2010-08-23 22:32:43Basic rebuttal 101: "CO2 is not the only driver of climate" - REVISION 4
Michael Searcy

scentofpine@yahoo...
72.91.223.97

Industrial CO2: Relentless warming taskmaster

SEE REVISION 4, DOWN THE PAGE

At any given time, the Earth’s climate is subjected to a myriad of natural influences.  These influences range from changes in the planet’s orbit around the Sun and shifts in continental tectonic plates to volcanic eruptions, variations in solar activity, and changes in wind and ocean patterns.  These influences vary based on the magnitude of the natural change, the duration over which the change occurs, and whether or not that change is part of an overall repeated cycle.  This combination of magnitude, duration, and cyclicity determines the impact of the influence on the climate system.

Continual shifts in tectonic plates and cyclical changes in Earth’s orbit around the Sun can completely alter the face of the planet.  However, these changes occur over the course of thousands of years.

Volcanic eruptions and impacts from celestial bodies, like asteroids, have an immediate and one-time influence.  However, very few incidents of these events are of sufficient size to impact the global climate.

Variations in solar activity and wind and ocean patterns can have an impact over the course of months to decades, but each of these influences has a correspondingly short cycle, alternating between promoting warming and cooling conditions.
 
What differentiates the human industrial contribution of carbon dioxide (CO2) to the atmosphere is that it is happening very rapidly, is not cyclical, and drives up the atmospheric concentration of the primary long-lived greenhouse gas, pushing the climate continually in a single relentless direction of warming.

All of these influences must be considered cumulatively to determine the net impact.

Over the last 30 years of direct satellite observation of the Earth’s climate, many natural influences including orbital variations, solar and volcanic activity, and shifts in oceanic and wind patterns have promoted either stasis or cooling in the climate while human CO2 contributions have promoted warming.  Despite this natural opposition, global temperatures have continued to rise throughout this time period.

2010-08-25 18:05:03Nice
gpwayne
Graham Wayne
graham@gpwayne...
217.44.86.17

Good rebuttal - nice title too. I only have a few pedant's points to make:

"This combination of magnitude, duration, and cyclicity determines the impact of the influence on the climate system".

You explained the factors in the previous line, so this could be made simpler e.g. "The combination of effects and timings determines the impact on the climate".

"However, these changes occur over the course of thousands of years"

'the course of' is unnecessary. How about "However, these changes occur over thousands of years"?

"However, very few incidents of these events are of sufficient size to impact the global climate".- same here, what about "However, very few of these events impact the global climate".

"...alternating between promoting warming and cooling conditions" or "alternating between warming and cooling"?

"while human CO2 contributions have promoted warming" - a bit different, this might be more accurate if you said "while human actions have changed the climate". It isn't just CO2 and the effects are not just warming.

2010-08-26 05:08:46Emphasis on first sentence.
villabolo

villabolo@yahoo...
76.93.65.8

Deniers want to emphasize that there are other factors in "natural" climate change in an effort to confuse the issue of man made global warming being caused primarily by CO2. You should therefore emphasize a duality between "natural" and "man made" right from the start of your rebuttal. The sooner you make an important point like this, in just one sentence, the better it will stick in the reader's mind. The first sentence might read:

"Before the Industrial Revolution, our climate was driven by a variety of factors including CO2 but since Man started to burn fossil fuels in great quantities CO2 has become the single, major cause of our modern climate change." 

Some nit picking corrections:

For the sake of accuracy, continental drift could take millions of years for an effect on climate whereas the Milankovitch cycles need only tens of thousands of yeas. 

Volcanoes have had, at least on one occasion, a drastic and permanent effect on climate. They took us out of "Snowball Earth." 

VILLABOLO

 

2010-08-26 05:16:14
nealjking

nealjking@gmail...
91.33.112.139
I read somewhere that cumulative deforestation has done as much for GW as CO2. Might want to check that before posting any sweeping claims.
2010-08-26 07:24:18Comment
Robert Way

robert_way19@hotmail...
142.162.191.40
I don't know if saying that solar has a short cycle is a good thing. the sunspot cycle is short but there are many decadal, centennial, millenial and maybe even million year cycles we don't know about with respect to both solar and the oceans. It's a little hard to generalize like that unless you acknowledge the significant uncertainty with respect to those aspeccts
2010-08-26 09:34:52REVISION 1
Michael Searcy

scentofpine@yahoo...
72.91.223.97

Industrial CO2: Relentless warming taskmaster

SEE REVISION 4, DOWN THE PAGE

Natural processes have determined Earth’s climatic history, but human industrial activities have introduced a new forcing that is driving Earth’s climate future.

