Moderated Global Warming Discussion

[Trakar]

AFAIK this statement is incorrect that way. every doubling after a doubling will bring less additional warming.

and according to the IPCC the best estimate is 3°C for a doubling of CO2, but most estimates range from 2 - 4.5°C.

Speaking of multiple doublings can get confusing, as in: are we talking 250 + 250 + 250 ... or, are we talking 250 + 500 + 1000 ...

Typically, most climate studies are looking at doubling (trebling, etc.) of the pre-industrial concentration. I, personally, think that we need a longer-term yardstick like the average interglacial atmospheric CO2 concentration over the last million or so years. Getting a good (well supported) assessment of that is a pet project I've been working on for most of the last year. I'm making some progress, but initially, it seems that the interglacial average (at least for several interglacial periods) is somewhat less than our pre-industrial average, but I don't want to go too far down the path of analysing and discussing implications until I get further along in my project.

In general, you are correct that there should be diminishing returns for each doubling, but at the current pressure and concentration range, the variation is minor. It isn't until we get to much higher partial pressures that the drop off in successive doublings is dramatic.

As I was mentioning in earlier posts climate sensitivity is a peculiar problem as it is dependant upon an entire spectrum of system feedbacks (some of which may be unknown), some that operate on a near instantaneous time scale, some that operate over a period of years and decades, some that operate over a period of centuries and millenia. Many climate sensitivity studies only give heavy weighting to the known fast feedbacks that express themselves over time-frames of seconds to several decades, and largely ignore the slow feedback effects that operate on longer term periods of impact.

All this said, I believe the mean of most studies puts the fast feedback sensitivity (STP) at right around 3ºC with an MoE of +/- 1.5º which is in accord with the latest IPCC findings (range probably approximate for at least a few doublings - or halvings).

I can see that I have become too comfortable in my postings here, so I will return to the practice of qualifying these remarks as reflective of my readings, considerations and understandings, all of which are subject to alteration and refinement by presently unknown and future researches and evidences.

 

[Trakar]

...I will reply the rest of your post later.

If it is to be further personal attacks and rants that have nothing to do with climate science, spare the bandwidth, I am uninterested in such diatribes and strawman analogy argumentation.

 

[Trakar]

Before answering that, would you care to add first what do you think it would happen in case the GHG concentration remained constant in today's levels? That is a radically different scenario when compared with the one you quoted from me, the same different scenario you highlighted your own opinion (do I detect an induced inference there?)

I don't see any realistic manner that we could establish a constant level at today's pCO² concentration.

If we could wave a magic wand and stop all further anthropogenic emissions of CO2, it would not hold current levels at todays pCO² ratio. Surface temps would still continue to increase and natural sources would continue to emit additional CO2 until the climate systems fully equilibrate to the currently forced level. Full equilibration once forcing is removed is roughly estimated at thousands of years.

Without active removal of a lot of the CO2 we have already put into the environment, counting both fast and slow feedback systems, we are looking at thousands of years before our natural systems reach full equilibration and tens of thousands (or more) of years before natural processes bring our planet's climate back to levels that existed prior to our "contributions."

...or at the least, such is my understanding and considerations of the current researches and evidences of modern climate science.

 

[Kuko 4000]

About the rebound effect again, I found this:

http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:52011SC0277:EN:HTML:NOT

3.2.3. Other barriers

The rebound effect is another major challenge to energy savings. It implies that in spite of certain improvements of the efficiency of the individual products (e.g. appliances, cars and buildings), overall energy consumption linked to their use increases due to their increased volume, number or usage. This minimizes the savings from the efficiency improvements or in certain cases even leads to an absolute increase in energy consumption. For example, even though cars produced today are more efficient, the overall energy consumption of the car fleet grows because we use them more regularly and often buy bigger ones. The rebound effect is included in the assumptions of the various studies that make evaluation of the energy savings potentials and thus is not expected to hamper the possibilities for reaching the 20% energy savings target (see Box 1 for more details). The rebound effect is difficult to address it at EU level because it relates to increased living standards, freedom of choice and consumer behaviour.

The bolded part is indeed the thing that puzzles me. If a person saves a certain amount of money on heating per year, he might take an extra flight per year, etc. If you ctrl + f "rebound" you will find how they have taken the different aspects of the effect into account in their scenarios. I don't claim to understand half of it, but it seems to me like a very difficult and unpredictable variable to control.

