More on soaring carbon concentrations

The important new study, “Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks,” that we blogged on earlier is now available online (tip o’ the hat to John M). You can get the abstract here and download the full study here.

bas_thumb1.jpgWhat carbon sinks are saturating? A recent and persistent increase in winds (photo, British Antarctic Survey) “over the Southern Ocean, caused by greenhouse gases and ozone depletion, has led to a release of stored CO2 into the atmosphere and is preventing further absorption of the greenhouse gas”(original Science article here).

Let me quote one key, sobering paragraph from the new study:

Growth in Atmospheric CO2. Global average atmospheric CO2 rose from 280 ppm at the start of the industrial revolution (circa 1750) to 381 ppm in 2006. The present concentration is the highest during the last 650,000 years and probably during the last 20 million years. The growth rate of global average atmospheric CO2 for 2000–2006 was 1.93 ppm. This rate is the highest since the beginning of continuous monitoring in 1959 and is a significant increase over growth rates in earlier decades: the average growth rates for the 1980s and the 1990s were 1.58 and 1.49 ppm respectively.

What is particularly novel about this Proceedings of the National Academy of Sciences paper is that the authors provide the first quantitative explanation I have seen for this accelerated growth rate:

The growth rate of atmospheric CO2 depends on three classes of factors: global economic activity (generated from the use of fossil fuels and land-use change), the carbon intensity of the economy, and the functioning of unmanaged carbon sources and sinks on land and in oceans. Since 2000, a growing global economy, an increase in the carbon emissions required to produce each unit of economic activity, and a decreasing efficiency of carbon sinks on land and in oceans have combined to produce the most rapid 7-year increase in atmospheric CO2 since the beginning of continuous atmospheric monitoring in 1959. This is also the most rapid increase since the beginning of the industrial revolution.
We estimate that 35% of the increase in atmospheric CO2 growth rate between 1970–1999 and 2000–2006 was caused by the decrease in the efficiency of the land and ocean sinks in removing anthropogenic CO2 (18%) and by the increase in carbon intensity of the global economy (17%). The remaining 65% was due to the increase in the global economy.

The longer we delay, the deeper we will have to cut emissions to stabilize concentrations, especially because the carbon sinks are saturating.

The study’s lead author, Dr Pep Canadell, executive director of the Global Carbon Project, explained “Fifty years ago, for every tonne of CO2 emitted, 600kg were removed by natural sinks. In 2006 only 550kg were removed per tonne and that amount is falling.”

The authors, from the Global Carbon Project, have put online a great PPT presentation here. Kudos to the GCP for their work.


8 Responses to More on soaring carbon concentrations

  1. Paul K says:

    If CO2 levels are rising at ever more alarming rates, why has there been no warming trend since 1998? The 1975 – 1998 warming trend was caused by increased CO2 in the atmosphere. That is settled science. Why has the trend not continued with even greater concentrations? Where are the rising sea levels? Have they gone up even six inches in the last ten years? On a less combative note, last week I took a trip through Iowa, South Dakota and Montana. There’s a lot of wind power up and running and more coming in this region. The wind turbines are a magnificent sight from the highway.

  2. Dano says:

    Fer chrissake. That ‘1998’ canard was refuted and put to rest long ago. Why do denialists keep recycling it? Oh yes: because that’s all they have. Never mind.

    Joe, one caution we should take is this is a single paper. I’d like to see some more confirmation before it is trumpeted all over the place. Of course it makes sense and may be robust, but more careful wording plz.



  3. Paul K says:

    A canard is a false statement. A fact is the truth. The fact is 1998 represents the high point in global warming. A prominent climatologist recently said the warming won’t restart until 2010. We’ll soon see if it does.

  4. Emmeline says:

    this is really helpful >

  5. Tim says:

    Voracious reader, first time poster.
    @ Paul K.


    Cherry picking single datum points much?


  6. raig Allen says:

    Paul K:

    The global temperature trend is characterised by a long term warming trend with year to year ‘noise’ imposed over the top. If you look at plots of the data you can identify a dozen temporary dips of several years or more that temporarily interupt the upward trend.

    This ‘noise’ is due to factors such as the el nino, indian ocean dipole and numerous other aspects of the climate system.

    If the noise in the climate record were to disappear all together and we were to start seeing a relentless year by year increase, that in itself would be very wierd and scary. It’s not going to happen.

    The trend will continue, the World will get warmer, the records will be broken every few or dozen years, and temporary dips will occur again. And presumable people desperate to deny the reality we are facing Cwill continue to pretend black is white and up is down.

  7. ED says:

    Paul, just as some don’t understand the difference between “Weather” and “climate” you are confused between two very different things, “the year that is the current record holder for average global temp for the year” is one thing (and is a statistical tie between 1998 and 2005, if you research it more carefully) but even if it was “1998” that’s very different from “The trend has stopped the increase” in which one can look at the rolling averages in 10 or 20 year periods, among other ways of looking at “trends” (this doesn’t even begin to touch on issues like the built in extra heating already in the pipeline

  8. J4zonian says:

    or, Ed,

    the global heat sinks of ocean acidification, and melting ice, which absorbs heat as it changes phase and prevents, temporarily, temperature increase.

    And Joe, as much as I’m willing to keep on banging away at the same dense denialist heads month after month after month, refuting nonsense and correcting ‘mistakes’, the more articles you print on practical solutions (wind, solar, conservation, carbon tax, etc.) and political strategies, the better able we will be to move ahead, while, as necessary as it seems to publish some updates and denialist-debating rehashes, the more we feel we have to prove anthro. etc. climate catastrophe exists the more powerless we seem, and the more we and the articles all become lightning rods for the fulltime professional bloggers and their enthralled minions.

    (I tried to make that sentence longer and less readable but just couldn’t. Hope you can follow it.)