At any given time, the Earth’s climate is subjected to a myriad of natural influences.  These influences range from changes in the planet’s orbit around the Sun and shifts in continental tectonic plates to volcanic eruptions, variations in solar activity, and changes in wind and ocean patterns.  The climatic impact of each influence varies based on the magnitude of the natural change, the duration over which the change occurs, and whether or not that change is part of an overall repeated cycle.

Continual shifts in tectonic plates and cyclical changes in Earth’s orbit around the Sun can completely alter the face of the planet.  However, these changes occur over thousands of years.

Volcanic eruptions and impacts from celestial bodies, like asteroids, have an immediate and one-time influence.  However, very few of these events are of sufficient size to impact the global climate.

Variations in solar activity and wind and ocean patterns can have an influence over the course of months to decades, but they typically alternate between warming and cooling in accordance with their respective cycles.

The human industrial contribution of CO2 to the atmosphere is different.

This human CO2 influence is happening very rapidly, is not cyclical, and pushes the climate continually and unrelentingly in the single direction of warming.

All of these influences must be considered cumulatively to determine the net impact.

And over the last 30 years of direct satellite observation of the Earth’s climate, many natural influences including orbital variations, solar and volcanic activity, and oceanic and wind patterns have promoted either stasis or cooling in the climate.

Despite this natural opposition, global temperatures have continued to rise.

While natural processes continue to introduce variability from year-to-year, rising CO2 from industrial activities has become the dominant factor in determining our planet’s climate now and in the years to come.

2010-08-26 09:37:19
Michael Searcy

scentofpine@yahoo...
72.91.223.97
Thanks, all, for the comments.  Some really great recommendations.  I've taken a pass at a revision.  Let me know what you think.
2010-08-27 20:55:19Nice one
gpwayne
Graham Wayne
graham@gpwayne...
217.44.86.17
Hi Michael, looks good to me and time for a thumb. My only comment - more pedantry I'm afraid - is that perhaps there are a few sentences that could be put together into paragraphs. Worth a look if you have time?
2010-08-28 11:54:18
doug_bostrom

dbostrom@clearwire...
184.77.83.151

Might be worth throwing in this graphic (forcing components w/net anthropogenic contribution comparison):

 

http://www.ipcc.unibe.ch/publications/wg1-ar4/faq/fig/FAQ-2.1_Fig-2.png

I'm pretty sure this is already uploaded to SkS.

2010-08-31 23:59:35
PatriciaW
Patricia Warwick
forums@waremail...
64.231.19.93

I'd like to see "forcing" explained or dropped  - maybe " but human industrial activities have introduced a new mechanism that is driving Earth’s climate future."

I'd also reword the second sentence of the second paragraph ... "These influences include changes in the planet’s orbit around the Sun,   shifts in continental tectonic plates, volcanic eruptions, variations in solar activity, and changes in wind and ocean patterns."

Third paragraph: is "thousands of years" accurate? I'd say a larger order of magnitude but I'm not an expert in this area. But to completely change the face of the earth? - what about millions?

Fourth paragraph,  "However, very few of these events are of sufficient size to impact the global climate for more than a few years."

I'd also suggest combining a few of the following paragraphs. 

"stasis"? perhaps "Over the last 30 years of direct satellite observation of the Earth’s climate, many natural influences including orbital variations, solar and volcanic activity, and oceanic and wind patterns have either had no effect or caused some cooling. Despite this, global temperatures have continued to rise."

 

2010-09-01 01:17:24
Nicholas Berini

nberini@gmail...
24.189.119.236

Consistent with the image Doug suggested using, it may also be worth noting that CO2 is not even the only human driver of climate.  Land use changes, methane, aerosols, black carbon, and refridgerants are all examples of human 'forcings.'  CO2, however, has the largest effect and is growing at the fastest rate. 

2010-09-01 01:57:58
doug_bostrom

dbostrom@clearwire...
184.77.83.151

Just in case you should want to use it, I've uploaded the anthropogenic forcings graphic.

URL:

http://www.skepticalscience.com/pics/FAQ-2.1_Fig-2Forcings.png 

Anyway, this gets another thumb from me. 