 

[Kuko 4000]

...and the next link I clicked seems to show that it is indeed identified as a problem, among others, and that the EU is way behind on it's 20-20-20 plan when it comes to energy efficiency:

http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=SEC:2011:0280:FIN:EN:PDF

However, the EU is not on track to fully realize these cost-effective energy savings. The
PRIMES 2009 energy efficiency scenario shows a break in the trend towards ever increasing
energy demand but the reduction in consumption relative to previous projections will still be
only about 9% in 2020. Therefore, if the EU does not double its efforts on energy efficiency,
it will not reach its 20% target and will not realize all the associated benefits for the economy,
society and environment.


The causes of insufficient progress are market failures (such as insufficient price signals, split
incentives, asymmetric information, missing or incomplete markets and high initial costs) and
regulatory failures (such as lack of comprehensive policy frameworks, poor enforcement and
low level of ambition). The rebound effect is another challenge that, however, is difficult to
address at EU level as it relates to behaviour and the free choice of individuals.

It seems that EU is in good shape overall, in their 20-20-20 strategy though:

http://ec.europa.eu/clima/policies/package/faq_en.htm

The EU reduced GHG emissions from 7% below 1990 levels in 2005 to 10% below in 2008. This progress was due to increased climate policy action and high energy prices. Since 2008 the crisis has accelerated the reduction in emissions. In 2009, EU emissions were around 14% below 1990.

A certain rebound in emissions can be expected as the economy recovers but projections of future emissions show that with the measures already implemented today EU emissions would be at -14% compared to 1990 in 2020. The EU could even meet the 20% reduction target through domestic action alone, with additional policies to meet the 20% renewable energy target and limited additional regulatory and fiscal measures, and without recourse to international credits.

 

[macdoc]

Again "rebound" is not a climate science issue - it is appropriate to the GW Policy or the GW Solution thread as a known hindrance.

 

[Trakar]

Again "rebound" is not a climate science issue - it is appropriate to the GW Policy or the GW Solution thread as a known hindrance.

Or possibly deserving of its own thread in Social issues and current events; possibly combining the socio-psychological reactions and effects of climate change and humanity's attempts to deal-with/adjust-to this event.

 

[Trakar]

...What is our best estimate of climate sensitivity? I've heard that every doubling of the CO2 concentration in the atmosphere would mean an increase of 3 celsius in global average temp, I wonder what is the time scale of the temp rise relative to CO2 rise?

Any suggestions and ideas about communicating all this are very much appreciated, just writing about this here helps to get my thoughts together as well...

Remember that this isn't a discrete step process, the warming is happening as the concentration increases; it is the interplay of feedbacks which spreads the response out temporally. The near instaneous effects are primarily due to atmospheric radiative transfer factors whereby CO2 extends the mean free-path escape of longwave radiation (IR photons) from our atmosphere creating an temporal imbalance between the energy received from the Sun and the energy emitted from the Earth's environmental zone. CO2 slows the escape of the Sun's absorbed and re-emitted energies. The slower feedbacks result from how this distributes itself through out the atmosphere, oceans and surface of the planet and the impacts of this additional energy in our existant environmental systems.

...EDIT: And please let me know if I should move this discussion to a dedicated thread, I just think this could be helpful for some possible lurkers as well.

Here, or in its own thread makes little difference to the discussion, but it might make it easier for you to keep tabs on in its own thread, particularly when other subjects of interest in this general AGW thread become more active/distractive.

 

[spin0]

...and the next link I clicked seems to show that it is indeed identified as a problem, among others, and that the EU is way behind on it's 20-20-20 plan when it comes to energy efficiency:

Yes, keeping energy efficiency on track towards the 20% target has been problematic. Last year EU did introduce a new Directive on Energy Efficiency, and it's effectiveness remains to be seen.

It seems that EU is in good shape overall, in their 20-20-20 strategy though: http://ec.europa.eu/clima/policies/package/faq_en.htm

That item is a bit dated - last year it was reported that EU has done better than that by reaching 18% reduction of GHG's compared to 1990 levels: http://ec.europa.eu/clima/news/articles/news_2012102401_en.htm

The 2011 emissions are consistent with the decreasing trend observed since 2004. Despite a 48% GDP increase since 1990, greenhouse gas emissions in the EU-27 have decreased by 18%. The EU-15 and the 10 Member States that have individual commitments are on track to achieve their 2008-2012 emission reduction targets under the Kyoto Protocol.

