Climate Imperative: lower natural gas

by Stephen Shafer on October 31, 2019

                                                 Climate imperative: lower natural  gas 

 CVE tractor

                                                         Tractor swarm Dover Plains NY  January 2019         

Qualitative summary Earth’s atmosphere handles methane and CO2 very differently.  It disposes completely (mostly by oxidation) of an inflow of methane within about ten years, but constantly renews  its stock of CO2 through the carbon cycle. So, where CO2 emissions must always add to atmospheric heat-trapping and thus to global heating,  methane emissions need not.   If annual methane emissions are just kept level year over year for a decade, their addition to heat-trapping will be  ZERO.  A steady decline in annual emissions over that period will allow cooling,  where even a steep drop  in CO2 emissions won’t.  

              The  Global Warming Potential  that  compares methane to  CO2  hides that crucial difference:  humanity  has leverage over methane’s future additions to heat-trapping that we don’t with  additions by  CO2.   As we strive to lower CO2 emissions,  we  must  exert our leverage on methane  by halting the annual growth of [mostly fracked] natural gas production,  now the chief driver  of  human-influenced methane emissions. To end  that  growth demands an abrupt cutoff of all new natural gas infrastructure.  Cricket Valley Energy, CPV Valley, Danskammer,  National Grid E37 Albany Loop and the Williams pipeline under NY Harbor (to name just five) must all be stopped in their tracks.  This is a climate imperative.

Quantitative summary  Suppose methane emissions in 2029 = 351 million metric tons (Mmt).  How much heat-trapping capacity will that add to the atmosphere?  Using GWP20 (global warming potential) of 86, the equivalent of 30 Gt (gigatons or billion metric tons) of  CO2,  almost as much as the   37 Gt  of actual  CO2 emissions in 2018.   THIS  CLIMATE  DEATH BLOW CAN BE AVERTED BY ACTION  STARTING NOW.  Here’s why:                                                                                                                                                        

             The atmosphere disposes of a year’s inflow of methane (mostly by oxidation) within about ten years, but constantly replenishes its stock of CO2 through the carbon cycle.  If methane emissions  over the next ten years  never exceed 351 Mmt/yr , that mass released in 2029 will add to the atmosphere the heating-up equivalent of  ZERO  mt  of CO2.   CO2 emissions always add; methane emissions need not.  In fact, steadily falling methane emissions will allow cooling to begin after ten years, where falling CO2 emissions will never.

                To keep methane emissions level 2019-2029, natural gas (NG) withdrawal and consumption must be held level; leaks and losses of methane from the NG supply chain are now the main source of human-influenced methane releases.   To end  all new natural gas  infrastructure  is a climate  imperative.  Come  2029,  do we want methane to add the heating equivalent of  30 Gt CO2 to  the atmosphere or the equivalent of  ZERO ?  “Therefore, choose life.”  Deut 30:19     

              Cricket Valley Energy, CPV Valley, Danskammer,  National Grid E37 Albany Loop and the Williams pipeline under NY Harbor (to name just five) must all be stopped in their tracks.     

           

Introduction  There are many good reasons to ban fracking.  Not always at the forefront among them  is that fracking has led  to a tremendous increase since  2006  in the withdrawal and marketing of natural gas (NG),  especially in the USA.   Total production rose by 62%  from 518 bcm in 2006 to 841 bcm in 2018.  In that time conventional went down by 58% and unconventional  i.e. “fracked” rose  by 273%.  Graph 1 .  The surge in  production of NG, which is about 93% methane,   causes increased emissions of the super-efficient greenhouse gas methane.

usnatgasgraph

      Graph 1.  Natural gas production in USA  by type (conventional vs. unconventional AKA  “fracked”) 2006-2018 in billion cubic meters/yr   source Rystad Energy

           GWP, (global warming potential)  says that a molecule of methane is 25 to 105 times more efficient at trapping heat in the atmosphere than a molecule of CO2.  From this fact, most people think that a one-ton emission of methane will always add to atmospheric heat-trapping capacity the equivalent (termed CO2-e) of 25 to 105 tons of CO2 released at the same time.  

            There,   most people are wrong.

            In all scenarios where methane emissions year-on-year have been flat (zero slope) or decreasing (negative slope) for about ten years, calculated CO2-e may be billions of  tons  yet the  year’s emissions will add nothing to atmospheric heat-trapping potential,  even let it decrease.  This is because the atmosphere disposes of a year’s methane inflows entirely over the next ten or so years while instantly replenishing its stock of  CO2 for centuries through  the carbon cycle.  