2010-09-01 22:25:37REVISION 2
Michael Searcy

scentofpine@yahoo...
72.91.223.97

Industrial CO2: Relentless warming taskmaster

SEE REVISION 4, DOWN THE PAGE

Natural processes have determined Earth’s climatic history, but human industrial activities have introduced a new mechanism that is driving Earth’s climate future.

At any given time, the Earth’s climate is subjected to a myriad of natural influences, including changes in the planet’s orbit around the Sun, shifts in continental tectonic plates, volcanic eruptions, variations in solar activity, and changes in wind and ocean patterns.  The climatic impact of each influence varies based on the magnitude of the natural change, the duration over which the change occurs, and whether or not that change is part of an overall repeated cycle.

Continual shifts in tectonic plates and cyclical changes in Earth’s orbit around the Sun can completely alter the face of the planet.  However, these changes occur over tens of thousands to millions of years.  Volcanic eruptions and impacts from celestial bodies, like asteroids, have an immediate and one-time influence.  However, very few of these events are of sufficient size to impact the global climate for more than a few years.  Variations in solar activity and wind and ocean patterns can have an influence over the course of months to decades, but they typically alternate between warming and cooling in accordance with their respective cycles.

The industrial contribution of CO2 and other greenhouse gases to the atmosphere is different.  This human influence is happening very rapidly, is not cyclical, and pushes the climate continually and unrelentingly in the single direction of warming.

Additional human and natural factors like land use changes, carbon soot emissions, albedo variations, and halocarbons that are discussed in more detail in the Intermediate response also play a contributing role.

All of these influences must be considered cumulatively to determine the net impact.

Over the last 30 years of direct satellite observation of the Earth’s climate, many natural influences including orbital variations, solar and volcanic activity, and oceanic and wind patterns have either had no effect or promoted cooling conditions.

Despite this natural opposition, global temperatures have continued to rise.

While natural processes continue to introduce variability from year-to-year, rising CO2 from industrial activities has become the dominant factor in determining our planet’s climate now and in the years to come.

30-Year Climate Forcings and Lower Atmospheric Temperature 

Figure 1: Various climate influences from 1979-2010 and the corresponding temperature of the lower atmosphere.  All trends have been normalized.

2010-09-01 22:35:00
Michael Searcy

scentofpine@yahoo...
72.91.223.97

Once again, some great comments.  I've made another pass.  I'm reluctant to include the IPCC chart.  It gets a bit complicated for the Basic rebuttal requiring some detailed explanations, and it's covered in the Intermediate version, which also goes into some of the additional human influences.

I also included the graph and am interested to hear what people think.

I feel the primary reason people bring up this topic is to argue that humans are not the only influence on climate, so the primary focus should be on comparing natural influences to the dominant human influence.   The Intermediate level then takes it to that next level of granularity.

2010-09-02 01:02:16Comment
Robert Way

robert_way19@hotmail...
142.162.188.138
Michael,
we have to be careful with graphs like the one you are using there.


Firstly you are omitting the AMO which is ultimately one of the most dominate natural contributors there is. Secondly, I would suggest using RSS not UAH. RSS has a trend which roughly matches Hadley, GISS and NOAA whereas UAH is bizarrely much lower. I dont know if I would call it bizarre because christy runs it but either way I think its important to show the one which agrees the most with our measurements on the ground.

Also if you include those natural forcings then people will wonder why the North Atlantic Climate Pacemaker was not included as it measures the the strength of the THC. (we are of course still talking about the AMO). The AMO has undoubtedly contributed significantly to the post-1980s warmth. That does not mean that CO2 has not contributed but it just means it is a complicated issue.

Kerr, R. A., A North Atlantic climate pacemaker for the centuries,Science,2000: 5473), 184-1986.
2010-09-02 02:45:53
Nicholas Berini

nberini@gmail...
24.189.119.236

I know im repeating myself but how about: 

 

"The industrial contribution of CO2 and other greenhouse gases to the atmosphere is different.  This human CO2 influence is happening very rapidly, is not cyclical, and pushes the climate continually and unrelentingly in the single direction of warming."

 

I still feel that without mentioning that CO2 is not the only human driver there is something incomplete about this.  If youre looking for a simple but comprehensive figure, the one that John Cook posted into the comments section of this intermediate argument might fit the bill too. 

 

Finally could you give me the link/source for the figure you used??? Im particularly interested in it for the "cooling" PDO trend which I hadn't seen before - it would be very useful for the basic version im writing for the "its the PDO" argument.

Thanks! This is very close I think... 

