Merged Global Warming Discussion II: Heated Conversation

[Cl1mh4224rd]

I strongly disagree that the numbers in the IPCC report are remotely credible, though. Obviously I'll never persuade the true believers that populate this thread, but just making the statement for the record

We're not the ones you need to convince. Perhaps you should get a paper published...

How can the earth be cooling when the thirteen hottest years since records began have been this century and the last year with average temperatures below the 20th century average was 1976?

We've all been holding our thermometers upside down?

Except that we are seeing cooling now.

It's not cooling like you imagine.

So, not cooling at all then.

 

[aleCcowaN]

It's been a tough summer and fall, there. I hope you enjoyed a hoppy ale or two to celebrate a late fall afternoon/evening,...the sun is still up here and my air conditioner will probably keep running for another few hours yet,...a hoppy ale or two sounds good to me, see you on the morrow.

I took a look at those papers we were talking about yesterday. The last one was one I have read 2 or 3 years ago. Though they deserve a much deeper look, they reminded me some basic elements -like the bicarbonate/carbonate relation and carbonate depletion-. Anyway, as I thought, some massive emissions were assumed for those long lasting scenarios. For instance, making up some quick similar figures for the sake of comparison, the paper may deal with 5000 GT of carbon emissions, with 10% staying a long long time, and some additional 25% staying beyond the third millennium. On the contrary, I was talking about shutting all emissions right now in some posts -leaving some 200 GT of carbon to digest-, and my scenario with hardly going up 550 ppm during this century, with a peak in 40 or 50 years, that is 600 GT of carbon to get rid of. A smaller fraction would remain airborne. I can't estimate how much and when. But from those 1500 GT still going around in the first scenario by year 3000, I expect it to be something between almost 0 and 100 GT in mine, and those are values that leave our atmosphere close to pre-industrial levels, what I was saying.

I was about to write about my experience asking favours and being explained about current models and their runs, but it's too complex and I only went with a few questions and got a few answers -and I am speaking of many hours doing so- together with people taking the time to explain to me a lot of details and the patience to do it and quench my curiosity. It doesn't matter really, because for what matters I could summarize that in: temperature is not going up as much and quick as expected in earlier versions; variability greater than expected, including regional trends; models still not representing a natural earth so uncertainty grows quickly once we go far from present conditions.

What is left is not paper vs paper or paper vs vision. We have to explain why we consider this or that scenario to be true. I can't find any logic in some figures some of you are showing me, as those figures depict scenarios where emission in 2090 are 5 to 10 times the current ones, and they continue to grow at some rate of 2 or 3% a year for some unexplainable technological contemporaneousness ... in 2090!!! I found that to be simply unacceptable.

 

[Trakar]

The ipcc's "slightly conservative" report predicts possibly nearly a 1m sea level rise by the end of the century, coupled with greater storm intensity, increased drought and floods, more extreme heat waves, the effects of ocean acidification etc. IMO most of the posts from people who accept that AGW is a fact reflect that. I would actively encourage you to point out where anyone overstates the likely effect but you seem to be vastly overstating exaggeration of AGW while ignoring the fact that often nearly half of the posts in this forum are from people who get their scientific "facts" either directly or indirectly from the Heartland institute or the GWPF.

Global sea level linked to global temperature
http://www.pnas.org/content/early/2009/12/04/0907765106.full.pdf

...Discussion: Implications for the Future
If our method presents a reasonable approximation of the future sea-level response to global warming, then for a given emission scenario sea level will rise approximately three times as much by 2100 as the projections (excluding rapid ice flow dynamics) of the IPCC AR4 (2) have suggested. Even for the lowest emission scenario (B1), sea-level rise is then likely to be
1 m; for the highest, it may even come closer to 2 m...
(Read rest at link)
Software code accompanying this article is available (SI Sea-Level Code).

 

[Reality Check]

Nah. ..
View attachment 31129

It is a comparison of hindcasts of precipitation by climate models and observations at the globally averaged level across land.

