Moderated Global Warming Discussion

[BenBurch]

Speaking of coal and carbon black....



http://www.bbc.co.uk/news/science-environment-21033078

You might recall where I predicted this about 2007-ish...

 

[Kuko 4000]

Fact check #1

Hmm, have I got the logic right...?

To stop emitting CO2 and CFC -let's leave aside other GHG- implies atmospheric CO2 dropping some 1 ppmv per year, so the planet would be likely warming a bit more and then stay there -or viceversa- for, let's say, 30 years, to then start a slightly cooling trend.

Is this because after 30 years the concentration would be at 350 ppm, and this is considered to be the maximum concentration which keeps the global warming in check, at least when it comes to human influences?

To keep the actual level of CO2 -396 ppmv probable 2013 average- implies no stopping with our emissions but curbing them about 50% and staying there. In that case, complex models that involve an adequate representation of the ocean system would probably give some raise of 1 to 1.2°C in 250 years with most of it in the next 60 or 70.

So to stay at our current CO2 levels (396 ppm) we would need to cut down our current emissions about 50% and stay there? Could you open this a little bit more, but as simply as possible, my non-mathematically trained brain is probably on a wrong track even before I start thinking about the reasons. That raise of about 1c is, I suppose, on top the 0.8c that has already happened since 1900*? This would keep us in the 2c warming scenario.

* Btw. what is the year that IPCC uses as a base year when they talk about increases in temperature? Pre-industrial (however you define it), 1750, 1850, 1900, 1970, I've heard many different versions of this...and I'd like to make it clear for lay people like me in my project.

 

[aleCcowaN]

Is this because after 30 years the concentration would be at 350 ppm, and this is considered to be the maximum concentration which keeps the global warming in check, at least when it comes to human influences?

The reason is the climate depending on the oceans temperature in the long run. Since the beginning of the industrial revolution oceans have warmed about 0.2°C. The 30-year delay -a period proposed for the sake of analysis- is the macro version of the delay that causes that on June 21th your location gets the most energy from the Sun but the warmest day of the year -as an average- is between July 12 and August 20 -depending on what non-tropical location of the Northern Hemisphere you are. The key concept is thermal inertia and the oceans are the behemoth in this area: suppose you trapped all the energy that the planet gets from the Sun and it doesn't reflect via albedo; the ocean temperature would raise just about 1°C per year.

So to stay at our current CO2 levels (396 ppm) we would need to cut down our current emissions about 50% and stay there? Could you open this a little bit more, but as simply as possible, my non-mathematically trained brain is probably on a wrong track even before I start thinking about the reasons. That raise of about 1c is, I suppose, on top the 0.8c that has already happened since 1900*? This would keep us in the 2c warming scenario.

We simply can emit as much as the planet can absorb: as the atmosphere has a CO2 concentration of 396 ppmv but the oceans as an average are reflecting an old planet with some, let's say the atmospheric equivalent to 300 or 310 ppmv -not in the surface which is becoming increasingly less alkaline- what is another transient effect owing to inertia, it happens that the ocean is taking some 9 to 12 GT of CO2 each year. Throw 2 or 3 GT for other sinks an you get how much we can emit without making things worse in the radiation forcing angle.

You have to deal with all this like you were saying "the cigarette of today causes the emphysema of tomorrow" to people that say "I'm feeling good, besides the doctor said I have no sign of emphysema now" while denialists are saying "my grandpa smoke all his life a he died 95 when a tramway drove over him".

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

* Btw. what is the year that IPCC uses as a base year when they talk about increases in temperature? Pre-industrial (however you define it), 1750, 1850, 1900, 1970, I've heard many different versions of this...and I'd like to make it clear for lay people like me in my project.

A practical approach is 1850 to 1880

 

[Trakar]

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

A practical approach is 1850 to 1880

It is good to remember that even short-term equilibration at zero additional emissions is about 30 years (so we wouldn't stop increasing temps and impacts for a generation and a half) and long-term (slow) equilibration will take centuries. Additionally, all of this assumes that we have not already triggered the process of natural surface sinks turning into carbon sources that take up the slack of diminished/eliminated human emission sources.

