Skip to main content

New research finds no increase of airborne carbon dioxide fraction in past 160 years

A report on says new research published in Geophysical Research Letters has found that the airborne fraction of carbon dioxide has not increased during the past 160 years or during the last five decades.

The new research also found that most carbon dioxide emiited by human activity does not remain in the atmosphere. It is instead absorbed by the oceans and terrestrial ecosystems. The findings reportedly show that only about 45 percent of emitted carbon dioxide stays in the atmosphere.

Many scientists researching the Anthropogenic Global Warming theory use climate models that assume the airborne fraction will increase. If it is not increasing then those climate models could render false data. In order to learn whether the airborne fraction was actually increasing, Wolfgang Knorr of the Department of Earth Sciences at the University of Bristol reanalyzed available atmospheric carbon dioxide and emissions data since 1850. 

Understanding of the airborne fraction of carbon dioxide seems essential in predicting any possible future climate change. Having accurate knowledge of whether that fraction is changing, or will change as emissions increase, would also appear to be necessary in order to make accurate predictions.

Are scientists claiming that increased levels of atmospheric carbon dioxide are causing a rise in temperatures now faced with the possibilty that their research is fundamentally flawed? If the airborne fraction of carbon dioxide has not increased in 160 years that could show that human activity has had little or no effect on temperatures.


  • Richard 4 years ago

    can you say "Last Nail In Global Warming's Coffin"?

  • lljames 4 years ago

    Very little increase in CO2 in the last 150 years? What was it like before the Industrial age? How much CO2 did we have before that time? Knorr is measuring data from an increase that remained almost constant for 150 years. However, Knorr never said that global warming isn't happening and he said, given that we have more time, doesn't mean you should not be in favor of carbon cap emission laws. Global warming is still a reality and it is something we should be doing now, because we don't want to sit around and think we can relax about it or we will find ourselves in a real crisis when its too late.

  • CBDunkerson 4 years ago

    "Scientists claiming that increased levels of atmospheric carbon dioxide are causing a rise in temperatures are now faced with the possibilty that their research is fundamentally flawed."

    No. You've apparently missed the difference between 'fraction' and 'total'. The total amount of CO2 in the atmosphere >has< increased from ~280 ppm to ~387 ppm. Higher concentrations of CO2 mean more infrared radiation is retained... ergo your statement above is simply incorrect.

    What Knorr concluded is that the 'atmospheric CO2 / oceanic CO2' fraction has not changed... because the amount of CO2 in the oceans has increased quickly enough to keep pace with the atmospheric increase. Other studies published in the past few months have found that the ratio HAS started to change, suggesting that the oceans are becoming CO2 saturated and thus that atmospheric levels may increase more quickly in the future.

    Time will tell, but this doesn't call CO2 induced warming into question at all.

  • Dr. Bill Stone 4 years ago

    Not only did Darren Pope completely misunderstand and misquote the information in the Science Daily article, he appears to have selectively not seen the accompanying “related article” with the title “Global Warming From Carbon Dioxide Will Increase Five-Fold Over The Next Millennium, Scientists Predict.” Consumers of global warming news beware- always check the primary source of information yourself. I have responded to many postings and often find my posts “rejected” or “awaiting acceptance” when I point out the funding many authors receive from oil industry lobbying organizations. Moreover, it is important to look at the credentials of the authors(s) to see if the have the background needed to interpret and critically evaluate a scientific article. Mr. Pope's published bio shows no such ability.

  • Darren Pope 4 years ago

    Dr. Stone: In reference to the scientists who are predicting a five-fold increase in global warming due to carbon dioxide, would you care to shed some light on the climate models they are using? Flawed models that show an assumed increase in the airborne carbon fraction? I have never claimed to be a scientist, which explains why that doesn't appear in my bio, but I have seen enough common sense evidence to be capable of making a common sense decision on what I believe. I am simply exercising my 1st amendment right to freely share my opinion. What amazes me is the number of people who dismiss everything that contradicts data supportive of global warming. It seems to always be written off as inaccurate, ignored, or simply explained away as not meaning what it appears to mean. I am also amazed at the attempts to malign anyone who holds an opposing view. For the record, I have never deleted or rejected any of Dr. Stone's posts.