            To have reached  ten years hence  this zone of no future added heating from stable ongoing emissions will  not  end our methane crisis.   Atmospheric levels will be much  higher than today’s.  It is, however, a bend in the arc of methane’s contributions to heat-trapping capacity. The curve of  CO2’s additions, by contrast,  will always rise  until emissions are zero.  People fighting fossil fuels need to see we have leverage over methane that we don’t have over CO2.  We must use it.                        

            To bend the arc by 2030 we must  prevent year on year increases of  methane emissions starting 2019.  What  that would require is unclear.   I can find no global methane emission figures (which are famously imprecise anyway)  for after  2012.  Graph 2 shows that yearly emissions recorded were flat 1990 to 2002, then  rose steadily to 2012  except in 2008.  The average annual increasein those ten years  was 5.8 Mmt (million metric tons)  about 2% per year.  [Emissions of methane are typically recorded in teragrams (Tg) where 1 Tg = 1 Mmt.  For familiarity,  Mmt will be used for methane instead of Tg.]

 graph2

 Graph 2.  Global human-influenced methane emissions by year 1990-2012   in Tg (million metric tons) Data source  EDGAR       graph by Shafer

            Atmospheric concentrations of methane are more precise and timely than emissions data, though it is hard to relate the two quantitatively.  From 2006 to 2018 the concentration rose steadily from 1774 parts per billion (ppb)  to 1857 ppb, an average annual increase of about 6 ppb ( +  0.5% of 2006 baseline)  (Graph 3, below)

CH4oncbyyr

     Graph 3.    Globally averaged marine surface monthly mean CH4 concentration  1983-2019 Source Ed Dlugokencky  NOAA

 

            In short, we don’t know how much annual methane emissions have been changing since 2012.  Extrapolation of  the 2003-2012 trend and the rise in atmospheric concentrations 2006-2018 indicate they must be going up.  How fast,  it  is impossible to say precisely.

            It is plausible, though  not proven,  that all recent conjectured  annual increases in global methane emissions are due to losses of methane from the natural gas supply chain,  which moves more gas each year.  In 2005 global production of natural gas was 2.8 trillion cubic meters (tcm).  By 2018 it had gone up by 1.055 tcm ( + 81 bcm/yr),  a 2.9 %  average annual increase over baseline.  (source Rystad Energy )  [Not incidentally, more than half the increase was from USA “unconventional,”  i.e. fracked. (source Rystad Energy )]  See Graph 4 below.

 globalnatgasbyyr

 Graph 4.  Increase  in global total natural gas production above  2005 baseline of 2800 billion cubic meters /yr.  Values  thru 2018 are real; after that,  projected  source Rystad Energy

            The increase in global supply chain throughput  2017-2018 was 200 bcm;  if  (say) 5% of that was lost from the chain as methane in that year,  the increased emissions would amount to  6.5 Tg or Mmt..  [Arithmetic for  that number is in appendix.]   Ecological prudence should assume that all the increase in human-influenced methane emissions is due to natural gas withdrawal and distribution; no other emitting sector (e.g. ruminants) is growing at anything like the pace of natural gas. In fact, in the UK at least  methane from ruminants is going down.   Under this assumption, flattening the curve of natural gas production over the next ten years then holding that course  would  stop  all  subsequent additions by  methane to atmospheric heating,  a sea change. Ending all fossil fuel infrastructure expansion in New York State  forwards  this strategy.  Ending that expansion includes

  • No new conventional gas wells; fracked ones are banned
  • No new gas pipelines, long or short, no extensions no spurs
  • No new or renovated gas-fired power plants
  • No new gas storage facilities
  • No new buildings hooked up to natural gas
  • No exports of liquefied natural gas for  fuel or feedstock
  • Properly identify and cap all abandoned gas wells
  • Carbon fee & dividend  on natural gas with agricultural exemption for specified covered fuels
  • Top priority for renewable energy sources like wind and solar, battery storage
  • Government and private (utility) incentives for renewable heat technologies
  • No federal subsidies for natural gas systems

            This is not a call to shut down natural gas in the USA in 2020.  It is a call to keep it from growing.  Cricket Valley Energy,  CPV Valley,  Danskammer,  the proposed National Grid E37 Albany Loop and the proposed Williams pipeline under NY Harbor (to name just five) must all be stopped in their tracks  Past that inflection point, withdrawal and consumption need to be reduced speedily in sectors (electricity generation, structure heating) that have a renewable alternative.  Reducing methane emissions year on year will start cooling  the atmosphere after ten years.  Reducing CO2 emissions  is crucial,  but by itself will never promote cooling.

