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CO2 – Some facts, figures and outcomes

Posted on 3 June 2011 by Riduna

The largest source of increasing CO2 in the atmosphere since 1850 is from the burning of fossil fuels and vegetation, arising from human activity.  These emissions pose a threat to the survivability of all on the planet.  The following invites attention to the sources of CO2 emissions, some of their effects and measures which might be taken to enforce their reduction.


213 countries and territories are listed as emitting a total of 29.319 billion tonnes of CO2 in 2007.

52 countries, each emitting <1 million tonnes per annum, were responsible for 18.6 million tonnes (0.06%) of CO2 in 2007.

120 countries, each emitting <100 million tonnes per annum, were responsible for 2.683 billion tonnes (9.15%) of CO2 in 2007.

41 countries, each emitting >100 million tonnes per annum, were responsible for 26.618 billion tonnes (90.79%) of CO2 in 2007.

Fig. 1. The ten largest emitters were responsible for 76% of total anthropogenic emissions in 2007.

CO2 emissions into the atmosphere are increasing at a rapid and accelerating rate and are now at their highest level in 15 million years.

The Big Five: China, USA, India, Russia and Japan each emit over 1 billion tonnes of CO2 per annum. Their total emissions in 2007 were 16.781 billion tonnes, over 57% of anthropogenic emissions.

China and the USA are the largest emitters of CO2.  In 2007 they emitted 6.538 and 5.838 billion tonnes respectively, over 42% of global emissions.

Neither country has committed to a reduction of their total emissions by 2020.

Both countries expect their emissions to rise for at least the next 20 years.

Japan emitted 1.172 billion tonnes of CO2 in 1990 and committed itself to reduce them by 20% or 237 million tonnes by 2020. By 2010 its emissions were 1.327 billion tonnes, an increase of 155 million tonnes or 13.2% on 1990 levels.

India expects its population to increase by 500 million over the next 20 years and its economy to rapidly expand. Consequently CO2 emissions are predicted to at least double, possibly treble over the next 20 years.

Russia significantly reduced its emissions in 1990 when it closed high polluting inefficient factories with collapse of the Soviet economy. Following the heatwave of 2010 which destroyed 20 percent of its grain crop and caused 50,000 deaths, it committed to reduce its 1990 emissions by 25 percent by 2020.  Achievement of this target is questionable.

Australia is the largest exporter of coal in the world.  Its 2008/09 coal exports were 261 million tonnes compared with production of some 70 million tonnes for domestic use.

Emissions from exported coal are over 3 times more than domestic emissions. Exported emissions are not recorded as Australian emissions but those of the countries in which the coal is burned.

Australia now emits more CO2 than France, a country with a larger more diverse economy and a population almost three times greater.

In 2008/09, major importers of Australian coal included Japan (104.8 million  tonnes [Mt], 39.8%), Korea (43.1 Mt, 16.3%), Taiwan (26.1 Mt, 9.9%), China (25.0 Mt, 9.5%) and India (24.7 Mt, 9.4%), all countries with significant and growing CO2 emissions.

Increased greenhouse gas emissions produce global warming and global warming causes increases in the level of greenhouse gases entering the atmosphere from slow feedbacks including:

  • Warming oceans.  As seawater gets warmer, its ability to absorb CO2 falls and the volume released by it rises, increasing the level of CO2 in the atmosphere.
  • Decaying organic material.   Vegetation and animal remains buried beneath frozen ground remain inert until the ground in which they are buried begins to thaw, resulting in their continuing to decay, releasing methane (CH4) into the atmosphere.
  • Melting of clathrate.  Methane clathrate is an ice like substance found beneath sea floor sediment in polar regions.  When melted by warming ocean water, it releases CH4 into the atmosphere at a rate of 168 litres per litre of solid clathrate.

  • Water evaporation.  As temperatures of the earths surface and atmosphere rise, surface water evaporates, increasing the level of water vapour (the most powerful of greenhouse gases) in the atmosphere.