"Permafrost carbon-climate feedbacks accelerate global warming" - http://www.pnas.org/content/early/2011/08/17/1103910108.full.pdf+html

LIkewise, within a very short period the ocean saturation levels could easily shift those massive reservoirs from being a net C sink into being a net C emission source.

http://www.climate.org/topics/climate-change/ocean-uptake-climate-change.html

 

[aleCcowaN]

It is good to remember that even short-term equilibration at zero additional emissions is about 30 years (so we wouldn't stop increasing temps and impacts for a generation and a half) and long-term (slow) equilibration will take centuries.

Yes, a global raise of some 0.2°C is still to be expected in the case we stopped our emissions "cold turkey". But "equilibration" is to be reached in some 150 or 200 years. What can take centuries to finally set is all the climate configurations that our descendants would experience, like little ice ages and warm periods like the historical local ones.

Additionally, all of this assumes that we have not already triggered the process of natural surface sinks turning into carbon sources that take up the slack of diminished/eliminated human emission sources.

"Permafrost carbon-climate feedbacks accelerate global warming" - http://www.pnas.org/content/early/2011/08/17/1103910108.full.pdf+html

LIkewise, within a very short period the ocean saturation levels could easily shift those massive reservoirs from being a net C sink into being a net C emission source.

http://www.climate.org/topics/climate-change/ocean-uptake-climate-change.html

These ones have been overly exaggerated. One comes from the role of the upwelling zones as a normal carbon source and proposes an exacerbation of it with complete neglection of the exacerbation of the compensatory processes -like water going up but not coming down-. The other one even exploits the Arctic born methane that is biologically created every warm season, when in fact methane deposits in the first 300 metres are not so abundant as those bombs exploded in other warm periods during the past few million years. Not minor threats, certainly, but exaggerated anyway, especially in a context of a few tenths more like we're analysing now here.

I completely disagree and resent both the approach of the denialists, who manipulate by using induced inferences -nothing to do with inductive inferences- to manage the people or simply lie brazenly, specially those who love to be managed or to be lied, and the approach or the warmers who desperate on the success of their rivals and the general inaction decide to compile lists of impending dooms in order to be heard.

 

[Trakar]

Yes, a global raise of some 0.2°C is still to be expected in the case we stopped our emissions "cold turkey". But "equilibration" is to be reached in some 150 or 200 years. What can take centuries to finally set is all the climate configurations that our descendants would experience, like little ice ages and warm periods like the historical local ones.



These ones have been overly exaggerated. One comes from the role of the upwelling zones as a normal carbon source and proposes an exacerbation of it with complete neglection of the exacerbation of the compensatory processes -like water going up but not coming down-. The other one even exploits the Arctic born methane that is biologically created every warm season, when in fact methane deposits in the first 300 metres are not so abundant as those bombs exploded in other warm periods during the past few million years. Not minor threats, certainly, but exaggerated anyway, especially in a context of a few tenths more like we're analysing now here.

I completely disagree and resent both the approach of the denialists, who manipulate by using induced inferences -nothing to do with inductive inferences- to manage the people or simply lie brazenly, specially those who love to be managed or to be lied, and the approach or the warmers who desperate on the success of their rivals and the general inaction decide to compile lists of impending dooms in order to be heard.

I find your considerations of these issues to be overly conservative and out of touch with current publication and finding. Not that everyone will ever be of one mind, but rhetorical dismissal does not make for a scientifically compelling argument.

 

[aleCcowaN]

I find your considerations of these issues to be overly conservative and out of touch with current publication and finding. Not that everyone will ever be of one mind, but rhetorical dismissal does not make for a scientifically compelling argument.

I'm not going to repeat what I've already said on the subject every time this appears. If you chose to ignore what the thousand previous posts contain and call it rhetorical dismissal is just your choice of words. I'm not explaining Haig why global warming is happening either because there are +20,000 posts doing that here.

I'd hate that Kuko's video contained even the slightest alarming bit of those that only are sustained by a selection of sources where the selecting factor is conformation to one's own visions, being the "what if" factor the most probable in action.

 

[DC]

I'm not going to repeat what I've already said on the subject every time this appears. If you chose to ignore what the thousand previous posts contain and call it rhetorical dismissal is just your choice of words. I'm not explaining Haig why global warming is happening either because there are +20,000 posts doing that here.