CoolSceptic, you do realize that an unattributed image from a conference is rather dubious ?
What was the presentation?
Who was the author(s)?
What was the context if the image?
Is it in a published paper?
What does "alternative models" in the title suggest to you?
What does the presentation as absolute values rather than anomalies suggest to you? Hint: the models usually produce anomaly graphs.

 

[Trakar]

I took a look at those papers we were talking about yesterday. The last one was one I have read 2 or 3 years ago. Though they deserve a much deeper look, they reminded me some basic elements -like the bicarbonate/carbonate relation and carbonate depletion-. Anyway, as I thought, some massive emissions were assumed for those long lasting scenarios. For instance, making up some quick similar figures for the sake of comparison, the paper may deal with 5000 GT of carbon emissions, with 10% staying a long long time, and some additional 25% staying beyond the third millennium. On the contrary, I was talking about shutting all emissions right now in some posts -leaving some 200 GT of carbon to digest-, and my scenario with hardly going up 550 ppm during this century, with a peak in 40 or 50 years, that is 600 GT of carbon to get rid of. A smaller fraction would remain airborne. I can't estimate how much and when. But from those 1500 GT still going around in the first scenario by year 3000, I expect it to be something between almost 0 and 100 GT in mine, and those are values that leave our atmosphere close to pre-industrial levels, what I was saying.

I was about to write about my experience asking favours and being explained about current models and their runs, but it's too complex and I only went with a few questions and got a few answers -and I am speaking of many hours doing so- together with people taking the time to explain to me a lot of details and the patience to do it and quench my curiosity. It doesn't matter really, because for what matters I could summarize that in: temperature is not going up as much and quick as expected in earlier versions; variability greater than expected, including regional trends; models still not representing a natural earth so uncertainty grows quickly once we go far from present conditions.

What is left is not paper vs paper or paper vs vision. We have to explain why we consider this or that scenario to be true. I can't find any logic in some figures some of you are showing me, as those figures depict scenarios where emission in 2090 are 5 to 10 times the current ones, and they continue to grow at some rate of 2 or 3% a year for some unexplainable technological contemporaneousness ... in 2090!!! I found that to be simply unacceptable.

BAU, I agree unacceptable. I thought reasonable people looking at the evidence would react reasonably and we would have already been actively pulling carbon out of the atmosphere for the last decade. Instead BAU, and no real signs that we are going to veer from that anytime in the next century.
I sincerely hope I am wrong.

So with a magic immediate cessation of human emissions, what volume of CO2 do you see natural processes (mainly the ocean) removing from the atmosphere for each of the first 10 years?

 

[aleCcowaN]

View attachment 31129

Sorry, I didn't read the text, but there's a problem with the image. What is it the black line? Can you point to the database of that line? Don't you have some 1000mm global average land precipitations by 1990? Take a look to this source. Why don't you calculate the value? Take the twenty biggest countries if you are in a rush. Don't forget Antarctica.

 

[lomiller]

Nah. Here's a plot that was shown at the recent European Geosciences Union general assembly (held every year in Vienna, although staggeringly expensive for those of us who don't get paid from the climate science trough to be there):

View attachment 31129

It is a comparison of hindcasts of precipitation by climate models and observations a.

of precipitation, not temperature. Useless for the discussion at hand.

If models can't get the hydrological cycle right - which includes precipitation, cloud cover, water vapour concentrations etc. etc - they stand no hope of getting temperature right, as these things are so important to temperature.

Don't be ridiculous. Calculating top of atmosphere energy balance if a FAR simpler problem than calculating every detail of how that is felt in a complex system.

 

[lomiller]

If the system is linear, then no, increased rates of warming are not more realistic than cooling.

A linear system demands that an increasing rate in the stimulus be reflected in an increasing rate in the response. If the rate if rise in CO2 forcing is increasing the rate of rise in response must also be increasing.

If the system is non-linear, then "positive feedbacks are getting stronger" is pure nonsense.

To be linear a system must obey superposition. In the case of the climate system this means that if the forcing from an increase in Methane would cause a 1 deg C increase in global temperatures, and the forcing form an increase in CO2 would cause a 2 deg C increase in global temperatures the two together would cause a 3 deg increase in global temperatures.