Prior to 1750 the concentration of methane in the atmosphere was 0.7ppm but due to agriculture practices, mining and fossil fuel use is now 1.7ppm. In some parts of the Arctic it is nearly 2ppm due to melting of clathrates and permafrost.

Methane oxidizes to form CO2 over a period of ~15 years.  During this period  it is ~75 times more potent than CO2 as a greenhouse  gas.


Solar energy reaching the earths surface is radiated back into space as long wave (infrared) energy.  Greenhouse gases in the atmosphere, particularly CO2, absorb part of the solar energy radiated from the earths’ surface and emit some of it back to the earths surface – the greenhouse effect.  This is causing average global temperatures to rise, more so in temperate and polar regions than in the tropics. The more CO2 in the atmosphere, the greater the rise in average global temperatures.

Sea Level:  Ice sheets covering Greenland, East Antarctica and the marine ice sheet covering West Antarctica have begun melting at an increasing rate as a result of rising sea and atmospheric temperatures.  Hansen and Sato (2011) predict that the rate of polar ice loss could double every decade.

Consequently, sea levels are also rising at an increasing rate.  It is estimated that by 2100 this will result in average sea level rising by 0.8m – 2.0m though Hansen and Sato predict a rise of up to 5m.  Sea level rise of this magnitude will cause flooding of low coastal lands, especially coastal cities where over 70% of the world population lives and the most fertile river deltas used for food production.

Land ErosionAs a general rule, for each centimeter rise in sea level, coastlines will be eroded by 1m or by 100m in the event of a 1m sea level rise.  Coastal erosion of this magnitude will cause major damage to infrastructure such as roads, bridges, railways, airfields and to domestic, industrial and other buildings located on low-lying coastal land.

Fresh Water:  As average global temperatures rise, they cause land based snow and glaciers to melt more rapidly than they can be replaced. In other words, they melt at an increasing rate, reducing the amount of water they yield each year for dependent ecosystems and human agriculture.  The latter is now threatened.

Fig. 2. Overview on glacier changes since the end of the Little Ice Age. Glaciers and ice caps reached their Holocene (the past 10 000 years) maximum extent in most mountain ranges throughout the world towards the end of the Little Ice Age, between the 17th and mid-19th century. Over the past hundred years a trend of dramatic shrinking is apparent over the entire globe. 

Courtesy: Hugo Ahlenius, UNEP/GRID-Arendal.

In California competition for water between people and agriculture has resulted in unsustainable pumping of groundwater. Fresh water sources in coastal areas are being made salt as a result of rising sea levels.  By 2050 it is predicted that over half the estimated world population of 9.5 billion, will face water shortages.

Rainfall Changes: Climate scientists have long warned that rising air temperatures will increase water vapor in the atmosphere, change air flow patterns and precipitation in some areas. Increased rainfall is expected over tropical and high latitude areas with reductions occurring over the south-west and interiors of continents, the Mediterranean/Sahara and Central America.

For some parts this means drought conditions will persist or worsen (S.W. Australia,) while in others where rainfall has hitherto been adequate (the Amazon Basin, Zimbabwe), drought conditions may develop and become more frequent.  Regions with adequate rainfall may get additional precipitation causing flooding, damaging property and agriculture.

Climate Events:  As sea levels rise and air temperatures increase, the incidence of extreme or catastrophic weather events will increase and include destructive winds, drought conditions, heavy rainfall causing extensive flooding and high temperatures.

While there is little evidence that the 2010 Russian heat-wave or the Pakistan floods were produced by global warming, it is representative of extreme climate events which can be expected as world temperatures rise. 

Ocean Acidity:  As the level of CO2 in the atmosphere rises, the amount absorbed in colder seawater will increase, causing it to become more acidic. This reduces aragonite/calcites needed by marine animals to form shells – eg pteropods, corals, etc. and may reduce availability of iron required by phytoplankton.  Loss of these animals poses a serious threat to the marine food chain on which humans and other animals depend for food.