2010-09-02 07:57:44
Michael Searcy

scentofpine@yahoo...
72.91.223.97

Robert,

I avoided the AMO for a couple of reasons.  I've heard many conflicting opinions as to its applicability in the global warming discussion (e.g., See the reply below from Dr. Eric Steig taken from the 1st comment in this 2006 RealClimate post).  I also stuck to the forcings that tend to be brought up most often and have corresponding arguments here on SkS (solar, PDO, ENSO).

[Response:I'm afraid that the idea that the AMO explains everything is pretty weak. Indeed, the evidence that the AMO is anything other than random noise (in constrast, for example, to ENSO), is pretty weak. In fact, the evidence that the AMO does anything is pretty weak. The AMO is a statistical description of climate phenomena. As far as I am aware, no one has made an even slightly compelling case that it is a physical phenomenon in and of itself, the way that ENSO is. Hence it is unpredictable, and very difficult to separate from other effects, like global warming. --eric]

Also, while I agree that the RSS record is in the greatest agreement with surface records, I picked the UAH record since it tends to be the poster child record of choice from the denialist community.  While it doesn't align as closely with GISS and HadCRUT, its definitively upward trend still establishes the main point of the article.  I'm happy using either one, though.

 


Nicholas,

I like your phrasing for the industrial contribution and have updated the post.  I'm still reluctant to get into too much detail of additional human (and natural for that matter) influences in the Basic response.  However, perhaps a specific call-out to the Intermediate version would be a good compromise.  I've updated the post with such a reference.

As to the PDO data source, there are a couple of options.  First, there is the WoodForTrees site which provides an awesome tool for plotting various trends.  You can plot several against each other as long as you normalize each data set.  Once plotted, the site also provides a link to the raw data used to generate the graph.  I used the normalized raw data for the PDO to create my own graph.  Alternately, you can go straight to the source at JISAO at the University of Washington and use it to generate your own graphs and trends.

2010-09-03 05:29:37Comment
Robert Way

robert_way19@hotmail...
142.162.188.138
Since that time when Steig responded there has been a lot of interesting research in the field with respect to the AMO. I have to respectfully disagree and I think many major climatologists would disagree with his opinion. The AMO is of course a physical mechanism. I could explain it in detail but here are a few papers that would do it better than me:

Chylek, P., C. K. Folland,
G. Lesins, M. K. Dubey, and M. Wang (2009),

Arctic air temperature change amplification and the Atlantic Multidecadal Oscillation
,Geophys. Res. Lett., 36, L14801, doi:10.1029/

A Hemispheric Mechanism for the Atlantic Multidecadal Oscillation
Journal of Climate Volume 20 (2006) October
MIHAI DIMA
GERRIT LOHMANN


Secular and multidecadal warmings in the North Atlantic
and their relationships with major hurricane activity
David B. Enfielda†,* and Luis Cid-Serranob‡

In summary, both of our attempts at replicating
the causality test have failed to convincingly reject the
hypothesis that the AMO affects global temperature
variability. This calls into question the premise implicit in
the analyses of Mann and Emanuel (2006) and Trenberth
and Shea (2006).


In fact David Benson did a multiple regression analysis using CO2 forcing and the AMO and found that 95% of decadally averaged global temperature anomalies can be explained by a regression of the two...

I do understand why you would include the PDO rather than the AMO because it is a greater talking point these days but there is an elephant in the room that we all have to acknowledge with respect to this stuff.


2010-09-03 05:36:27Comment
Robert Way

robert_way19@hotmail...
142.162.188.138
Also in the real climate glossary

Atlantic Multidecadal Oscillation (“AMO”)

A multidecadal (50-80 year timescale) pattern of North Atlantic ocean-atmosphere variability whose existence has been argued for based on statistical analyses of observational and proxy climate data, and coupled Atmosphere-Ocean General Circulation Model (“AOGCM”) simulations. This pattern is believed to describe some of the observed early 20th century (1920s-1930s) high-latitude Northern Hemisphere warming and some, but not all, of the high-latitude warming observed in the late 20th century. The term was introduced in a summary by Kerr (2000) of a study by Delworth and Mann (2000).




2010-09-04 00:01:18
Michael Searcy

scentofpine@yahoo...
72.91.223.97

Robert,

I agree that there has been an extensive amount of research into the AMO in the decade since its existence was postulated, particularly with regard to Atlantic hurricane impacts.  However, I still see many caveats related to it.

From RealClimate...