I'd hate that Kuko's video contained even the slightest alarming bit of those that only are sustained by a selection of sources where the selecting factor is conformation to one's own visions, being the "what if" factor the most probable in action.

you expect others to go true this monster of a topic to find your reasoning for dismissing the scientific findings?

 

[Trakar]

I'm not going to repeat what I've already said on the subject every time this appears. If you chose to ignore what the thousand previous posts contain and call it rhetorical dismissal is just your choice of words. I'm not explaining Haig why global warming is happening either because there are +20,000 posts doing that here.

I'd hate that Kuko's video contained even the slightest alarming bit of those that only are sustained by a selection of sources where the selecting factor is conformation to one's own visions, being the "what if" factor the most probable in action.

I have been a participant in this thread for most all of its existence, and a contributor of a significant fraction of those posts, no offense was intended in my statements, but nothing you have offered here refutes my statements or compellingly supports your assertions. I can accept your perspective and considerations for what they are, your subjective opinion of the issue, but I do not agree with the particulars of that opinion as you have laid them out, nor have I seen a wealth of modern/recent published references and evidences that compellingly support that perspective. If you would like to offer such support I would be more than willing to read it, consider it, and if necessary re-evaluate my current understandings.

 

[aleCcowaN]

you expect others to go true this monster of a topic to find your reasoning for dismissing the scientific findings?

What problem do you have doing that? I do it myself all the time with everybody's opinion. That's why we have brains and Internet and the fora themselves have search engines.

Otherwise you don't understand what rhetorical dismissal means. Everyone is bound to be diligent firstly before using such assertions.

From your words I understand you read here just what caught your interest and you have a bad memory.

 

[aleCcowaN]

I have been a participant in this thread for most all of its existence, and a contributor of a significant fraction of those posts, no offense was intended in my statements, but nothing you have offered here refutes my statements or compellingly supports your assertions. I can accept your perspective and considerations for what they are, your subjective opinion of the issue, but I do not agree with the particulars of that opinion as you have laid them out, nor have I seen a wealth of modern/recent published references and evidences that compellingly support that perspective. If you would like to offer such support I would be more than willing to read it, consider it, and if necessary re-evaluate my current understandings.

Sorry, but your statements don't state a iota or state the wrong thing. You jumped into a conversation dealing with a range between keeping the actual CO2 level and letting it drop slowly by stopping all emissions -its likelihood is not on debate because the person asking that was just trying to understand how that worked and not other possibilities-.

To my reply to that, you replied by saying "all of this assumes that we have not already triggered the process of natural surface sinks turning into carbon sources that take up the slack of diminished/eliminated human emission sources" to link a paper which discusses that way out of the range we were talking: The paper says, among many things, that by 2100 the permafrost would become a source instead of being a sink when using an (SRES) A2 climate change scenario with a CO2 level circa 1000 ppm and a likely temperature raise of +3°C. So your paper confirms "we haven't triggered..." so there's nothing to assume as you thought "all of this" assumed.

But it could be an isolated misunderstanding. Let's check the following paragraph of yours: "LIkewise, within a very short period the ocean saturation levels could easily shift those massive reservoirs from being a net C sink into being a net C emission source", a bold assertion. Let's look at your link: "Climate Institute" , an article by Magali Devic whose area seem to be business judging by her Global MBA. But this article doesn't say what you told it said. There's nothing there even remotely close to within a very short period ... the ocean saturation levels ... could easily shift (you were specially shameless using this bit) ... those massive reservoirs ... from being a sink into being a net source. This is a fake story that is just in your mind. The only remotely close to that sudden change of ocean "behaviour" is the bit referring to Schuster and Watson's paper for the North Atlantic, what is not a rule, as the local intake of CO2 in recent times have been there much greater that other ocean areas, as its abrupt acidification shows. That is complemented by simple logical reasoning when you see the temperature profile of the ocean in different depths (browse my image albums).

So, what you said was totally out of the scope of what we were speaking and it's just an exaggeration that your own links can't sustain. I insist what you did was just "what-if-ism" and plain alarmism the kind of "beware, it may happen!".