Species Extinction:  The rapidity with which climate changes are occurring threatens adaptive ability of some animal and plant species, both terrestrial and marine.  Hansen (2008) notes that species unable to adapt will go extinct.  They include those in a symbiotic relationship and those on which humans depend for food. 

It has been suggested that we are at the start of a 6th mass extinction.  This should be of concern to us since such an event affects our own ability to survive, particularly since it is occurring at a time when human population is reaching unsustainable levels.

Human Habitat: Serious threats to food crops on which a rapidly growing human population relies will arise from the above and attendant causes such as the spread of plant diseases, insects, other animal pests and, as experienced in Russia in 2010, agricultural losses from drought, heat and fire.

A combination of heat and humidity will kill an increasing number of animals, including homo sapiens, a species that can only survive a few hours in temperatures of 35°C and relative humidity >90%.  Sherwood et al (2010) predicts these conditions will develop and spread, progressively reducing human habitat as global temperature rises, killing many as it does so.


The main culprits and countries responsible for CO2 emissions are known.  The culprits are vested interests in the production and use of fossil fuels.  The effects of their action are known and best summarised as risking our socio-economic destruction in pursuit of short-term profits.

Primary responsibility for limiting their activities and ensuring that average global temperature does not exceed 2°C by 2100 is vested in national governments.  Those governments can and should be compelled to act responsibly by imposing a carbon tariff on national exports equivalent or related to the carbon emissions associated with their production.  In short, imposition of a global price on carbon.

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Comments 1 to 30:

  1. The Washington Post has an article that cites Skeptical Science.
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    [dana1981] Yep, they used my graph from the IEA CO2 emissions update.  Very cool!

  2. Hi Agnostic, very nice post. I understant the graph with the largest emitters refers to fossil fuel emissions, right? It does not include agriculture or land changes?
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  3. Thanks for assembling this. Lets note that this "... Hansen and Sato predict a rise of up to 5m." is not really a prediction of the high end. Unfortunately, under a business as usual scenario, there is no reason why sea level can't go up that high. In fact it is very likely to, but how soon? Unfortunately this can't be determined yet. By the way, if you are looking for consequences here's one.
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  4. Conclusion "Those governments can and should be compelled to act responsibly by imposing a carbon tariff " ( -Accusations of deception, fraud, dishonesty or corruption snipped- ).
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    [DB]  Please note that posting comments here at SkS is a privilege, not a right.  This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

    Please take the time to review the policy and ensure future comments are in full compliance with it.  Thanks for your understanding and compliance in this matter.

  5. Thanks Agnostic - a very informative post and a great place to send people who wonder what the fuss is about things getting a few degrees warmer. Thanks DB (and all other mods), once again. Pete - I believe that Hansen and Sato are speaking of the possibility of 5m by 2100: "BAU scenarios result in global warming of the order of 3-6°C. It is this scenario for which we assert that multi-meter sea level rise on the century time scale are not only possible, but almost dead certain." Pretty much everyone agrees that >10m becomes very likely on centuries or millennia timescales once Greenland and the WAIS pass tipping points that we may well already be close to.
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  6. Speaking of facts, figures and outcomes: Ain't Google swell? Looks like too much of a good thing...
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  7. While China is the world's greatest emitter of greenhouse gases (it took over that dubious distinction from the United States in 2006), the US ranks at the top of the GHG leader board in cumulative emissions since 1850, with the EU second. Between them, the US and the EU account for over 55% of cumulative emissions. China is a poor fourth at 7.6%, and India is further down the list at 2.2%. One of the more unfortunate aspects of dumping so much CO2 into the atmosphere is that for all practical purposes, it never goes away, i.e, "carbon is forever." University of Chicago oceanographer David Archer has stated that, "The climatic impacts of releasing fossil fuel CO2 to the atmosphere will last longer than Stonehenge, longer than time capsules, longer than nuclear waste, far longer than the age of human civilization so far."
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    [DB] Nice Archer quote.  Do you have a link?