  • Albert N. Milliron 4 years ago

    Good article keep up the good work

  • Dr. Bill Stone 4 years ago

    Mr. Pope:

    The data showing the progressive increase in the absolute amount of carbon dioxide can be found at The slope of this line will increase as China and Indian become even more significant contributors to man made atmospheric CO2.

    Now for some pie 101: a fraction is not an absolute amount. Half of a big pie is more than half of a small pie. Global warming responds to the absolute concentration of carbon dioxide (and other green house gases such as water vapor) in the atmosphere- not the fraction between atmosphere and ocean.

  • Darren Pope 4 years ago

    Dr Stone: You didn't respond to my earlier question, but here's another: If the amount of carbon dioxide in the atmosphere is indeed rising, and that is the direct cause of global warming, then why have temps been decling for the last decade?

    And if the airborne carbon dioxide fraction is irrelevant to the question of global warming as you suggest, then why bother including it in climate models? Why work under the false assumption that it is rising? It seems to me that this is another way of manipulating data to obtain a desired result. What would those climate models show if Knorr's research showing no increase were input into the climate models? I believe they may show something quite different.

    Once someone shows me conclusively that global warming is not only real, but caused by human activity I will stop questioning the research. Until then I am not willing to just shut up and fall in line with the teachings of the Church of Climate Change.

  • JiminMpls 4 years ago


    The study did NOT find that CO2 is not rising. If you honestly believe that, you have been thoroughly brainwashed.

    The same holds true for your claim that global temps have declined over the past decade. They haven't.

  • Darren Pope 4 years ago

    JiminMpls: I did not say that carbon levels are not rising. I simply reported the results of the study which clearly say that the airborne carbon dioxide fraction has not risen. You seem to be attempting to cloud the issue.

    As for your claim that temps are not declining, I have seen research that says they are in fact declining. This is my problem with global warming. Proponents of AGW completely dismiss every piece of contradictory research that comes to light. We are not to question the research that is supportive of the AGW theory, but we are supposed to ignore opposing research.

    All I have ever advocated is open, honest debate of the issue. Proponents of AGW have repeatedly attempted to shut down debate and ridicule those who disagree witrh them. This is why so many people are just not listening to you anymore. You get what you give.

  • JiminMpls 4 years ago

    Now you lie. Read the headlline. "New research finds no increase of carbon dioxide in past 160 years."

    The study does NOT say that there has been no increase in carbon dioxide, but YOU DID.

    So, that makes you a brainwashed liar.

  • Darren Pope 4 years ago

    Or it could be you who is the brainwashed liar. I'm just saying. I have limited space for headlines. The article is very clear.

  • ghonadz 4 years ago

    Another load of denier cult bullcryp. Mr Pope deliberately spun and misinterpreted the article from ScienceDaily and then lied about some supposed temperature decline. In reality, if you check the world average temperature records, in the last decade from 1999 to 2009, every year was warmer than 1999 except for the year 2000. Each of the last 12 years (1997-2008) was one of the warmest on record. Hard to see much 'cooling' there.

    From Wikipedia: Temperature record since 1880
    The website[1] of the National Oceanic and Atmospheric Administration contains detailed data of the annual land and ocean temperature since 1880.[2]

    Each of the last 12 years (1997-2008) was one of the warmest on record. These years could be the warmest years for the last several thousand years according to the temperature record, not just since 1880, but the most recent data is the most accurate.[3]

  • Rich 4 years ago

    This is an example of why scientifically illiterate people should not try to interpret articles for the public. I'll give Mr. Pope the benefit of the doubt that he is simply illiterate and not dishonest, but the article he describes does not say what he claims. There is no dispute about the fact that CO2 in the atmosphere has risen over the past 160 years. There is open discussion about how increased CO2 is partitioned between ocean and atmosphere. The CO2 level in the atmosphere is increasing; the level in the oceans is increasing. Let science drive your ideology; don't let ideology drive your science.