A multidecadal (50-80 year timescale) pattern of North Atlantic ocean-atmosphere variability whose existence has been argued for based on statistical analyses...

 

From the OOPC...

 

The Atlantic Multidecadal Oscillation (AMO) index reflects an argued 50-80 year pattern of North Atlantic coupled ocean-atmosphere variability.

 

From NOAA...

Is the AMO a natural phenomenon, or is it related to global warming? Instruments have observed AMO cycles only for the last 150 years, not long enough to conclusively answer this question. However, studies of paleoclimate proxies, such as tree rings and ice cores, have shown that oscillations similar to those observed instrumentally have been occurring for at least the last millennium. This is clearly longer than modern man has been affecting climate, so the AMO is probably a natural climate oscillation.

I also agree that it is a topic that has to be considered and discussed, but I think it's too much to take on within the context of this particular post.  Perhaps a blog post dedicated specifically to it?

While I like the graphic in that it shows in concrete terms that several of the natural trends have operated in opposition to the anthropogenic influence while temperatures have continued to rise, my inclination is to simply remove it if you feel it is going to generate more confusion than clarity.  I feel that including the AMO in the graphic is going to generate much more confusion in attempting to discuss the methodologies related to disassociating the AMO and anthropogenic signals while trying to clarify that the AMO can be considered responsible for "some but not all" of the warming in the last 30 years, particularly in the Arctic.

Let me know if you prefer to see the graphic removed or the AMO addressed via some additional verbiage.  If the latter, any drafts you can provide would be welcome.
2010-09-04 00:57:36Comment
Robert Way

robert_way19@hotmail...
142.162.188.138
I think it is just better to not include it but to have a short statement under the figure saying something like the AMO was not included because of the significant debate over its existence or something of the sort... Just as long as it is addressed thats all.

I understand why it would be perhaps confusing to include an AMO graph. For the record there is a tree ring study to be published sometime soon (I think at least because they did a presentation on it at the EGU in 2010) which shows the AMO has definitely occurred for the last 1200 years. In particular it shows an exceedingly positive AMO during the MWP and a negative one during the LIA and a small period where it shuts off during the LIA. Interesting stuff and shows how the THC really effects climate.
2010-09-04 13:55:32REVISION 3
Michael Searcy

scentofpine@yahoo...
72.91.223.97

Industrial CO2: Relentless warming taskmaster

SEE REVISION 4, DOWN THE PAGE

Natural processes have determined Earth’s climatic history, but human industrial activities have introduced a new mechanism that is driving Earth’s climate future.

At any given time, the Earth’s climate is subjected to a myriad of natural influences, including changes in the planet’s orbit around the Sun, shifts in continental tectonic plates, volcanic eruptions, variations in solar activity, and changes in wind and ocean patterns.  The climatic impact of each influence varies based on the magnitude of the natural change, the duration over which the change occurs, and whether or not that change is part of an overall repeated cycle.

Continual shifts in tectonic plates and cyclical changes in Earth’s orbit around the Sun can completely alter the face of the planet.  However, these changes occur over tens of thousands to millions of years.  Volcanic eruptions and impacts from celestial bodies, like asteroids, have an immediate and one-time influence.  However, very few of these events are of sufficient size to impact the global climate for more than a few years.  Variations in solar activity and wind and ocean patterns can have an influence over the course of months to decades, but they typically alternate between warming and cooling in accordance with their respective cycles.

The industrial contribution of CO2 and other greenhouse gases to the atmosphere differs from its natural counterparts in fundamental ways.  This human influence is happening very rapidly, is not cyclical, and pushes the climate continually and relentlessly in the single direction of warming.

All of these influences must be considered cumulatively to determine their net impact.

The graphic below depicts the 30-year trend and general climate influence over this period of several commonly discussed climate mechanisms.  Additional human (e.g., land use changes, carbon soot and halocarbon emissions) and natural factors (e.g., albedo shifts, methane emissions, AMO, volcanic activity) also play a contributing role. While not intended to be a comprehensive depiction of influences on Earth’s climate, it illustrates that the rise in our planet’s temperatures is occurring despite considerable opposition from multiple natural processes.

While these natural processes continue to introduce year-to-year variability, rising CO2 from industrial activities has become the dominant factor in determining our planet’s climate now and in the years to come.


30-Year Climate Forcings and Lower Atmospheric Temperature

Figure 1: Various climate influences from 1979-2010 and the corresponding temperature of the lower atmosphere.  All trends have been normalized.