Connie Hedegaard, European Commissioner for Climate Action, said: "The EU is delivering on its Kyoto commitment. While our economy grew 48 per cent since 1990, emissions are down 18%. These figures prove once again that emissions can be cut without sacrificing the economy. Now, it is important to keep the direction. Reaching the 20% target in 2020 does not come automatically. It calls for continued efforts. Furthermore, through new initiatives and legislation, like the Energy Efficiency Directive, the EU is on track to reduce more than the 20%."

That means EU is currently on track to overshoot the 20% reduction target, and it's quite possible to reach 25% (or maybe even that elusive 30%?).

BTW, I linked some very informative EU policy documents and roadmaps into this (lengthy) post: http://www.internationalskeptics.com/forums/showpost.php?p=8910198&postcount=7426

And you'll find more resources and information about progress of climate legislation in various countries here: http://www.internationalskeptics.com/forums/showpost.php?p=8937087&postcount=16

 

[aleCcowaN]

If it is to be further personal attacks and rants that have nothing to do with climate science, spare the bandwidth, I am uninterested in such diatribes and strawman analogy argumentation.

I don't see any realistic manner that we could establish a constant level at today's pCO² concentration.

If we could wave a magic wand and stop all further anthropogenic emissions of CO2, it would not hold current levels at todays pCO² ratio. Surface temps would still continue to increase and natural sources would continue to emit additional CO2 until the climate systems fully equilibrate to the currently forced level. Full equilibration once forcing is removed is roughly estimated at thousands of years.

Without active removal of a lot of the CO2 we have already put into the environment, counting both fast and slow feedback systems, we are looking at thousands of years before our natural systems reach full equilibration and tens of thousands (or more) of years before natural processes bring our planet's climate back to levels that existed prior to our "contributions."

...or at the least, such is my understanding and considerations of the current researches and evidences of modern climate science.

It doesn't look clear if it is indeed you who is 100% in the business of personal attacks and rants, but it is clear you don't read the messages of others and you're just flailing. Why? You're dancing rhetorically while you try to spiral off from the original few points, like you never addressing the fact your links in #7524 (the post starting this) didn't back your assertions in there. Your reaction to that was a smoke screen and a change of subject by a personal attack conducted by faking .

Let's remember what you wrote in #7533: "My comments were addendums intended only to offer understandings and current information that is not in accord with the apparent assertion that humanity could drop our CO2 emissions to half their current annual level" and the random links were sort of "general knowledge: annotated links by Trakar" and addressed to a jerkish character that is making dumb assertions. But actually it can be translated into "oops, I only scanned 'them links'; let's try to cast attention elsewhere".

You then went on with your careful construction of misrepresenting what I had said and "answered" those misrepresentations with the subject you wanted to speak about. The cuckoo brood parasitism, the same one that characterizes diehard denialists and it's quite evident now you share a background with them.

The hard fact is that in #7543 you are replying to a question asked to macdoc, a question asked in order to fully reply his previous question, but mostly asked for him -and you- to realize that both had make the mistake of mixing up constant GHG levels, stop emitting and what is implied by "warming still in the pipe" when figures are to be given; a mistake fostered by an attitude of quickly translating every consideration into the worst possible scenario by pairing the worst word chain ("stop dead all emissions") with the worst figure ("0.8°C still on the pipe"), dressing that custom salad with spicy hidden threats like methane-bombs, the rebellion of the carbon sinks -which will raise and vomit all the carbon they were forced to swallow- and the final exhalation -full of carbon dioxide- of Gea. Instead, you chose to begin with a lame remark on the impracticality of keeping constant GHG levels to follow it by wasting your breath in generalities, repeating a lot of what I've already said. It was just a smoke screen: you were both mistaken with your values in the first time.

I repeat what I said in #7516 and #7523: +1 to 1.2°C in 250 years with constant levels, a peak of +0.2°C about 30 years before stop 'cold turkey' every GHG emissions. This never contained "policies" nor "likelihood" as it was part of an explanation about the meaning of the elastic "there's warming still in the pipe". Your abusive speculations and wild disgressions were just a smoke screen to hide that you and macdoc didn't understand what I said in the first place. And no ESL was the cause of it.

 

[bobwtfomg]

If we could wave a magic wand and stop all further anthropogenic emissions of CO2, it would not hold current levels at todays pCO² ratio. Surface temps would still continue to increase and natural sources would continue to emit additional CO2 until the climate systems fully equilibrate to the currently forced level. Full equilibration once forcing is removed is roughly estimated at thousands of years.

.