  • Darren Pope 4 years ago

    Thanks, Rich, for providing the perfect example of the type of personal attacks on skeptics that I have been describing. Thanks for also providing a perfect example of twisting words and attempting to malign those who question what you claim to be absolute, undeniable truth. My scepticism has nothing to do with ideology, it arose from the lies, deception and attempts to supress data by people like Al Gore. The report did IN FACT say that researchers were using climate models that assume the airborne fraction is rising. That will IN FACT yield flawed results. That is not my interpretation, it is FACT. Continuing to call those of us who are skeptics liars, idiots, and deniers may make you feel intellectually superior, but it doesn't make you right. It just makes you another drone in the Cult of Climate Change. There has not been one single piece of conclusive evidence that shows a direct link between temps and human activity. Not one. That is also a fact. Nice try.

  • Rich 4 years ago

    Mr. Pope,

    Your headline says: "New research finds no increase of carbon dioxide in past 160 years." That is not a factual statement. I did not call you a liar, an idiot or denier. I did call you scientifically illiterate, which is the most charitable interpretation of your headlines. Your headline suggests that you are confused between the carbon dioxide fraction and the amount of carbon dioxide. The amount of carbon dioxide has increased substantially during this period. Your headline says it has not. Since I assume that you are an honest person, and would not want to mislead anyone with your headline, the logical conclusion is that you are reporting on an article that you did not understand initially. If you understand it now, good, but you should correct the headline. That would be a more appropriate response than calling people like Al Gore liars.

  • Darren Pope 4 years ago

    If Al Gore isn't a liar then he is as illiterate about climate change as you claim that I am. At best he's a hypocrite. I could do several articles based on Gore's outright lies and pathetically inaccurate statements on climate change. The Earth's core temp is millions of degrees Farenheit? I could do several more on his lifestyle, a lifestyle that flies in the face of claims that human activity is causing a rise in global temps. Gore uses more energy in a month than 20 average Americans. He does not allow anyone who disagrees with him to challenge any of his claims and will not debate the issue. His claim that "the science is settled" is completely false. There is not at this time a scientific consensus. I encourage everyone to continue to question anyone who says otherwise.

  • Rich 4 years ago

    Calling people liars or bringing up irrelevant facts is not addressing the point. Are you willing to acknowledge that your headline is misleading?

  • Darren Pope 4 years ago

    Rich: If you had read my comments below you would've seen that I have already addressed the headline. I have very limited space for headlines. My intent was not to mislead anyone. The content of the article is very clear. If it makes you feel better I'll edit the headline. That won't change the facts that so many people who have posted comments have refused to address. I have asked very direct questions and none have been answered. All I get in response is personal attacks and complaints about the headline. This is my problem with the issue of AGW. Anyone who doesn't fall in line is attacked. Anyone who dares ask a question is ridiculed. But thanks for visiting my page.

  • Rich 4 years ago

    Thanks for changing the headline. It is much more accurate. Now to be really accurate, you should explain more clearly to your readers that the absolute concentration of carbon dioxide has increased during the last 160 years.

  • Darren Pope 4 years ago

    No problem Rich. The subject of the article is the report on about the research by Dr. Knorr. Some of the comments here say that the fraction is irrelevant to the issue of climate change. I find that hard to believe. One of my questions is this: If the fraction is irrelevant why then use climate models that assume it is rising when conducting climate research? Further, if the fraction is not rising, wouldnt't any results yielded by those climate models be inaccurate? No one seems willing to answer those questions. It seems many of the predictions about possible future climate change are based on those models. If the results are inaccurate that raises doubts. That is the point of the article.

