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INVENTORY OF U.S. GREENHOUSE GAS EMISSIONS AND SINKS: 1990-2003

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  • Sonya
    INVENTORY OF U.S. GREENHOUSE GAS EMISSIONS AND SINKS: 1990-2003 FINAL VERSION (April 2005) EPA 430-R-05-003 -- Please note the 50% rise in the highest warming
    Message 1 of 2 , May 1, 2005
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      INVENTORY OF U.S. GREENHOUSE GAS EMISSIONS AND SINKS: 1990-2003
      FINAL VERSION (April 2005) EPA 430-R-05-003

      -- Please note the 50% rise in the highest warming potential greenhouse
      gases mentioned
      in the excerpts from the EPA U.S. Inventory of Greenhouse Gas Emissions
      and Sinks 2005 report
      below that I posted versus the

      ** During the same period, aggregate weighted emissions of HFCs, PFCs,
      and SF6 rose by 45.8 Tg CO2 Eq. (50 percent).
      Page ES-1 ---substances—hydrofluorocarbons (HFCs),
      perfluorocarbons (PFCs), and sulfur hexafluoride (SF6)—
      do not deplete stratospheric ozone but are
      potent greenhouse gases. Despite being emitted in smaller
      quantities relative to the other principal greenhouse gases, emissions
      of HFCs, PFCs, and SF6 are significant because many of them have
      extremely high global warming potentials and, in the cases of PFCs and
      SF6, long atmospheric lifetimes*

      Qualitatively speaking, this could be more significant than the rise over
      the years of CO2 , in relation to atmospheric lifespan, global warming
      potential,
      and the incremental portion the total percentage of the GHG amounts....

      HCFCs are compounds containing carbon, hydrogen, chlorine and fluorine.

      "Sulfur hexafluoride is the most potent greenhouse gas the IPCC
      has evaluated. "

      All of the other non-CO2 greenhouse gas are more effective at trapping
      heat than CO2.

      A rise in this emissions will result and impact
      the climatic processes more so in relation to the aspect that CO2 has a
      global
      warming potential of 1, the lowest of all the GHG, and it takes 50-200
      years for CO2 breakdown in the atmosphere.

      What would be the quantify or qualifying
      factors for these non CO2 GHG that have the highest warming potential
      greenhouse gases
      and are more effective at trapping heat than CO2, and the US levels have
      risen 50%.

      snip-----
      http://cdiac.esd.ornl.gov/trends/otheratg/otheratg.htm

      Oram et al. (1998) quantified the increasing atmospheric concentration
      of one halocarbon,
      fluoroform (CHF3 or HFC-23), from samples taken at Cape Grim, Tasmania.
      This persistent gas, a by-product of the manufacture of HCFC-22
      (CHClF2), has an atmospheric
      lifetime of 200-300 years and a GWP of about 10,000 times that of CO2
      on a unit-mass basis.
      The dataset included here provides the Oram et al. Cape Grim fluoroform
      data.

      Sturges et al. (2000) http://www.sciencemag.org/
      identified trifluoromethyl sulfur pentafluoride (SF5CF3) as a previously
      unreported gas that is long-lived (an atmospheric residence of several
      hundred to several thousand years)
      and with significant GWP (perhaps 18,000 times that of CO2 on a
      unit-mass basis). The database included
      here quantifies atmospheric concentrations of SF5CF3 and sulfur
      hexafluoride (SF6), another greenhouse
      gas, from 1965 through 1999, based on samples obtained from firn (deep
      consolidated snow) at Dome
      Concordia (eastern Antarctica).
      -----------------
      http://cdiac.esd.ornl.gov/trends/otheratg/sturges/sturges.html

      Sturges, W.T., T. J. Wallington, M. D. Hurley, K. P. Shine, K. Sihra, A.
      Engel, D. E. Oram, S. A. Penkett,
      R. Mulvaney, and C. A. M. Brenninkmeijer. 2000.
      Trifluoromethyl Sulfur Pentafluoride (SF5CF3) and Sulfur Hexafluoride
      (SF6) from Dome Concordia.
      In Trends: A Compendium of Data on Global Change. Carbon Dioxide
      Information Analysis Center,
      Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge,
      Tenn., U.S.A.