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Divergent metrics for methane’s heating effect

by Stephen Shafer on October 26, 2019

CO2-e , CO2-e* and CO2-ew:  Divergent  Metrics for  Methane’s Additions  to  Atmospheric Heating in Scenarios of Sub-optimal or no Mitigation.

 playgroundfackpad

 photo of a playground in Butler Co PA USA next to a fracking pad is by Moms for Clean Air Force   source: www.climatevisuals.org

Summary: I did simulations using the GWP and the variant GWP* framework for future scenarios of  annual methane emissions that trend over 10-20  years to be level or falling.  In  these  hypothetical “ambitious mitigation”  scenarios,  emissions of the short-lived climate pollutant methane  after about ten years  don’t  add to atmospheric heating even when the  GWP approach  would say they do.   No paper I could find quantifies the difference in future additions to heating predicted by GWP* vs GWP methods when methane emissions trend up as they must be these days.  With simple algebra,  CO2-e derived from GWP was compared to CO2-e* derived from GWP* framework and to the yet-newer metric CO2-we for both slow rise and faster rise.  For  annual increases less than 1.25%/yr  over baseline,  CO2-e predicts  more addition to atmospheric  heating than does  CO2-e*.  For higher rates of annual increase, however,  CO2-e* and CO2-we both exceed CO2-e.  The “star” methodology  ( yielding CO2-e*  or CO2-we rather than CO2-e) should become the norm for methane.  It shows the benefits of ambitious and even of suboptimal mitigation.  It  highlights the dreadful  consequences of letting natural gas withdrawals continue to rise as steeply as they have been in the United States (66% increase 2006-2018).

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CO2-e is the Wrong Metric for Methane’s Heating Effects

October 10, 2019

     Schematic illustration of how global mean temperatures respond to different emissions trends in carbon dioxide (CO2) and methane (CH4)  source Allen, Cain Lynch Frame (2018)   Summary The atmosphere,  a major sector of the carbon cycle,  manages methane (CH4) and carbon dioxide (CO2)  very differently.   Use of a Global Warming Potential ratio (GWP)  [...]

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Methane Manifest

September 29, 2019

                                                                                                                                                        Methane Manifest                                                                                        Idealized conception of fracking   source http://greenplug.nu/hydraulic-fracturing-what-is-hydraulic-fracturing/  Summary By holding yearly methane emissions constant or falling for the next ten years and keeping them on that track thereafter, humanity could arrest that gas’s outsize additions to atmospheric heat-trapping.  Letting methane emissions rise year after year as they are almost certainly doing [...]

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Methane madness

August 10, 2019

  Rising unacknowledged  emissions of methane from the natural gas supply chain  are dangerously under-estimated as  a driver  of global heating and must be ended. Stephen Q. Shafer  MD MA MPH                                                                                                     Aerial view of fracking pad in Pennsylvania  photo source Smithsonian magazine Summary:  The  natural gas industry  is now  the largest source  of [...]

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Over-heaters Anonymous:the Methane Diet

June 24, 2019

                                                                                                    Why We Must Control  Methane Emissions Now! Note:  the title of this post has been changed to that immediately  above,  because the original title was a weak pun about a serious topic.  I have not changed the permalink,, since that is in  circulation already.  http://www.anchorageromneys.com/2019/06/over-heaters-a…e-methane-diet Summary:  This picture-essay   explains  why methane  must [...]

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Biologically Enhanced Agricultural Management

March 11, 2019

                                        Biologically Enhanced Agricultural Management (BEAM)                                Summary: Views of a regenerative grazier and climate hawk  on  Biologically Enhanced Agricultural Management,  a system to boost soil organic carbon and  improve soil health without chemical inputs. BEAM  uses  a  low-tech composting method  (static [...]

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Potential of Different Practices for Carbon Sequestration in Soils

February 25, 2019

                           Potential of  Different Practices for Carbon Sequestration in Soil               This essay starts with  the current loci of carbon sequestration, geological hydrological and biological.  I’ll  then review  some “natural solutions”  for near-term biological C-sequestration, which are mostly through photosynthesis in living organisms.  I will look at  the potential for various of these to contribute [...]

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Soil Your Undies

November 5, 2018

Introduction Soil your undies or soil my undies  is an international gimmick to show that soil is alive and  demonstrate  its vigor.  A pair of  brand-new 100% cotton underpants is left underground to the mercies of soil biota,  then retrieved after exactly two months for public display  Here’s one of many how-to descriptions.      Procedures vary.  [...]

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Why Agriculture Needs and Merits Financial Help from Carbon Fee Revenues

January 18, 2018

                                        photo Memories of the Dust Bowl      Pinterest  90deffe52297bcda9b2cfa8277288516   The  seventh   essay in a series on how American agriculture can  thrive in  a strenuous good-faith effort to halt global warming.  The  first six,   earliest first, are these: 1.   What-is-a-carbon-footprint  2.    [...]

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