  8. Cumulative emissions, and historical share, are red herrings. The Chinese have used this dodge since 2004, to avoid accountability for practices since the nature of the GHG-pollution threat was understood. Claims that China is taking the lead in 'green energy' is misleading to the point of false - the Chinese have tapped every form of energy available to the max as their economy grows as double-digit rates. And if there's a rush to suppress the coal pollution in China - get read for another 90s as the aerosl reduction cause a global temperature surge similar to the end of the Warsaw Pact economies. On the David Archer phrase, here's one link referring to it:
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  9. Thanks for the link. It originally comes from his book, The Long Thaw, as well as this Nature Reports piece. Included is this graphic, showing the "long tail" of CO2: Thanks again!
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  10. Moderator 4 "( -Accusations of deception, fraud, dishonesty or corruption snipped- ). " The featured article calls for political action... "Those governments can and should be compelled to act responsibly by imposing a carbon tariff " ...which implies governments are not currently acting responsibly (a political comment that is also an accusation in itself). My comment was only questioning the ethics of such a paradigm.
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    [DB] Certainly if you had added extra verbiage to clarify your comment in the first place than perhaps it may have been interpreted differently.  But you didn't.

    "My comment was only questioning the ethics of such a paradigm."

    If you were in a burning building and knew of a way out, would it be ethical to not tell the others in the building that there was a way out? 

    If somone had the choice to drink from two cups, and you knew that one contained a deadly poison and which one it was, would it be ethical to not tell them? 

    If you knew a bridge was out on a well-travelled road, would it not be ethical to alert the authorities and other motorists?  Even if it made you late for dinner?

    This thread is about the knowledge of a palpable threat to our and our descendants way of life (and our descendants very existence, should we do nothing), and what we can do personally and as a society to reduce the magnitude and repercussions of that threat.

    If you then interpret that as a call to political action rather than as a call for responsible societal action, that's an issue internal to you.

