Picking a Bone With Some Carbon Numbers

The following appeared earlier this month at Canadian Energy Issues:

It takes roughly 7.8 billion metric tons of CO2 dumped into the global air to increase the concentration by one part per million (according to the Carbon Dioxide Information Analysis Center at the Oak Ridge lab in Tennessee). One year ago the global concentration hit 400 ppm for the very first time. So for it to have gone from 400 to 404.65 ppm means we humans have, collectively, in the space of a single year, dumped 36.27 billion tons of the stuff into our air.

I see two possible issues with this.

First, it makes the assumption that the increase in carbon concentration is completely due to human activity. There are other sources of CO2 emissions, e.g., respiration, decay, volcanoes and ocean diffusion.

Second, it does not appear to take into account any CO2 sequestration that may be happening.  The oceans are currently a net absorber of CO2. Plants absorb CO2.

Is it true that all other sources and sinks of CO2 balance so that any net change in atmospheric carbon is due to an increase or decrease human “dumping?”

What am I missing?

Quote via The Next Big Future and which quoted this paragraph without question.

NB: I am not questioning the idea that humans are having a negative impact just the numbers.  We humans need to quite fouling our nest!

4 thoughts on “Picking a Bone With Some Carbon Numbers”

  1. Natural absorption exceeds natural emissions. But atmospheric concentration keeps rising (see the Scripps Keeling Curve site; link below). Therefore the rise must be due to anthropogenic emissions.

    Also, while the atmospheric CO2 is increasing, atmospheric oxygen is decreasing. Why? Because when we burn carbonaceous fuel, we take the “free” oxygen from the atmospheric and lock it into CO2.

    Keeling Curve:

  2. Steve Aplin—

    Thanks for the response and the pointer.

    RE:Natural absorption exceeds natural emissions.

    1) That was part of the point I was raising. If natural absorption exceeds natural emissions then the the anthropogenic number must be even higher than you report.

    2) Looking at the 800,000 year graph it appears that the relation between natural absorption and natural emission changes constantly.

    By the way, I do plan to come back to Canadian Energy Issuesto read more of material.read more of your

  3. The anthropogenic numbers are indeed higher. Humans are emitting 30 billion tons a year, and concentration is rising by 2 ppm a year (the equivalent of about 15 billion tons). According to SkepticalScience (link below) this means natural absorption is greater than natural emission.

    Yes, the 800K year concentration shows natural fluctuations. Notice though that the maximums during that period approached 300 pmm. At no time except since 1700 has it ever gone as high as 400 ppm.


  4. Steve Aplin, thanks for the Skeptical Science Link. It looks like it will be a big help in answering some of my questions on this.

    Agreed regarding the 800K record showing nothing above 300 pmm until 1700. Older records, of course, show maximums substantially higher.

Comments are closed.