Matthews and Caldeira on the Mitigation Challenge

February 28th, 2008

Posted by: Roger Pielke, Jr.

Just when you thought that the mitigation challenge was dismal, Matthews and Caldeira publish a paper in GRL suggesting that things are in fact worse than that:

In the absence of human intervention to actively remove CO2 from the atmosphere [e.g., Keith et al., 2006], each unit of CO2 emissions must be viewed as leading to quantifiable and essentially permanent climate change on centennial timescales. We emphasize that a stable global climate is not synonymous with stable radiative forcing, but rather requires decreasing greenhouse gas levels in the atmosphere. We have shown here that stable global temperatures within the next several centuries can be achieved if CO2 emissions are reduced to nearly zero. This means that avoiding future human-induced climate warming may require policies that seek not only to decrease CO2 emissions, but to eliminate them entirely.

Have we mentioned that air capture is coming? And that is whether we like it or not.

8 Responses to “Matthews and Caldeira on the Mitigation Challenge”

  1. lucia Says:

    “We show first that a single pulse of carbon released into the atmosphere increases globally averaged surface temperature by an amount that remains approximately constant for several centuries, even in the absence of additional emissions.”

    This is news? Unless the single pulse of carbon is sucked out somehow, yes, you get a rise, and then the temperature remains constant.

    That’s precisely what one would predict from the over simplfied IPCC equation for an isothermal earth. (That is solve
    T= T’/lamda + f using a step funciton for f.)

    You’ll get a answer that’s a bit different for a more complicated model– but qualitatively, the simple model captures *this* dynamic.

  2. 2
  3. Mark Bahner Says:

    “However, human-induced climate warming will continue for many centuries, even after atmospheric CO2 levels are stabilized.”

    I’m reading Joseph Romm’s unintentionally hilarious “Hell and Highwater.” He *routinely* makes prophecies about how humanity will suffer, “…for the next 50 generations.”

    One can only marvel at someone who thinks he can see 1000 years into humanity’s future!

    Simply think of the silliness of someone in 1908 saying how things would be in 2008. Let alone someone in 1808 or 1708 saying how things would be in 2008.

    And as Ray Kurzweil points out, change is accelerating.

  4. 3
  5. Roger Pielke, Jr. Says:

    I see over at Grist Joe Romm also discusses this paper:

    Notice how he doctored the same quote that I shared to remove the reference by Matthews and Caldeira to “[e.g., Keith et al. 2006], which is a paper on air capture.

  6. 4
  7. David B. Benson Says:

    There are many geological and astronomical ‘events’ which can be predicted for millions of years into the future. It appears that some geochemical ‘events’ can also be predicted, albeit with less accuracy, under the assumption that humans do not sequester any of the carbon currently in the active carbon cycle.

    It is a matter of predicting, assuming ‘if this goes on’. This is usually informative for policy.

  8. 5
  9. lucia Says:

    What happens if we leave the existing CO2 is informative.

    My first comment was simply, how is it the information “new”? We know the basic way GHG’s work. If you put them in, they warm until you take them out.

    But, the fact that they work this way means that if we wish to reverse the effect, we need to develop and implement technologies to sequester the CO2.

    Funding should be be provided to develop these types of technologies, and any ancilliary technologies that might be required to supply the extra energy needs that are generally required to power any particular sequestration technology.

    Sompe proposed methods require lots of energy. If they do, then energy from nuclear materials will likely be required to effectively implement these sequestration policies, or work. This would mean we should be funding research to provides us better choices for nuclear energy.

    There aren’t infinite choices.

  10. 6
  11. TokyoTom Says:

    Roger, thanks for posting this and the link to your 2005 post. However, I’d have to say I disagree with these earlier conclusions:

    “If such a transformation occurs, then we have the irony of seeing the climate skeptics become the technology advocates and the greenhouse gas regulation advocates become technology skeptics. Why? For most of those people who support greenhouse gas regulations, even admitting the possibility of air capture is anathema, because it would undercut the entire structure of the contemporary climate enterprise. Consider that the Kyoto Protocol and all of its complex mechanisms would largely be rendered irrelevant. So too would be most research on carbon sequestration (though point source sequestration would likely remain of interest) and management, as well as much of research on reducing emissions”.

    I disagree with this because, if properly structured, various types of mitigation efforts are entirely consistent. As long as international agreements create enforceable net GHG emission targets, this will establish pricing emissions of GHGs and soot. Wise domestic implementing policies will be neutral to how net reductions are achieved, and should allow offsets for carbon capture and storage, including atmospheric capture.

    While initial policies may focus on emission reductions, the pricing pressure will naturally create incentives for individual firms to invest in technology to capture and sequester their own GHG emissions, which technology they will of course market.

    In addition, politicians being who they are, it is likely there will be some government funding for CCS investments, and political pressure will certainly to allow the country to reduce net GHG emissions on a least-cost basis by allowing offsets from carbon capture as well as from emissions reductions.

    I think you are closer to being right when you are talking about a reluctance of those in favor of government action to embrace deliberate geoengineering to mitigate GHG emissions.



  12. 7
  13. TokyoTom Says:

    Lucia, allow me to disagree with you here:

    “Funding should be be provided to develop these types of technologies, and any ancilliary technologies that might be required to supply the extra energy needs that are generally required to power any particular sequestration technology.”

    If the government gets affirmatively involved in making or subsidizing particular technology investments, it is guaranteed to be wasting tax dollars that could be better spent by the private sector.

    The government should simply allow offsets for CCS and let the market/private investors choose what, if any, technologies provide the biggest bang for the buck.

  14. 8
  15. David B. Benson Says:

    Tokyo Tom — I think you will find that government investments in new technology has paid off quite handsomely. R & D is risky. Who is going to bear the risks and enjoy the rewards (if any)?