There never was there nothing serious that requires for me to pile up here papers and reasoning to try to convince you. There were no reasoning at all, just the feel of speaking and playing with possible dooms, which is a vice increasingly common in these logic-forgotten fora.

 

[macdoc]

Trakar

Yes, a global raise of some 0.2°C is still to be expected in the case we stopped our emissions "cold turkey". But "equilibration" is to be reached in some 150 or 200 years. What can take centuries to finally set is all the climate configurations that our descendants would experience, like little ice ages and warm periods like the historical local ones.

That is not my understanding at all if we stopped cold which we will no.
0.6 in the pipeline and barring any significant feedbacks being triggered ....about 30-60 years to reach equilibrium.
I'd be happy to see reliable source where you got other figures.

The natural drift down due to the orbital positioning would re-assert at some point after that.

 

[Trakar]

As you seem invested in interpretting my words according to some strange standard that is not in accord with the manner in which they were offered, I will overlook the apparent personal insults and attacks and try to address only the peculiarly requested clarifications.

Sorry, but your statements don't state a iota or state the wrong thing. You jumped into a conversation dealing with a range between keeping the actual CO2 level and letting it drop slowly by stopping all emissions -its likelihood is not on debate because the person asking that was just trying to understand how that worked and not other possibilities-.

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 (essentially mid to late '70s emission levels) and it would stabilize our atmospheric concentration of CO2 at current levels. This is not at all accurate to my understanding of current rates of increase, the length of time it will practically take us to "put on the brakes" and slow to a zero increase rate, yet alone drop emissions to mid 1970s levels (which btw was out of balance back when we were emitting at those levels in the mid-1970s). While this may, eventually, slow the rate of temperature and atmospheric CO2 concentration increases, it would not stop them. Additionally, during the several decades that we are dropping our emission rate of increase to zero and then the additional decades it would take to pull the level of emissions back to seventies levels we would far surpass the first doubling and be quickly approaching a trebling of pre-industrial atmospheric CO2 concentration levels, with surface temperature estimates estimated at ~4-6 degrees C increase over current global averages.

To my reply to that, you replied by saying "all of this assumes that we have not already triggered the process of natural surface sinks turning into carbon sources that take up the slack of diminished/eliminated human emission sources"

In context, that statement is referring to a future time when we have managed to drop our rates of increase to zero, and actually reduced our average global emission levels to that of the mid 1970s. I would be quite surprised if the oceans and soils of this planet have not become net emitters of stored CO2 over the next 5-6 decades, but it would not surprise me much if this transition occurs within the next 2-3 decades at our current rates of increasing CO2 emission (BTW 5-6 decades is extremely rapid for the issues I am talking about, heck, 3-4 centuries is almost "instantaneous" for usual considerations of such geologic events). There are already signs that areas of the ocean and soils are demonstrating reduced uptake and saturation of atmospheric CO2. There are already substantive increases of CO2 and Methane emissions from large segments of northern permafrost.

...to link a paper which discusses that way out of the range we were talking: The paper says, among many things, that by 2100 the permafrost would become a source instead of being a sink when using an (SRES) A2 climate change scenario with a CO2 level circa 1000 ppm and a likely temperature raise of +3°C. So your paper confirms "we haven't triggered..." so there's nothing to assume as you thought "all of this" assumed.

This is affirming much of what I have been saying, which is why I used it as a reference example of current mainstream consideration of the issue by one of the pre-eminent researchers in modern climatology.

But it could be an isolated misunderstanding. Let's check the following paragraph of yours: "LIkewise, within a very short period the ocean saturation levels could easily shift those massive reservoirs from being a net C sink into being a net C emission source", a bold assertion. Let's look at your link: "Climate Institute" , an article by Magali Devic whose area seem to be business judging by her Global MBA. But this article doesn't say what you told it said. There's nothing there even remotely close to within a very short period ... the ocean saturation levels ... could easily shift (you were specially shameless using this bit) ... those massive reservoirs ... from being a sink into being a net source. This is a fake story that is just in your mind. The only remotely close to that sudden change of ocean "behaviour" is the bit referring to Schuster and Watson's paper for the North Atlantic, what is not a rule, as the local intake of CO2 in recent times have been there much greater that other ocean areas, as its abrupt acidification shows. That is complemented by simple logical reasoning when you see the temperature profile of the ocean in different depths (browse my image albums).