      Period of Record
      1965-1999

      Trends
      The measured concentration of SF5CF3 increased from zero in 1965-1966 to
      about 0.12 ppt in
      1999, with a current growth rate of about 0.008 ppt per year (about 6%
      per year). Given the similarity
      of the growth curves of SF5CF3 and SF6 (which increased from 0.18 ppt in
      1970 to 4.0 ppt in 1999),
      Sturges et al. (2000) speculate that the former may originate as a
      breakdown product of the latter in
      high-voltage equipment. While the current radiative forcing of SF5CF3
      may be minor, the high growth
      rate and long atmospheric residence time suggest that the greenhouse
      significance of this gas could
      increase markedly in the future. Conversely, SF5CF3 appears not to have
      any natural sources, so
      control might be feasible, once the sources are identified.
      --------
      Have a look at the South Pole's SF6 Mixing Ratio for today, it isn't
      good. THE SOUTH POLE.
      http://www.cmdl.noaa.gov/hats/insitu/cats/conc/sposf6.html

      I can't say that Am Samoa is any better either
      http://www.cmdl.noaa.gov/hats/insitu/cats/conc/smosf6.html

      Nor Hawaii http://www.cmdl.noaa.gov/hats/insitu/cats/conc/mlosf6.html

      Alaska was about the same as Hawaii but more proportional
      and Colorado was the lowest but still a hitting a 6
      http://www.cmdl.noaa.gov/hats/insitu/cats/conc/nwrsf6.html

      That is rather frowning when a chemical has a concerning potential of
      the highest rated GWP GHG at SF6 --- 23,900

      Based on the qualifing factor of the GWP of CO2's 1 to a 16% of the
      other non CO2s, with 2% of those
      being the very high level GWPs, and the other GHGs all being higher
      rated GWP than CO2,
      and discounting water vapor-----especially when we have a 3 to 10 rise
      in HFC23 a synthetic man made chemical
      and the production does not seem to be slowing down nor the levels in
      the atmosphere.......

      Further qualifying====......CO2 sustains the biosphere, the atmosphere,
      life, the very carbon cycle.........

      We most certainly do not need HFC23 for life to exist.

      Oram, D.E., W.T. Sturges, S.A. Penkett, A. McCulloch, and P.J. Fraser.
      2000.
      Atmospheric Fluoroform (CHF3, HFC-23) at Cape Grim, Tasmania. In Trends:
      A Compendium of Data on Global Change. Carbon Dioxide Information
      Analysis Center,
      Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge,
      Tenn., U.S.A.

      http://cdiac.esd.ornl.gov/ftp/trends/otheratg/oram/oramdata.txt
      Date CHF3 concentration
      1978 3.13
      1995 11.08

      http://cdiac.esd.ornl.gov/trends/otheratg/oram/oram.html

      Trends
      The measured concentration of fluoroform at Cape Grim has increased from
      about 2 pptv in early
      1978 to about 11 pptv by late 1995. The current growth rate is 0.55 pptv
      per year over the period 1990-1995,
      or about 5% per year relative to the late 1995 value.

      References

      Oram, D.E., W.T. Sturges, S.A. Penkett, A. McCulloch, and P.J. Fraser. 1998
      Growth of fluoroform (CHF3, HFC-23) in the background atmosphere.
      Geophysical Research Letters 25:35-38.

      The global estimate I could locate right now is the link below that
      shows at least 16%, cumulatively
      for the high GWP GHG.......the human made gases that it refers to are
      the so HFCs, PFCs, and SF6

      Many gases exhibit these “greenhouse” properties.
      Some of them occur in nature (water vapor, carbon dioxide, methane, and
      nitrous oxide),
      while others are exclusively human-made (like gases used for aerosols).

      http://www.eia.doe.gov/environment.html


      snip--

      Another greenhouse gas, methane; it represents 9 percent of total emissions.
      Nitrous oxide (5 percent of total emissions), meanwhile, is emitted
      from burning fossil fuels
      and through the use of certain fertilizers and industrial processes.
      Human-made gases (2 percent of total emissions)
      are released as byproducts of industrial processes and through leakage.


      The other gases and their GWP are below........

      Global Warming Potentials
      (CO2) 1
      Methane (CH4) 21
      Nitrous Oxide (N2O) 310
      HFC-23 11,700
      HFC-125 2,800
      HFC-134 1,300
      HFC-143 3,800
      HFC-152 140
      HFC-227 2,900
      HFC-236 6,300
      HFC-4310 1,300
      CF4 6,500
      C2F6 9,200
      C4F10 7,000
      C6F14 7,400
      SF6 23,900
      Source: IPCC, 1996

      http://afeas.org/2002/production_2002.html *Annual Global Fluorocarbon
      Production (metric tons)*

      0.1thousand metric tonnes were released in 1990 and over the years the
      numbers grew to 520 thousand metric tonnes in 2002.......
      Rising every year for HFC134---that would be the US....... and that
      would be the reporting companies.
      http://afeas.org/2002/emissions/hfc134a_emissions_2002.html

