Thirty Years On, How Well Do Global Warming Predictions Stand Up?

[late]

It is not me, that is the core of catastrophic AGW, the very heart of the idea of a "tipping point", a point of no return.
What I am saying is that if such a mechanism existed, it would manifest on all earlier warming and cooling as well.

That's just silly.

You're saying the oceans don't buffer, and the research says it does.

 

[longview]

Not in the 70s that I know of.

My understanding is that the secret Big Oil research became public decades later.

Big Oil did not have a secret, CO2 was a known greenhouse gas.
Look up the The Keeling Curve, why do you think Charles Keeling started recording CO2 levels in 1958?
People knew that CO2 could cause some warming, the Science of the day, (as well as currently), says that
the warming from doubling the CO2 level is not of much concern, (roughly 1.1 C over 180 years).
The alarm for AGW was not that CO2 forcing would cause warming, but rather that there existed feedbacks
in the climate system, which would amplify the CO2 warming several times over.

 

[Threegoofs]

It is not me, that is the core of catastrophic AGW, the very heart of the idea of a "tipping point", a point of no return.
What I am saying is that if such a mechanism existed, it would manifest on all earlier warming and cooling as well.
Since the reconstructions do not show these types of feedbacks, why should we believe they will exists in the future?

You really think the science says once a direction has been established, it will never reverse?

You really don’t understand the topic at all.

 

[late]

Big Oil did not have a secret, CO2 was a known greenhouse gas.

They kept their research into AGW secret for decades.

 

[longview]

That's just silly.

You're saying the oceans don't buffer, and the research says it does.

Did I say the oceans don't buffer? I don't think so!
What I said was that in the 2000 year PAGES 2K record, the warming from year 0 to year 600,
would have to have the same amplification factors applied, the output of that amplification cycle,
would then itself be amplified by the same factor, repeating itself every time a cycle period past.
The latency between an input and ECS has been stated to be anywhere between 10 and 120 years or even longer.
More recent work, shows the average ECS lag at 10.1 years, but let's go with 40 years.
If the lag between input and and ECS is 40 years, and the gain is sufficient for the 1.1 C CO2 forced input
to reach an ECS of 3 C (2.7 X), then warming in the first 600 years of the PAGES 2K, would have had many
amplification cycles applied, so many that, we can safely say the gain cannot be that high.

 

[longview]

They kept their research into AGW secret for decades.

If it was "secret" how do you know about it?

 

[longview]

You really think the science says once a direction has been established, it will never reverse?

You really don’t understand the topic at all.

I think when the IPCC AR5 is discussing "tipping points" that is explicitly what they are talking about.
https://www.ipcc.ch/pdf/assessment-report/ar5/syr/SYR_AR5_FINAL_full.pdf

Tipping point
A level of change in system properties beyond which a system reorganizes,
often abruptly, and does not return to the initial state even if the drivers of
the change are abated. For the climate system, it refers to a critical threshold
when global or regional climate changes from one stable state to another
stable state. The tipping point event may be irreversible.
See also Irreversibility. {WGI, II, III}

Now, I do not think such tipping points exists within the limits of our climate system,
and the Marcott et al 2013 reconstruction supports this concept, because if the
high gains existed, they would have amplified earlier warming for many cycles.

 

[Threegoofs]

If it was "secret" how do you know about it?

It’s almost like you never read any of the previous threads you commented on....

 

[Threegoofs]

I think when the IPCC AR5 is discussing "tipping points" that is explicitly what they are talking about.
https://www.ipcc.ch/pdf/assessment-report/ar5/syr/SYR_AR5_FINAL_full.pdf

Now, I do not think such tipping points exists within the limits of our climate system,
and the Marcott et al 2013 reconstruction supports this concept, because if the
high gains existed, they would have amplified earlier warming for many cycles.

So you literally think the consensus of climate science is that anytime a slight rise in temperatures (from whatever cause) will lead to a continuous rise that lasts forever?

Do you even realize the absurdity of your position?