  11. Kudos to Agnostic for an excellent summary of AGW causes and effects.
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  12. Dan @ 6, Nice graph, but you are only looking at a little over 50 years of reasonably accurate CO2 recordings. A longer record would be more helpful. This would show how CO2 concentrations changed during the global temperature dips in the 1880’s & 1940’s (HadCRUT). Also you are presenting a graph where the global temp was moving up at a relatively constant rate. It would have been more interesting to note any changes in temperature during the brief CO2 rate dip, starting in 1988-1994.
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  13. Moderator (10) asks, "If you knew a bridge was out on a well-travelled road, would it not be ethical to alert the authorities and other motorists? Even if it made you late for dinner?" As it turns out, not more than two weeks ago, I was walking in the countryside and noticed a precarious situation due to a broken high-powerline support etc. I did go out of my way to alert authorities. This to simply answer your three questions, which have nothing to do with the ethical question I have addressed. The ethical question has to do with establishing a system where money is accepted as compensation for environmental damage. If CO2 emissions are in truth incompatible with our biosphere, they cannot be tolerated, as with any other forms of criminal activity. Normally, a society where you can buy the law is considered corrupt by most standards. continue... "If you then interpret that as a call to political action rather than as a call for responsible societal action, that's an issue internal to you." The question does indeed become political when society allows itself to perceive the issue as only a relative threat, in which case, there are any number of ways to be "responsible".
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  14. J. Bob"Nice graph, but you are only looking at a little over 50 years of reasonably accurate CO2 recordings. A longer record would be more helpful." Try this video, Time history of atmospheric CO2, which covers 800 Ky. Also, what dip of CO2 rates? There's some variation in the record, but no significant dip in the rate of CO2 rise.
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  15. Very nice post, Agnostic - hits all the high points in a good summary. Thanks. DaveW
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  16. Ja, but exactly how much is the cooling caused by CO2? What everyone forgot is that carbon dioxide also takes part in the life cycle. CO2 is taken up by the plants and the trees who then take warmth from their surroundings to grow. That is what you call an endothermic reaction. I noticed this when I happened to enter a forest at dawn = you could clearly feel that the forest was cooler and that it was taking energy from its surroundings. I mean did you ever see a forrest grow where it is very cold? Up until now, nobody, including the IPCC and all those more beautiful learned people, could put a figure to the cooling caused by the CO2 in this way. In fact, they had all forgotten about it. There are more issues like that.
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  17. 16 Mr OK "What everyone forgot is that carbon dioxide also takes part in the life cycle." Seriously? Gosh that's big news. Is this the outcome from one of Steve Mcintyre's analysis?!?
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  18. 16, Henry (sorry, I mean MoreCarbonOK), I followed your link... another flawed, falsehood laden bit of misdirection, I'm afraid. But please take your logic here through to its inevitable conclusion, something you clearly think "the IPCC and all those more beautiful learned people" were unable or unwilling to do, but you have the insight and courage to dare to try. Plants absorb sunlight (heat) and CO2 and convert the two into sugar (too bad all those so called scientists haven't figured this out, but you have). What happens next? Where does the heat that these plants have gratefully protected us from wind up? How is this magical floral cooling not merely initiated, but maintained? Please, teach us. We want to learn. To other readers: Please, please, please do follow all of Henry's links and see what he has to say. Learn to recognize and distinguish real science from "close enough, looks good to me if I just stop thinking here" no-where-near-science.
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  19. You say "The largest source of increasing CO2 in the atmosphere since 1850 is from the burning of fossil fuels ..." I ask what evidence you have that (a) such increases are larger than natural increases and (b) such increases are larger than increases due to deforestation which not only adds CO2 from burn-offs but also, far more so, from the resulting reduction in photosynthesis.
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  20. Carbonskeptic. The evidence is from carbon isotopes (not to mention some basic accounting). Deforestation is another anthropogenic change, but again the isotope data says fossil fuel more important. See this article for more detailed explanation and references to the science.
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  21. Carbon S#19 Here's evidence. van der Werf et al 2009: carbon emissions from deforestation and forest degradation have been estimated to account for about 20% of global anthropogenic CO2 emissions That appears to be an average; the most recent estimate shown in Figure 1 in that paper was for 2006: Deforestation ~1.5 Pg C/yr, fossil fuels ~7 Pg C/yr. It's good practice to substantiate one's commentary - especially if you're interested in building credibility.
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  22. 18, 20 & 21: I am not talking only about carbon emissions from deforestation and forest degradation. Plant life enhances the rate of photosynthetic sequestration, and thus a reduction in plant quantities will (other things being equal) reduce the amount of carbon dioxide taken from the atmosphere by plant photosynthesis. Fortunately, increased carbon dioxide in the atmosphere enhances plant life such that photosynthetic sequestration is also enhanced. There are a number of papers but this will do for a start. My point in 18(b) is quantified in the literature referred to in this summary. There it is calculated that anthropogenic fossil fuel emissions account for only about 20% of the total anthropogenic contribution. Hence mankind should be focussing on planting forests more so than cutting fossil fuel emissions. Take it or leave it. In my view the carbon dioxide has no effect on warming anyway.
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    [DB] "Hence mankind should be focussing on planting forests more so than cutting fossil fuel emissions. "

    Hence the need to actually read more of the literature on the subject.  Like that from scientist Ken Caldeira:

    Planting Trees Won't Help

    "In my view the carbon dioxide has no effect on warming anyway."

    Perhaps in your world then the radiative physics of anthropogenically-derived CO2 differs from that already in the carbon cycle.  How wonderful.  For those of us in this world it is a different story.  Please note that unsupported assertions lacking source citations are generally ignored or treated as spam.

  23. #22 CarbonSkeptic, it's hard to trust your assertions on deforestation when you're wilfully ignorant of the basic physical properties of the CO2 molecule. Perhaps on an appropriate thread you could explain to us us why the Earth has been liveably warm through geological history despite the Sun not presently provide enough incident radiation to keep Earth above freezing (without non-precipitable greenhouse gases), and even more so having been even fainter in the geological past?
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  24. 22 DB: I'm sorry, but whilst I did read the blog "Planting Trees Won't Help" I would prefer to believe peer-reviewed papers such as those quoted in the link I provided. I fail to see any quantification in your item. Also, I was talking about carbon dioxide levels, not the effect on temperature based on the relative colour of the trees or the amount of evaporation.
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    [DB] "I would prefer to believe peer-reviewed papers"

    Perhaps this or this by Caldeira, for starters.