Perhaps our disagreements are more strongly language related than understanding related. Or for some reason you simply did not like or appreciate the reference example I provided. It was only offered as an example to demonstrate that my considerations and understandings of these issues were not some independant outlier, but rather a completely mainstream modern climate science consideration.

Additional references if they will help clarify and enhance understandings here:

"Trends and regional distributions of land and ocean carbon sinks"
http://biogeosciences.net/7/2351/2010/bg-7-2351-2010.pdf

"Significant contribution to climate warming from the permafrost carbon feedback
http://www.nature.com/ngeo/journal/v5/n10/full/ngeo1573.html

"Amount and timing of permafrost carbon release in response to climate warming"
http://www.tellusb.net/coaction/index.php/tellusb/article/download/16197/18105

"Atlantic Ocean CO2 uptake reduced by weakening of the meridional overturning circulation"
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1680.html

Again, these are not intended as iconic proofs of concept, rather they are merely intended as examples of the types of concerns I mention and to illustrate that the issues I mention are legitimate, mainstream climate science considerations and concerns.

So, what you said was totally out of the scope of what we were speaking and it's just an exaggeration that your own links can't sustain. I insist what you did was just "what-if-ism" and plain alarmism the kind of "beware, it may happen!".

There never was there nothing serious that requires for me to pile up here papers and reasoning to try to convince you. There were no reasoning at all, just the feel of speaking and playing with possible dooms, which is a vice increasingly common in these logic-forgotten fora.

Perhaps it is the language problems which make these types of statements seem to me as though they were unsubstantiated polemic rhetoric, but I really don't know how else to interpret the arguments being made.

 

[macdoc]

Trakar - hint ESL. - look at Alec' sig.

Now where did you get 0.2 in the pipeline?

 

[Trakar]

Trakar


That is not my understanding at all if we stopped cold which we will no.
0.6 in the pipeline and barring any significant feedbacks being triggered ....about 30-60 years to reach equilibrium.
I'd be happy to see reliable source where you got other figures.

The natural drift down due to the orbital positioning would re-assert at some point after that.

Your quoted material is from aleCcowaN's post - http://www.internationalskeptics.com/forums/showpost.php?p=8937529&postcount=7525

I can give you the ratios from Hansen and Archer (or the other sources I tend to use) for fast and slow feedback equilibrations, but they are different from his post's figures.

 

[Trakar]

Trakar - hint ESL. - look at Alec' sig.

Now where did you get 0.2 in the pipeline?

I well understand his language issue which is why I mentioned it.

the 0.2 is His statement, not mine.

 

[aleCcowaN]

Trakar


That is not my understanding at all if we stopped cold which we will no.
0.6 in the pipeline and barring any significant feedbacks being triggered ....about 30-60 years to reach equilibrium.
I'd be happy to see reliable source where you got other figures.

The natural drift down due to the orbital positioning would re-assert at some point after that.

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?)

 

[aleCcowaN]

As you seem invested in interpretting my words according to some strange standard that is not in accord with the manner in which they were offered, I will overlook the apparent personal insults and attacks and try to address only the peculiarly requested clarifications.



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 (essentially mid to late '70s emission levels) and it would stabilize our atmospheric concentration of CO2 at current levels. This is not at all accurate to my understanding of current rates of increase, the length of time it will practically take us to "put on the brakes" and slow to a zero increase rate, yet alone drop emissions to mid 1970s levels (which btw was out of balance back when we were emitting at those levels in the mid-1970s). While this may, eventually, slow the rate of temperature and atmospheric CO2 concentration increases, it would not stop them. Additionally, during the several decades that we are dropping our emission rate of increase to zero and then the additional decades it would take to pull the level of emissions back to seventies levels we would far surpass the first doubling and be quickly approaching a trebling of pre-industrial atmospheric CO2 concentration levels, with surface temperature estimates estimated at ~4-6 degrees C increase over current global averages.

<snip snip snip>

What you have done is basically this: I say "if I dropped a hammer from the tenth floor it would kill a person standing in the street" and you reply with a string of unrelated topics like "why are you dropping hammers?", "what if the hammer drops on the person's shoulder?, "do you hold any grudge against that person?", "are you sure the building has a place from which you may drop a hammer into the street?".