 

[Visbek]

You saying something does not make it true!

You asked me if I was aware of any issue in changing resolutions. I gave you an answer.

And yes, it's true. The different data sets are clearly identified, along with uncertainty levels for the older data, and that is more than sufficient to show that massive spikes are not part of normal variation.

Let's get back to the facts

The facts are that human activity has caused almost all of the warming we've observed in the past ~150 years.

No amount of equivocation on your part changes that.

The climate's response to humans emitting massive amounts of greenhouse gases is higher temperatures. That's not "subjective." Uncertainties about climate response also are not "subjective." I can only conclude that you have no idea what "subjective" means.

We are asked to believe these feedbacks exists at the higher levels, not based on the empirical evidence, but
on wishful thinking.

No, it's based on empirical observations. We determine how much CO2 is in the atmosphere with actual measurements. We know how much CO2 was in the atmosphere previously, and how much the amounts changed, based on actual measurements. We know about permafrost melting at faster rates because of actual research in the field. We know about the presence of soot impacting ice mass losses based on research. We don't know if the Larsen C ice shelf will break up entirely (hence some uncertainty), but we do know based on empirical observations that it can happen, and we can reasonably estimate the effects of such a collapse.

We don't know everything, but what we do know is based on observations and research; and we are increasing our knowledge, and developing better estimates of effects and feedbacks.

The IPCC itself knows better that to drive a stake in the ground that can be shown to be in error,
and so wisely defines a broad range, with the low end close to the CO2 forcing range.

:roll:

The IPCC is very clear on its position. At least half of the uncertainty is because we aren't sure of climate response. However, at least half (if not more) of the uncertainty is because we don't know what human beings will do. I.e. much of that "broad range" is because humans are unpredictable.

What you seem to somehow ignore is that even if the effects of climate variability are low, there will STILL be devastating impacts on the environment and organisms, including humans. Even if some of the worst case scenarios don't happen until 2025 or 2030, it's coming, and we are already seeing some of the damage: More intense storms, more droughts, more floods, more heat waves, higher sea levels, dangerous cold snaps, and more. Again, the nonsense you spin does not change that fundamental fact.

 

[longview]

So you literally think the consensus of climate science is that anytime a slight rise in temperatures (from whatever cause) will lead to a continuous rise that lasts forever?

Do you even realize the absurdity of your position?

Do you understand that when you say that doubling the CO2 level will lead to a likely ECS of 3 C, (and you have said this)
that your statement includes the concept that a slight rise in temperature will be amplified
from the Forcing warming of 1.1 C to the ECS warming of 3 C, after a latency period.
If such an amplification factor exists, it would also exist for the 3 C ECS,
resulting from the first amplification cycle.

What I think is that the consensus of climate science is that CO2 is a greenhouse gas only,
and is not inclusive of the high levels of feedback necessary to make a 1.1 C input into a 3 C ECS output.
Many Scientist likely think there is some positive feedbacks,
but the level of those feedbacks cannot be high enough for an ECS of 3 C.
To assume that a climate amplifier exists, but this amplifier somehow knows to only amplify selected inputs,
is not dealing in reality. Said amplifier would amplify all warming inputs!

 

[longview]

The facts are that human activity has caused almost all of the warming we've observed in the past ~150 years.

No amount of equivocation on your part changes that.

The climate's response to humans emitting massive amounts of greenhouse gases is higher temperatures. That's not "subjective." Uncertainties about climate response also are not "subjective." I can only conclude that you have no idea what "subjective" means.



No, it's based on empirical observations. We determine how much CO2 is in the atmosphere with actual measurements. We know how much CO2 was in the atmosphere previously, and how much the amounts changed, based on actual measurements. We know about permafrost melting at faster rates because of actual research in the field. We know about the presence of soot impacting ice mass losses based on research. We don't know if the Larsen C ice shelf will break up entirely (hence some uncertainty), but we do know based on empirical observations that it can happen, and we can reasonably estimate the effects of such a collapse.