It is my, admittedly limited, understanding of the science that almost half of current anthropogenic CO2 emissions are being absorbed by the oceans/biosphere, whilst I've read that there are concerns that these carbon sinks are becoming less effective as temp and ocean CO2 concentration continue to rise, I've not come across the idea that they might suddenly turn into emitters of CO2.
Is this backed by any science? Got a link?

If it is to be further personal attacks and rants that have nothing to do with climate science, spare the bandwidth, I am uninterested in such diatribes and strawman analogy argumentation.

Your abusive speculations and wild disgressions were just a smoke screen to hide that you and macdoc didn't understand what I said in the first place. And no ESL was the cause of it.

Can you guys please stop the bitch slapping flame war it's a bit of a thread derailer

Oh and Alec, no offence meant, but your English, though very good, isn't as perfect as you may think it is. Sometimes your sentence constuction leaves your meaning somewhat ambiguous. For example "And no ESL was the cause of it" as it stands is meaningless. On it's own I would interpret it as "And no, ESL was the cause of it" where you're saying "ESL was the cause" and prefixing this with "And no" to contradict a previous statement and add emphasis. From context though I'm guessing you meant "And ESL wasn't the cause of it" or possibly "And no, ESL wasn't the cause of it"

 

[Pixel42]

It is my, admittedly limited, understanding of the science that almost half of current anthropogenic CO2 emissions are being absorbed by the oceans/biosphere, whilst I've read that there are concerns that these carbon sinks are becoming less effective as temp and ocean CO2 concentration continue to rise, I've not come across the idea that they might suddenly turn into emitters of CO2.
Is this backed by any science? Got a link?

Cold water can hold more CO2 than warm water. Once the temperature has risen to the point that the oceans are saturated with CO2 they cease to absorb it, and if temperature continues to rise they start to release it. This is why the amount of CO2 in the atmosphere varies between about 200ppm during a glacial period and about 300ppm during an inter-glacial - CO2 is absorbed when the temperature falls and released when the temperature rises. This is one of the positive feedbacks that explains why global temperatures vary so greatly as a result of the relatively small forcing of the Milankovich cycles.

Here's an article from skeptical science on this:

http://www.skepticalscience.com/skakun-co2-temp-lag.html

 

[bobwtfomg]

Thanks for the link, interesting article but it didn't directly address the question I asked trakar.

I get it that when there was 200ppm CO2, an orbital forcing began and warmed the southern oceans, after a few hundred years CO2 levels in the atmosphere begin to rise, which it's assumed came from the ocean, this acts as a feedback multiplying the orbital forcing, global temperatures and CO2 levels continue to rise slowly for about 8000 years before roughly leveling out.

But it seems to me that whether the oceans absorb or emit CO2 must depend on not only the ocean's temperature, but also on the levels of atmospheric CO2 (and probably many other factors as well) which are now about 50% higher than at the start of the holocene . If there's been any recent reseach that suggests the ocean is close to stopping being a carbon sink, I'm afraid I missed it.

 

[CapelDodger]

Can you guys please stop the bitch slapping flame war it's a bit of a thread derailer

I second that. We may not get deniers here anymore, apart from Haig's cyclical drive-bys, but that's no reason for turning on each other. We have differences, naturally, in both style and focus, but not about the basics.

Regarding oceanic CO₂ sinks, I haven't saved links but I have read credible arguments that they may well be weakening, based purely on physics and the fact that atmospheric CO₂ does rise as a response to Milankovich warming and that seems unlikely to be due primarily to the poleward retreat of the permafrost belt. Given that the current rate of accumulation is already a problem, and depends essentially on economics and industrial development in the BRIC nations, it strikes me as a minor point. Time will provide more data to resolve the issue, and lets face it, our current understanding of climate will be regarded as pretty primitive in a few generations. We still largely depend on ice-age proxies, not the grand experiment which is in progress.

 

[macdoc]

Alec

I repeat what I said in #7516 and #7523: +1 to 1.2°C in 250 years with constant levels, a peak of +0.2°C about 30 years before stop 'cold turkey' every GHG emissions. This never contained "policies" nor "likelihood" as it was part of an explanation about the meaning of the elastic "there's warming still in the pipe". Your abusive speculations and wild disgressions were just a smoke screen to hide that you and macdoc didn't understand what I said in the first place. And no ESL was the cause of it.

Stop including me in your diatribes. I asked Trakar a question not you. Where did he get 0.2 degree to equilibrium on a stopping cold scenario.?

I repeat what I said in #7516 and #7523: +1 to 1.2°C in 250 years with constant levels, a peak of +0.2°C about 30 years before stop 'cold turkey' every GHG emissions.