2010-09-04 17:38:25Hmmm
gpwayne
Graham Wayne
graham@gpwayne...
81.152.234.172
Anyone else think this has got too complex?
2010-09-05 05:45:38REVISION 4
Michael Searcy

scentofpine@yahoo...
72.91.223.97

Industrial CO2: Relentless warming taskmaster

Natural processes have determined Earth’s climatic history, but human industrial activities have introduced a new mechanism that is driving Earth’s climate future.

At any given time, the Earth’s climate is subjected to a myriad of natural influences.  The impact of each influence varies based on the magnitude of the natural change, the duration over which the change occurs, and whether or not that change is part of an overall repeated cycle.

Processes that have historically altered the face of the planet, like cycles in the Earth’s orbit around the Sun or shifts in continental tectonic plates, occur over tens of thousands to millions of years.  While not nearly as dramatic, the influence of solar, ocean, and wind patterns is much more immediate, but these effects generally alternate between warming and cooling over the course of months to decades in relation to their respective cycles.  Volcanic eruptions and impacts from celestial bodies, like asteroids, have a near instantaneous effect, but very few of these one-time events are of sufficient size to impact the global climate for more than a few years.

The industrial contribution of CO2 and other greenhouse gases to the atmosphere differs from its natural counterparts in fundamental ways.  This human influence is happening very rapidly, is not cyclical, and pushes the climate continually and relentlessly in the single direction of warming.

All of these influences, along with additional factors like land use changes, carbon soot and halocarbon emissions, and albedo variations, must be considered cumulatively to determine the net impact.

Over the last 30 years of direct satellite observation of the Earth’s climate, many natural influences including orbital variations, solar and volcanic activity, and oceanic conditions like El Nino (ENSO) and the Pacific Decadal Oscillation (PDO) have either had no effect or promoted cooling conditions.

Despite these natural oppositions, global temperatures have steadily risen throughout that time.

While natural processes continue to introduce short term variability, the unremitting rise of CO2 from industrial activities has become the dominant factor in determining our planet’s climate now and in the years to come.

2010-09-05 05:47:11
Michael Searcy

scentofpine@yahoo...
72.91.223.97
Obviously, the graphic was becoming more trouble than it was worth.
2010-09-05 18:42:23Which thousand words
gpwayne
Graham Wayne
graham@gpwayne...
81.152.234.172
Michael, I have to concur. This is one time when the 'thousand words' were not really required. Your text does the job admirably in my view...
2010-09-09 01:33:22
doug_bostrom

dbostrom@clearwire...
184.77.83.151
If one of these articles languishes for too long, do we get to vote again?
2010-09-09 04:01:24OK
nealjking

nealjking@gmail...
84.151.34.204
OK, go for it.
2010-09-10 13:51:55Comment
Robert Way

robert_way19@hotmail...
142.162.205.242
Haha it won't languish
2010-09-10 19:26:46
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.210.213
Glad you got rid of the graphic. Like the title, very catchy. 
2010-09-11 00:19:10Miscellaneous suggestions
James Wight

jameswight@southernphone.com...
58.105.164.221
I haven’t read through the entire thread (I’m late to the party as usual), but here are my comments on revision 4:

There are a couple of places where I suggest you simplify your language:
•    Change “an overall repeated cycle” to “a repeating cycle”
•    Change “oceanic conditions” to “oceanic cycles” (because you use the word “conditions” twice in the same sentence)
•    Change “natural oppositions” to “opposing natural forces”

Also, it’s not a huge deal, but you do make it sound kind of like CO2 has never been a driving cause of climate change before. For instance, it happened 55 million years ago and resulted in a marine mass extinction. CO2 has also played a part more recently as a feedback in the Quaternary glacial/interglacial cycle.
2010-09-11 07:12:01Basic dRebuttal #101: CO2 not only cause -- thumbs up
jimalakirti

jimalakirti@gmail...
71.34.142.115
Green thumb for CO2.
2010-09-11 19:46:21Published
John Cook

john@skepticalscience...
121.222.93.62

Probably right that the graphic is too complex for the basic rebuttal. But it's a fantastic pic and would make a great infographic. Michael, would you mind doing a separate blog post featuring this graphic, perhaps with some explanatory text. Good graphics are gold in science communication.

Can I suggest you rejig it so rather than having pics side by side, you have them one after the other to show them larger? Perhaps a heading like "The drivers of climate" - something clear, easy for people to understand. It would be a great graphic that I can see other websites using also.