We don't know everything, but what we do know is based on observations and research; and we are increasing our knowledge, and developing better estimates of effects and feedbacks.


The IPCC is very clear on its position. At least half of the uncertainty is because we aren't sure of climate response. However, at least half (if not more) of the uncertainty is because we don't know what human beings will do. I.e. much of that "broad range" is because humans are unpredictable.

What you seem to somehow ignore is that even if the effects of climate variability are low, there will STILL be devastating impacts on the environment and organisms, including humans. Even if some of the worst case scenarios don't happen until 2025 or 2030, it's coming, and we are already seeing some of the damage: More intense storms, more droughts, more floods, more heat waves, higher sea levels, dangerous cold snaps, and more. Again, the nonsense you spin does not change that fundamental fact.

Have I stated that most of the warming in the last 150 is not from Human activity?
It could be, but based on the accepted forcing numbers for CO2 Humans have cause more than half of the observed warming.
Actually the uncertainty in the range of ECS, has nothing to do with what Humans will do,
it is based on doubling the CO2 level.
Form Baede et al 2001 IPCC TAR,

If the amount of carbon dioxide were doubled instantaneously,
with everything else remaining the same, the outgoing infrared
radiation would be reduced by about 4 Wm-2. In other words, the
radiative forcing corresponding to a doubling of the CO2 concentration
would be 4 Wm-2. To counteract this imbalance, the
temperature of the surface-troposphere system would have to
increase by 1.2°C (with an accuracy of ±10%), in the absence of
other changes. In reality, due to feedbacks, the response of the
climate system is much more complex. It is believed that the
overall effect of the feedbacks amplifies the temperature increase to 1.5 to 4.5°C.
A significant part of this uncertainty range arises from our limited knowledge
of clouds and their interactions with radiation.

Yep, no mention of how fast Humans will increase the CO2 level, it is a result of a one time step increase.

 

[Threegoofs]

Do you understand that when you say that doubling the CO2 level will lead to a likely ECS of 3 C, (and you have said this)
that your statement includes the concept that a slight rise in temperature will be amplified
from the Forcing warming of 1.1 C to the ECS warming of 3 C, after a latency period.
If such an amplification factor exists, it would also exist for the 3 C ECS,
resulting from the first amplification cycle.

What I think is that the consensus of climate science is that CO2 is a greenhouse gas only,
and is not inclusive of the high levels of feedback necessary to make a 1.1 C input into a 3 C ECS output.
Many Scientist likely think there is some positive feedbacks,
but the level of those feedbacks cannot be high enough for an ECS of 3 C.
To assume that a climate amplifier exists, but this amplifier somehow knows to only amplify selected inputs,
is not dealing in reality. Said amplifier would amplify all warming inputs!

Once again this comes in handy:

 

[longview]

Once again this comes in handy:

You should really improve on you null responses, they are getting predictable!

 

[Visbek]

Have I stated that most of the warming in the last 150 is not from Human activity?
It could be, but based on the accepted forcing numbers for CO2 Humans have cause more than half of the observed warming.

I pointed you to an article which claims that human activity is likely responsible for 75% of warming.

You fought me on it, proclaiming "We actually do not know what earth's temperature would be without Human activity" (post 109), blathering on about feedbacks, denying the validity of proxy records, and denying the language of the consensus view. Weak.

Actually the uncertainty in the range of ECS, has nothing to do with what Humans will do,
it is based on doubling the CO2 level.

Actually the uncertainty around projected temperatures is a little more than 50% based in what humans will do. "Emission uncertainty" refers to how much greenhouse gases humans are likely to emit.

 

[Visbek]

Many Scientist likely think there is some positive feedbacks,
but the level of those feedbacks cannot be high enough for an ECS of 3 C.

sigh

IPCC AR5:
2.2.5 Climate system responses
Climate system properties that determine the response to external
forcing have been estimated both from climate models and from analysis
of past and recent climate change. The equilibrium climate sensitivity
(ECS)3325 is likely in the range 1.5°C to 4.5°C, extremely unlikely
less than 1°C, and very unlikely greater than 6°C. {WGI SPM D.2, TS
TFE.6, 10.8.1, 10.8.2, 12.5.4, Box 12.2}

You were saying?

