Friday, October 11, 2013

The Carbon Deit

Maybe its time we got back
to the basics of life
    Waylon Jennings ("Luckenbach Texas")

I'm all lost in the supermarket, I can no longer shop happily 
I came in here for that special offer, guaranteed personality 
   -The Clash


   I've been reading "Requiem For a Species" by Clive Hamilton, the Australian philosopher ( and author of "Affluenza")..    I'm only half way through, but already I found a nice explanation of what it would take to to stay on our carbon budget.

  As we all know the IPCC has embraced the notion of a carbon budget - a total amount of carbon that may be emitted over a period - as opposed to a " x by 2050" approach - which emphasized the emissions on the last year of the period.

  What IPCC has not told us,  is what it would take to get there.    We only know that the amount of carbon emissions must peak in the near future, and decline thereafter.  But the details are not yet available.

 But, happily, thanks to Hamilton, we can get a reasonable idea of what it might look like.  Hamilton spends several pages explaining the reasoning in the Anderson and Bowes paper. Reframing The Climate Challenge. (2010)  (21 page PDF)

      The logic is straightforward.  First determine how much carbon will continue to be emitted due to deforestation.  Second how much for agriculture.  The rest is what is left for Industry  (and driving around buying stuff).

     The authors use some optimistic, but not crazy,  assumptions.   Deforestation, which currently accounts for 12-25% of emissions, would peak in 2015 , and fall to zero by 2060.  Agriculture, which is responsible for methane and Nitrous oxide, accounts for about 25%  of global warming gasses.  They assume this will peak in 2015 and fall to about 1/2 of the current levels in 2050 and remain stable thereafter.

    What's left is industry,  commerce, (and driving around looking for a parking place).    They make several key assumptions.  One is that world emissions peak in 2020 and total emissions decline by 3%.  Deforestation and agriculture are not declining fast enough, so the industry et al, has to decline by 4%.   In addition, they assume that the "developing" world will not agree to the same peak  as the "developed" world.  Therefore they conclude that the rate for the developed world will be  6-7%.

 Here are some nice pictures from Shrink That Foot Print:

Emissions growth rates   


 So that's it.     There are lots of ways to get there, most of them heavy on theory.  In practice, the only time in recent history such declines have been seen was the 1990's when the USSR fell.  Their emissions declined by 5% per year.  The economic activity also declined  by 50% (1989-1996).   

   Naturally that's not the way we want to do it.  We want to grow population (P), to grow affluence (A), but reduce impact (I),  and we know that I=PAT, so that means the only way out is!     Hooray!  Everybody loves technology!    "There's an app for that"!   

     Here's an example, that shows how it works, from  "Determinant of Emmisson s Growth in OECD Counties" by Hamilton and Turton.   Between 1982 and 1997, in the rich countries,  population grew by 10%, affluence grew by 40%, but technology reduce emissions per unit by 30%.  The result?  a 10% increase in emissions.   

 This may help explain why, despite great strides in "efficiency" , we haven't made much progress on carbon to date.

     So we just need to improve our carbon per unit of GDP.    Really fast.  Not merely by the 6% per year needed to reduce carbon emissions.  But also by an additional factor to account for increasing population (P) and Affluence (A).    Just in case you are interested the UN expects population to increase at a rate of .75% per year between now and 2050.  And according to the Stern Report,  affluence is expected to increase at a rate of 1.75% per year.    

    So, memo to all you technologists working in your garages.  Start tinkering!

Which once again leads me to ask the question - "Can we be both affluent and sustainable?"

Or maybe we need to stop shopping?


Here's a handy guide to the carbon diet, complete with graphs from Shrink That Footprint


22 years till we blow the 2°C Carbon Budget

If global carbon emissions continue to grow as they have in the last decade we will burn through the 2°C carbon budget by 2035.  If we don’t begin aggressive reduction immediately, we will burn through the budget at some point soon enough.
That is the grim reality of extending historical emissions growth into the IPCC’s cumulative carbon budgets.
In its new report the IPCC stated that to have an even chance of limiting warming to less than 2°C (since the period 1861–1880) it will require keeping cumulative CO2 emissions from all anthropogenic sources to less than 840 GtC.
By 2011 mankind had already emitted 531 GtC.  (See our carbon emissions and sinks piece)
If global carbon emissions continue to grow at 2% each year, as they have done over the last decade, we will blow through the 840 GtC carbon budget at the start of 2035.
Global carbon budget
The more stringent target of 800 GtC, that gives us a 66% chance of limiting warming to 2°C, is exhausted in 2032.  The more lax goal of 880 GtC, that gives us a 33% of limiting warming to 2°C, follows shortly afterwards in 2037.  If non-CO2greenhouse gas concentrations increase, aerosols are reduced or the permafrost begins to melt these dates will be dragged forward.  The reverse will push them back.
Our current emissions path will leave us committed to more than  2°C of warming in just 22 years.  It would also commit us to much more warming beyond that given the economic inertia of global carbon emissions.
In fact the 2°C carbon budget is so stringent that even if global carbon emissions stopped growing and remained flat for the coming decades we would still break the 2°C budget in 2041, less than 30 years from now.
Emissions growth rates
In the graphic above we show the speed at which we exhaust the 2°C  budget based on different annual emissions growth rate scenarios.
The first one is the same as our initial chart and shows that if emissions grow at 2% each year we break the 2°C budget in 2035.  In the second we see that if annual emissions remain constant at a 2011 level we break the 2°C budget in 2041.  The third shows that if annual emissions decline at 2% per year we will break the 2°C budget in 2058.
To reach 2100 within the 840 GtC budget (>50%) emissions need to decline at 3.5% per year, beginning immediately.  If action is delayed until 2020 annual reductions of  6%/year are required.  Such reductions would be largely dependent on the deployment of negative emission technologies.
The gap between where we are and where we need to be is enormous.
This is the nature of our problem:
Carbon Emissions Sources
We have a coal problem.  We have an oil problem.  We have a gas problem.  We have a deforestation problem.
And our lack of ambition in dealing with it is quite astonishing. 

Labels: , , , , ,


Post a Comment

Subscribe to Post Comments [Atom]

<< Home