If the positive feedback increases with warming the combination of the two will produce warming of more than 3 deg and the system is therefor not linear.



So while the response to a fixed release of CO2 is not linear the climate response to CO2 forcing can be. While this response actually is not linear, linearity is still a good approximation near the stable norms of the last few thousand years. Unfortunately we are going beyond that and if we go to far we will eventually hit a non-linearity AKA a tipping point.

 

[macdoc]

Originally Posted by aleCcowaN View Post
That post and other few like it are meant to trigger reflection.

Capel
Not working, is it? Your apparent guru complex just puts people's backs up. I say "apparent" because I'm sure it's not real, but I don't think everybody is.

My sense was Alec was away from school and did not have students to beat on

 

[Reality Check]

I've presented many factual arguments here, a few years back.

One fact you have missed out, CoolSceptic, is whether these "factual arguments" exist or not .
No old posts from you "here" in this thread (but it started on 29th June 2013).
Maybe you mean the AGW without HADCRUT3 or some other thread.

 

[Trakar]

of precipitation, not temperature. Useless for the discussion at hand.

Don't be ridiculous. Calculating top of atmosphere energy balance if a FAR simpler problem than calculating every detail of how that is felt in a complex system.

I'd still like to see a source for the graph.

Looking at various studies that examined the particular issue of precipitation and major modern climate models hindcast performance, the results don't look like what has been described, at least in studies such as:

Are climate model simulations useful for forecasting precipitation trends? Hindcast and synthetic-data experiments.
http://iopscience.iop.org/1748-9326/9/2/024009/pdf/1748-9326_9_2_024009.pdf

5. Conclusions
Our hindcast and forecast experiments suggest that climate models have some skill in simulating precipitation change over the next few decades. Given the large regional changes (in many places well in excess of 1 standard deviation) in precipitation seen over the last century, the assumption of
hydrologic stationarity is a suboptimal one for planning even given the limitations of current climate models. Precipitation forecasts could be further improved by addressing model deficiencies or by empirical correction of the simulated spatial patterns of precipitation change.

 

[Trakar]

Sorry, I didn't read the text, but there's a problem with the image. What is it the black line? Can you point to the database of that line? Don't you have some 1000mm global average land precipitations by 1990? Take a look to this source. Why don't you calculate the value? Take the twenty biggest countries if you are in a rush. Don't forget Antarctica.

And why did the graph stop nearly a decade and a half ago, how old is this study?

 

[lomiller]

I'd still like to see a source for the graph.

Looking at various studies that examined the particular issue of precipitation and major modern climate models hindcast performance, the results don't look like what has been described, at least in studies such as:

Are climate model simulations useful for forecasting precipitation trends? Hindcast and synthetic-data experiments.
http://iopscience.iop.org/1748-9326/9/2/024009/pdf/1748-9326_9_2_024009.pdf

It'd be interesting to see the source, but ultimately the ability to predict (regional?) precipitation trends doesn't tell us much if anything about climate models ability to predict global temperature trends. It's still an interesting and important field of research.

 

[Trakar]

I can't find any graph covering the time period of the contentious graph that looks anything like what was presented here. Here is a set precip graphs that cover the period of the graph presented here.

"Global precipitation trends in 1900–2005 from a reconstruction and coupled model simulations"
http://shen.sdsu.edu/pdf/renl_jgrat_2013.pdf

 

[Trakar]

It'd be interesting to see the source, but ultimately the ability to predict (regional?) precipitation trends doesn't tell us much if anything about climate models ability to predict global temperature trends. It's still an interesting and important field of research.

Certainly, conditions are changing, and models are going to have a hard time accurately simulating global conditions that are unlike any we have witnessed since our species' arrival. We have some rough guidelines in more ancient epoch climate systems but in addition to being much slower in their evolution, there are enough other significant differences that, at best, we can really only speak of ranges of possible consequences and rough estimations of time frames.

 

[macdoc]

I think he just grabbed that and concocted something - that's how that site works. Allows tinkering.

