
Current Summary: There is no credible evidence from either the 800,000 years of the earth or the climate models that human sources of CO2 have had, are having, or will have significant effects on temperature or climate.
As a result of this lack of evidence, there is no scientific reason to attempt to lower human sources of CO2.