 

[longview]

I pointed you to an article which claims that human activity is likely responsible for 75% of warming.

You fought me on it, proclaiming "We actually do not know what earth's temperature would be without Human activity" (post 109), blathering on about feedbacks, denying the validity of proxy records, and denying the language of the consensus view. Weak.



Actually the uncertainty around projected temperatures is a little more than 50% based in what humans will do. "Emission uncertainty" refers to how much greenhouse gases humans are likely to emit.

View attachment 67235645

You seem to not grasp that saying something is "likely" is not the same as saying something "is".
There is uncertainty about Human emissions in the future, but that is not the same uncertainty related to ECS.
The future human emission is related to when the ECS temperature will occur, not how much it will be.
Also I am not blathering about the feedbacks, if they are present at the levels necessary for the 1.1 C
forcing warming to become 3 C of ECS, they would be present and amplifying any outer warming present,
including the 3 C of ECS results.

 

[Surface Detail]

You seem to not grasp that saying something is "likely" is not the same as saying something "is".
There is uncertainty about Human emissions in the future, but that is not the same uncertainty related to ECS.
The future human emission is related to when the ECS temperature will occur, not how much it will be.
Also I am not blathering about the feedbacks, if they are present at the levels necessary for the 1.1 C
forcing warming to become 3 C of ECS, they would be present and amplifying any outer warming present,
including the 3 C of ECS results.

The 3 C of warming is the final outcome of amplification. You are still confusing gain with feedback factor.

Just reflect for a moment on the absurdity of your position. You seem to be saying that feedback can only result in either minimal amplification or infinite amplification. Does this really seem at all plausible to you?

 

[longview]

sigh

IPCC AR5:
2.2.5 Climate system responses
Climate system properties that determine the response to external
forcing have been estimated both from climate models and from analysis
of past and recent climate change. The equilibrium climate sensitivity
(ECS)3325 is likely in the range 1.5°C to 4.5°C, extremely unlikely
less than 1°C, and very unlikely greater than 6°C. {WGI SPM D.2, TS
TFE.6, 10.8.1, 10.8.2, 12.5.4, Box 12.2}

You were saying?

That is what I am saying, that when people say there is a consensus, the consensus is not
the 3 C, but rather that likely ECS is a broad range.
Since the forcing warming is likely about 1.1 C then it is very unlikely that ECS would be less than 1 C,
as that would imply some sort of atmospheric attenuation.

 

[late]

If it was "secret" how do you know about it?

https://www.scientificamerican.com/article/exxon-knew-about-climate-change-almost-40-years-ago/

 

[longview]

The 3 C of warming is the final outcome of amplification. You are still confusing gain with feedback factor.

Just reflect for a moment on the absurdity of your position. You seem to be saying that feedback can only result in either minimal amplification or infinite amplification. Does this really seem at all plausible to you?

Nope, it does not matter what you call it, if the climate amplifier produces a 3 C output for a 1.1 C input,
then you must multiply the input times 2.7 to arrive at that output.
What mechanism is in place that would then stop the 3 C ECS from being the input to the next cycle of amplification?
You say that 3 C of warming is the final outcome of amplification, yet you also say the system contains feedbacks,
why would the 3 C itself not be part of the feedback?
Just reflect for a moment on the absurdity of your position.

 

[longview]

https://www.scientificamerican.com/article/exxon-knew-about-climate-change-almost-40-years-ago/

There were people at Exxon who raise concerns, but they were no more certain then than they are now
about the accuracy of what ECS would be.
By the way the National Academy of Sciences, Charney report in 1979 had the same 1.5 to 4.5 C ECS range we use today.
Last time I checked 1979 was just 2 years after 1977, so much for Scientific American's Exxon knew something 11 years early.
No, people knew CO2 was a greenhouse gas, and some people suspected it might do more than the simple forcing,
but here we are 39 years and billions of dollars after the Charney report, still not closer to how sensitivity the climate is to added CO2.
If you want to look for conspiracies, perhaps you should look at how all that money was wasted?