His image is based out of here ( always find out the source ) and searching worldwide there is no matching image anywhere. A very useful tool for sourcing
http://www.tineye.com

http://www.climatedata.info/index.html

Which

We provide a model to quantify the effects of climate change. With the model you can:
Work with IPCC SRES climate scenarios
Import climate and other dataAnalyse changes to river flow, runoff, soil moisture, groundwater recharge, snow melt, frost days and irrigation demand
Simulate the impacts anywhere in the world Output the results in a range of graphic formats or as csv files

Recall that Time Magazine cover...

Trak

I can't find any graph covering the time period of the contentious graph that looks anything like what was presented here. Here is a set precip graphs that cover the period of the graph presented here.

What I suggest is he grabbed the graph you have without any attribution and laid some weird hindcasting over it and presented as if it were something out of a conference he was actually at.

I call it horsepucky.

 

[PossumPie]

Not quite. You are confusing positive feedback with system stability. For systems without a time delay element negative feedback enhances stability while positive feedback degrades it. This doesn’t mean positive feedback automatically drives the system to instability. For stable cases positive feedback acts as amplification, it makes smaller signals larger. Negative feedback does the opposite and reduces the response to any change.

Time delays can change everything making negative feedback systems unstable and in some cases even make an otherwise unstable positive feedback system stable. For example let’s say you have a thermostat on the opposite side of the room t your heat source. The room cools so the thermostat kicks in, but it takes time for the heat at one end of the room to reach the thermostat. The heat source keeps warming the room even though most of it is well above the temperature it was supposed to shut off. When it does finally shut off the room is much warmer than it’s supposed to be.

It then starts to cool, but again it takes time for that cooling to reach the side of the room where the thermostat is. Once again the side of the room where the thermostat is located is the last to drop below the threshold temperature and the rest of the room is much colder than it’s supposed to be.

In this example, even though the thermostat is configured to oppose any change in room temperature (negative feedback) the system itself is unstable so the room temperature swings wildly from hot – cold – hot.

Thank you for the clarification. Even in the example you gave however, the wild temperature fluctuation would remain within constraints, the negative feedback loop would just have wider amplitude. Or am I still missing something?

 

[aleCcowaN]

So with a magic immediate cessation of human emissions, what volume of CO2 do you see natural processes (mainly the ocean) removing from the atmosphere for each of the first 10 years?

Pressed to reply without doing any search or calculation, I would say 10 to 13 ppmv CO2 down at Mauna Loa for the first decade, depending on the global temperatures. Very old models (old like a 486 or a Pentium I) had a fixed ratio of ocean absorption and neutral land vegetation so they showed much less. Of course, we knew less then and CO2 levels were around 350.

 

[aleCcowaN]

And why did the graph stop nearly a decade and a half ago, how old is this study?

Oooh! Don't worry, I've got a lot more in the cartridge only about that graphic.

It's simple: CoolSceptic trying to set O.J. free again. He might succeed if he continues to get replied the usual style, so CoolSkeptic would probably be able to die filthy rich in spite of his client going impoverish and incarcerated for still being the way he was.

So I have a lot to say about that glove and those hands. Later, we will see if the trace of blood no jury could ignore needs to be shown to complete the task.

 

[lomiller]

Thank you for the clarification. Even in the example you gave however, the wild temperature fluctuation would remain within constraints, the negative feedback loop would just have wider amplitude. Or am I still missing something?

There are always constraints in physical systems. For example an unstable electric circuit will still be constrained by power supply driving that circuit. Venus, at some point, underwent a instable positive feedback loop of CO2 > warming > release CO2. Eventually the Carbon in the rocks of its crust were released into the atmosphere and the process stopped because the available carbon ran out.

In general negative feedback dampens the response to a stimulus while positive feedback amplifies the response to a stimulus. In the case of the earth’s climate we already know it response to very small signals that negative feedback would make even smaller. We require positive feedback to explain this.

While there is the possibility of a Venus style runaway positive feedback, this type of instability requires either forward gain or a large feedback factor, and neither of these seem to be in play on the earth. A billion years from now when the Sun is warmer and we are closer to that instability threshold then maybe...