  • Rich 4 years ago

    Some studies have shown a very slight increase in the carbon fraction. Assuming the current study is correct, that would affect how fast the rise in CO2 in the atmosphere will occur. Modelers make various assumptions about what the future CO2 concentration in the atmosphere will be. They cannot predict the results that political decisions, emerging industrial nations etc. might have on future concentrations of CO2. What they can tell you is what will happen if a given level of CO2 is reached. So you can run different assumptions: what happens if we met the Kyoto protocol levels, for example. In the absence of feedback mechanisms, doubling the concentration of CO2 in the atmosphere would increase the mean global temperature about 1.2 degrees C. There is strong evidence to suggest that there are positive feedback mechanisms that would boost the temperature 3 degrees C every time you double the CO2 concentration. The study you reference does not affect these findings.

  • Rich 4 years ago

    Additionally, your conclusion: "If the airborne fraction of carbon dioxide has not increased in 160 years that could show that human activity has had little or no effect on temperatures." is incorrect. The climate responds to the fact that the concentration of CO2 has increased to about 380 ppm from about 280 ppm.

  • DMS 4 years ago

    Just remember, kids. A scientist whose research is in some manner funded by an oil company is a sellout who will blithely commit scientific fraud to provide propaganda for his corporate masters. But a scientist who takes money from socialist politicians with a vested interest in promoting global warming hysteria is a dedicated seeker for the truth and a selfless crusader working for the benefit of all humanity. If you can remember that, you won't have to bother with the tedious business of evaluating a researcher's work based solely on its merits.

  • Darren Pope 4 years ago

    Well said DMS, well said.

  • DMS 4 years ago

    Proponents of anthropogenic global warming theory are suffering from a credibility gap. One way to reduce this would be for them to publicly abjure the use of treaties, legislation, taxation, and any and all other forms of violence as a means of addressing the alleged problems caused by hypothetical anthropogenic global warming. This would allow people following the debate to focus on the scientific questions rather than worrying about what neo-Luddite anti-technology and Marxist redistribution agendas might be driving anthropogenic global warming theory.

  • DMS 4 years ago

    Thanks, Darren. I'm a great advocate of separation of science and state. The reduction of climate science to a political tool is just the latest sorry example of what happens when politics is allowed to infect the scientific process.

  • Rich 4 years ago


    So let's discuss the science and leave the politics aside. Do you agree with me that Mr. Pope's conclusion that "If the airborne fraction of carbon dioxide has not increased in 160 years that could show that human activity has had little or no effect on temperatures" is not only erroneous but a logical non-sequitor?

  • Gabriel Atega 4 years ago

    Climate has changed due to human activity. However, it is the wrong human activity that they are pointing at. It is not CO2 that is the problem but the increase in water vapor in the atmosphere resulting from global deforestation. By continually reducing the area and volume of forests will accelerate the hydrologic cycle and bring up more water vapor into the atmosphere. The science should look more into this area of human activity.

  • Rich 4 years ago

    I just wanted to stop by to say that you now have the opportunity to take potshots at me as well:

    how-it-looks.blogspot dot com

    Gabriel: water vapor is an active topic of research. The main effect is that as the earth warms because of CO2, there is more water vapor in the atmosphere. That effect is complicated by cloud formation and MIE scattering.

  • Dr. Bill Stone 4 years ago

    Mr. Pope still has problems with fractions. First for some pie 101- half of a big pie is more than half of a small pie but the “fraction” is the same. The article Mr. Pope refers to addresses the distribution/fraction of carbon dioxide between the atmosphere and the ocean and does not dispute the data showing a rapid INCREASE in the absolute concentration of atmospheric carbon dioxide (see, the major driving force for global warming. This absolute amount of carbon dioxide will increase even further as China and India burn more fossil fuel. Moreover, the article in question does not state that this fraction will remain constant in the future. It is likely that the large scale melting of permafrost (now occurring) will cause a new release of the carbon dioxide as well as methane which is an even more powerful green house gas.

  • Darren Pope 4 years ago

    Sorry, Dr. Stone, I don't have a problem with fractions. And apparently you and other AGW alarmists don't have a problem with distorting facts. That's why no one is listening to you any more. A recent PEW poll shows climate change to be at the bottom of Americans' concerns. 2010 is the year that will mark the end of this issue. If there is any truth to the AGW theory it will be the lies, distortions, and the politicization of the issue by alarmists who are responsible for the fact that no one believes it any more.