 

[Surface Detail]

Nope, it does not matter what you call it, if the climate amplifier produces a 3 C output for a 1.1 C input,
then you must multiply the input times 2.7 to arrive at that output.
What mechanism is in place that would then stop the 3 C ECS from being the input to the next cycle of amplification?
You say that 3 C of warming is the final outcome of amplification, yet you also say the system contains feedbacks,
why would the 3 C itself not be part of the feedback?
Just reflect for a moment on the absurdity of your position.

As I point out on the other thread, the input is not 1.1 C; it is a forcing that would eventually result in 1.1 C of warming if there were no feedbacks present.

 

[Tim the plumber]

The 3 C of warming is the final outcome of amplification. You are still confusing gain with feedback factor.

Just reflect for a moment on the absurdity of your position. You seem to be saying that feedback can only result in either minimal amplification or infinite amplification. Does this really seem at all plausible to you?

Originally Posted by longview View Post

Nope, it does not matter what you call it, if the climate amplifier produces a 3 C output for a 1.1 C input,
then you must multiply the input times 2.7 to arrive at that output.
What mechanism is in place that would then stop the 3 C ECS from being the input to the next cycle of amplification?
You say that 3 C of warming is the final outcome of amplification, yet you also say the system contains feedbacks,
why would the 3 C itself not be part of the feedback?
Just reflect for a moment on the absurdity of your position.

Perhaps I can put it in simple terms. Longview, please tell me if this is not the idea you are getting at;

If you have a microphone and speaker, the closer the mic is to the speaker the higher the chance of feedback. If the mic is too close and the input high the the slightest sound causes the high piched wine of feedback that has reached the max the speakers can put out. (Feedback greather than 1)

If the mic is away from the speaker then there is no feed back. (feeback <1)

If the mic is in the zone of potential feedback where all is quiet untill somebody speaks into the mic then if the effect of speaking is that you get a short feedback effect the feedback multiplier is less than 1 still but close to it.

If the effect of speaking causes the set up to go into continious wine mode it was above 1.

If the climate feedback from some input warming is over 1 we would already be Venus II. Thus it must be less than 1.

So a warming due to CO2 of 1.1c cannot cause more than another 1.1c of warming because that would have already fried us.

It can cause any range of warming below that. And obviously it must be distinctly below 1 or the swings in climate would be very very very dramatic.

 

[Surface Detail]

Perhaps I can put it in simple terms. Longview, please tell me if this is not the idea you are getting at;

If you have a microphone and speaker, the closer the mic is to the speaker the higher the chance of feedback. If the mic is too close and the input high the the slightest sound causes the high piched wine of feedback that has reached the max the speakers can put out. (Feedback greather than 1)

If the mic is away from the speaker then there is no feed back. (feeback <1)

If the mic is in the zone of potential feedback where all is quiet untill somebody speaks into the mic then if the effect of speaking is that you get a short feedback effect the feedback multiplier is less than 1 still but close to it.

If the effect of speaking causes the set up to go into continious wine mode it was above 1.

If the climate feedback from some input warming is over 1 we would already be Venus II. Thus it must be less than 1.

So a warming due to CO2 of 1.1c cannot cause more than another 1.1c of warming because that would have already fried us.

It can cause any range of warming below that. And obviously it must be distinctly below 1 or the swings in climate would be very very very dramatic.

As I point out in the "science facts" thread, a gain of 0.63 will give a feedback factor of 2.7, thus amplifying a 1.1 C rise to 3 C. This does indeed produce dramatic swings in climate (cf. ice ages) but not runaway warming, which would require a gain >= 1.