+1 to 1.2 ...from where Alec -??? you think you are being clear - you are not.
With no baseline it's meaningless....is this base period: 1951-1980? That's what NASA uses and we are .76C over so above that at 396 ppm.

How do you square your +1 to 1.2C in 250 years with this from Real Climate

So given that we will exceed 400 ppm CO2 in the near future, is a target of 2°C feasible? To make a long story short: the answer is yes.

The following paragraphs attempt to shed a little light on the background on why 2°C and 400 ppm are mentioned together. First of all, ‘CO2-equivalent concentration’ expresses the radiative forcing effect of all human-induced greenhouse gases and aerosols as if we only changed CO2 concentrations. We use that as shorthand for the net human perturbation – it’s not the same as real CO2 being at 400 ppm because of the substantial cooling effect from aerosols. However, the other greenhouse gases such as methane and N2O increase the forcing and compensate somewhat for the aerosol effects. Thus the CO2-equivalent concentration is roughly equal to current levels of real CO2.

The ecosystems on our planet are a little like a cat in an oven. We control the heating (greenhouse gas concentrations) and the cat responds to that temperature.

So far, we have turned the controls to a medium level, and the oven is still warming-up. If we keep the oven control at today’s medium level, the cat will warm beyond today’s slight fever of 0.8°C.

And if we crank the control up a bit further over the next ten years and leave it there, the fever is going to get a little worse – and there is even a 4 in 1 chance that it could exceed 2°C.

http://www.realclimate.org/index.php/archives/2006/01/can-2c-warming-be-avoided/

and

this from another realclimate article on a stop cold scenario - here is the graph

The upper line is often what is referred to as the ‘climate change commitment’ (for instance Wigley, 2005). This is the warming you get if we keep CO2 (and other GHG and pollutant levels) constant at today’s values. (Technically, the figure shows the case staying at year 2000 values). In such a scenario, the planet still has a radiative imbalance, and the warming will continue until the oceans have warmed sufficiently to equalise the situation – giving an additional 0.3 to 0.8ºC warming over the 21st Century. Thus the conclusion has been that because of climate inertia, further warming is inevitable.

http://www.realclimate.org/index.php/archives/2010/03/climate-change-commitments/

unless you were implying a drop from 2.0 degrees over base period anticipated in the 400 ppm article above, to 1.0 to 1.2C over that same baseline 250 years out.

In other words the global temperature declines with no additional anthro C02.??

At all times under all scenarios with anthro C02, due to the lag, there will be a certain amount of warming to come until equilibrium is reached....when is that point?
From the graph above it's not hitting equlibrium even 300 years out.

••••
Alec wrote

And yes, the up to 1°C in +150 years is above the present conditions and not those of 1880.

So you are not using the NASA baseline at all but one that already includes the .76 observed to date above their baseline. !!!!!
C'mon Alec that's awfully confusing.

 

[Doctor Plop]

Oh look.
Trying to give life meaning by clinging to political ideology in all its forms failed and killed millions, so the new materialist religion has had to move away from human beings and their interactions.

Now it's the *********** weather.

Get a grip.

 

[BenBurch]

Trouble with scenarios like that, MacDoc, is that they assume that we will not have any amplifications we trigger as the heat rises.

I think we may have one or two of those in store even if we decide to live like the Amish.

 

[DC]

Oh look.
Trying to give life meaning by clinging to political ideology in all its forms failed and killed millions, so the new materialist religion has had to move away from human beings and their interactions.

Now it's the *********** weather.

Get a grip.

climate, not weather.

 

[Kuko 4000]

I realize that Bill McKibben is pretty much in the camp extreme, but this quote was the source for my question:

http://www.rollingstone.com/politics/news/global-warmings-terrifying-new-math-20120719?page=2

But, in fact, computer models calculate that even if we stopped increasing CO2 now, the temperature would likely still rise another 0.8 degrees, as previously released carbon continues to overheat the atmosphere. That means we're already three-quarters of the way to the two-degree target.

 

[macdoc]

Ben

Trouble with scenarios like that, MacDoc, is that they assume that we will not have any amplifications we trigger as the heat rises.

Working generally with what we know -kept under 2 degrees rise from NASA baseline ( unlikely as it is at this point )which was the premise of the articles quote - then that keeps the risk of a tipping point quite low.
Of course there are unknown elements of risk to encounter but those could be negative forcing as well.....the number of shiny cell phones in use has reflected enough solar to .......