You only intervened in my answer to Kuko 4000 who only tried to understand what's behind the notion of GW still on in spite of mankind stop polluting. My answer mainly aimed to avoid the vulgar confusion between constant levels of GHG and stop emitting GHG. You made it first into a parade of explosive positive feedbacks that lie rampant like the lion. Now you are criticizing if that is a reasonable scenario. You were off that topic, you still are off that topic, and I suspect you'll remain off that topic no matter what I say.

I suppose that will teach Kuko to look elsewhere for help in understanding the topic without being sold other things in the process.

I will reply the rest of your post later.

 

[Kuko 4000]

Communication #1

Communication tips #1 + more fact checking

I'm struggling a bit on how to communicate the urgency of the matter, I'd like to keep everything as simple as possible so that everyone can understand it, but I'd also like to give some reliable and possibly new details at the same time for people who are at least superficially interested in the subject, I can easily add simple graphs and numbers to the video. I want to make my own graphs, because I think the official ones are too distracting for the lay audience.

For example, what happens and at what time scales if we continue "business as usual" until 2050, etc.

This is a good starting point:

http://phys.org/news/2012-07-china-co2-person-europe.html

China's carbon dioxide (CO2) levels soared in 2011, putting its per capita emissions on a par for the first time with those of Europe, while global levels of the greenhouse gas hit another all-time high, a report released Wednesday said

The United Nations has adopted a target of limiting global warming to 2.0 degrees Celsius (3.6 Fahrenheit) by 2050.

Scientists think this is feasible as long as cumulative CO2 emissions between 2000 and 2050 do not exceed 1,000 to 1,500 billion tonnes.

Since 2000, human activities have led to about 420 billion tonnes of CO2 being sent into the atmosphere, and on current trends the ceiling will be breached "within the next two decades," the report warned.

+ The IPCC scenarios.

+ How are the current strategies actually working, and what are they?

+ 20-20-20 in EU, AFAIK, is going along nicely, but what about elsewhere? And is this enough to limit the warming to 2 celsius if everyone would do it?

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

These targets, known as the "20-20-20" targets, set three key objectives for 2020:

A 20% reduction in EU greenhouse gas emissions from 1990 levels;

Raising the share of EU energy consumption produced from renewable resources to 20%;

A 20% improvement in the EU's energy efficiency.

Also, I need more catchy (but correct) examples like:

The best estimates agree that the amoung of energy we use as a humanity doubles by the year xxxx and the problem is that currently over 80% of all the energy is produced by burning coal, oil and natural gases, and this trend has not slowed down in the last xxx years.

"xxx years ago there was xxx metres of ice on top of New York, and the average global temperature was x celsius colder than now."

"xxx years ago New York would have been under xxx metres of water while the average global temp was x celsius warmer than now."

"Since 1900 the earth has warmed on average 0.8 celsius, but for example, Antarctica has warmed x.x celsius in the same time period."

Can anyone fill in the XXX:s? I remember hearing something like this once, and wanted to add them to my vocabulary, but...clearly it didn't happen. And I can't seem to find them with my Google-fu. Something similar would be great.


http://www.slate.com/blogs/bad_astr...why_don_t_they_publish_scientific_papers.html

13,950 peer-reviewed climate articles between 1991 - 2012, only 24 reject global warming.

Nine of the ten hottest years on record (records go back 130 years?) have been since 2000.

"Without the greenhouse effect, our Earth would have and average temperature of -19 celsius."

"The earth's athmosphere is about as thin as the skin of an apple, relative."

"PPM numbers are higher now than at any time in the, at least, previous 800 000 years."

"The rate of glacier melt is accelerating, in southern Greenland, the amount of ice flowing into sea has doubled in the last 10 years due to AGW."

Is this accurate? And what is the current estimation of the conditions required for the unreversable tipping point of Greenland melting?

EDIT: Related: http://www.slate.com/blogs/bad_astr...nd_and_antarctic_ice_and_contributing_to.html

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...


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.

 

[DC]

Communication tips #1 + more fact checking

...
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?

....

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.