  25. 23: I am very much aware of the physical properties of the carbon dioxide molecule and the quantum physics associated with it and other air molecules. I am also very much into heat transfer theory and thus understand the errors which, in effect, double count heat transferred from the surface. And, yes, I can explain Earth temperatures based on physics and the rates of heat transfer from the core to the surface and thence from the surface to space. In fact the calculations are within a couple of degrees of actual and do not relate to carbon dioxide at all. But you changed the topic and so, yes, I will answer elsewhere when I have the time.
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    [DB] "I can explain Earth temperatures based on physics and the rates of heat transfer from the core to the surface and thence from the surface to space."


    "In fact the calculations are within a couple of degrees of actual and do not relate to carbon dioxide at all."

    It is rather odd, one would think, that you share both the unsupported energy transfer/CO2 hypothesis' of Doug Cotton as well as certain other characteristics...

    "I will answer elsewhere when I have the time."

    We look forward to you supporting your assertions with links to cited sources found in the peer-reviewed literature...on the appropriate threads.

  26. CarbonSkeptic - If you think the current surface temperature is due to heat transfer from the Earth's core (as you seem to state in that post), I suggest you read Heat from the Earth’s interior does not control climate. If you feel that is the case you should comment there. It turns out that heat from the Earth's core is several orders of magnitude too small to account for Earth's current surface temperature. Whereas greenhouse gas effects are just about right.
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    [DB] I suspect our guest has much in common with Mr. Cotton.

  27. 24. DB: The Caldeira papers disregard the enhanced photosynthesis and its effect on carbon dioxide levels. These papers are talking primarily about temperatures, whereas my original point 19(b) was about carbon dioxide levels. Maybe readers should study the second link in 22 above and some of the papers listed at the foot thereof.
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    [DB] I am more widely read than is supposed.  Perhaps others will gain some insights into your position from this quote:

    "volcanic CO2 emissions are much higher than previously estimated, and as volcanic CO2 is isotopically identical to industrially emitted CO2, we cannot glibly assume that the increase of atmospheric CO2 is exclusively anthropogenic."

    Plant regrowth & sequestration of CO2 is also directly affected by precipitation levels, which are also affected negatively by rising temps.  The net effect is reduced transpiration and slowed forest regrowth.

    Edit:  CarbonSkeptic has since revealed himself to be a sock puppet iteration of Doug Cotton.  It is unfortunate that some feel the need to falsely portray themselves as others in order to advance an agenda of pretence and active disinformation.

  28. Hang on. If there is enhanced photosynthesis activity due to enhanced CO2, shouldn't such plants produce more oxygen as the by product of all this. The last I knew, oxygen was declining as a proportion of atmospheric gases. Not enough to affect oxyden dependent life forms given its superabundance, but enough to back up the analysis based on carbon isotopes.
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  29. It is unfortunate that SkS has to entertain even the most egregious nonsense for the sake of "balance" or to avoid accusations of censorship and what not. As a result, even the most severe cases of D-K must be tolerated. Perhaps some of the most extreme in this stuff should be dropped altogeher. I mean, really, there are things that are not matters of opinion, and questions to which there is one right answer. Sheesh...
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  30. DougCarbon#22: "point is quantified in the literature referred to in this summary" Sorry the anonymous webpage of a 'consulting geologist,' who refers to the discredited geocraft CO2 graph, is hardly 'the literature.' Apparently you missed the words 'forest degradation,' clearly referring to the reduced carbon uptake of stressed forests. "Take it or leave it. In my view" Yes, we may indeed take or leave your unsubstantiated opinion. That's about where we left off the last time we heard nonsense about the earth's core heat warming the surface - and that the sun does not.
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