      More of the same throught the page......almost nil in the emissions
      department in 1990, then huge numbers by the time
      we reach 2002.
      http://afeas.org/2002/emissions/hcfc142b_emissions_2002.html
      http://afeas.org/2002/emissions/hcfc141b_emissions_2002.html

      This is of concern if you take note that the
      manufacturing processing of HCFC-22 releases the byproducts CHF3 or
      HFC-23---and
      this compound has a lifetime of 200-300 years---and GWP value of 10,000
      that of CO2's.

      http://afeas.org/2002/emissions/hcfc22_emissions_2002.html
      McCulloch A., P.M. Midgley and P. Ashford, Releases of Refrigerant Gases
      (CFC-12, HCFC-22 and HFC-134a)
      to the Atmosphere, Atmos. Environ., 37, 889-902, 2003)

      For a total page type of chart one can go here
      http://afeas.org/2002/production_2002.html *
      Annual Global Fluorocarbon Production (metric tons)

      It is a GLOBAL chart arranged by the chemical compound, the year, and
      the amount produced for that year, then
      I believe it went back to the early 1900s......
      *

      Note that some of our CO2 emissions were offset, but this is not an
      option available to us
      in relation HFCs, PFCs, and SF6 the justification of their use has been
      quantified
      in the past against the ozone layer even though other sources will still
      produce
      and emit HFCs, PFCs, and SF6........so the logic used below paragraph is
      escaping me

      "Emissions from substitutes for ozone depleting substances are both the
      largest and the fastest growing source of HFC, PFC and SF6 emissions..
      The increase in ODS emissions is offset substantially by decreases in
      emission of HFCs, PFCs, and SF6 from other sources. "

      Okay----save the ozone layer--which does not seem to be working out the way
      it was planned......and---what--, granted, I am tired,
      and maybe this is over my head but are they saying in this paragraph
      that we want to use these chemicals but we are going to make
      other companies (sources) decrease their use of xyz that breaks down
      into these chemical
      compounds so everything is hunky dory......ha ha.........

      Figure ES-4: 2003 Greenhouse Gas Emissions by Gas Overall,
      from 1990 to 2003, total emissions of CO2 increased by 832.0 Tg CO2 Eq.
      (17 percent), while CH4 and N2O emissions decreased by 60.4 Tg CO2 Eq.
      (10 percent) and 5.2 Tg CO2 Eq. (1 percent), respectively.

      During the same period, aggregate weighted emissions of HFCs, PFCs,
      and SF6 rose by 45.8 Tg CO2 Eq. (50 percent). The length of time
      Length of time 11,700 years (HFC-23) will last in the atmosphere and
      this chemical
      compound increased *3 to 10 parts per trillion (ppt) and the levels
      continue to rise.
      *
      Despite being emitted in smaller
      quantities relative to the other principal greenhouse gases, emissions
      of HFCs, PFCs, and SF6 are significant because many of them have
      extremely high global warming potentials and, in the cases of PFCs and
      SF6, long atmospheric lifetimes. Conversely, U.S. greenhouse gas
      emissions were partly offset by carbon sequestration in forests, trees
      in urban areas, agricultural soils, and landfilled yard trimmings and
      food scraps, which, in aggregate, offset 12 percent of total emissions
      in 2003. The following sections describe each gas’ contribution to total
      U.S. greenhouse gas emissions in more detail.

      I would guesstimate that one of the main reasons that attention is being
      focused on decreasing
      CO2 emissions COULD be because there are plants, soils, and the ocean
      that help
      mitigate and regulate the fluxes of the carbon cycle ---
      sinks---whereas, with the synthetic man made
      GHG gases-- there are not these many of these conditional factors
      that we can tangibly relate to and translate into sinks.

      And-----money can be made from trading carbon emissions.......they
      thought about that 20 years ago if one
      reads some of the very old reports, how to make it psychologically
      attractive..

      I believe there have been two CDM HFC23 decreasing projects......and
      that's all, as far
      as money making, oh, wait, and some of the nitro reducing retro
      fittings.......
      I am sure there are few others here and there, but absolutely nothing in
      comparison to carbon trading.....

      With a 50% rise versus the significantly smaller CO2 rise, and with a much
      higher global warming potential and ozone depletion----
      some perspective..........

      Selected HCFCs are measured as part of the
      Chlorofluorocarbon Alternatives Measurement Project
      <camp.html>http://www.cmdl.noaa.gov/hats/flask/camp.html <camp.html>
      within the Flask Sampling Program <flasks.html>
      http://www.cmdl.noaa.gov/hats/flask/flasks.html
      of the Halocarbons and other Atmospheric Trace Species Group (HATS)
      <../index.html> http://www.cmdl.noaa.gov/hats/index.html of
      NOAA/CMDL </index.html> http://www.cmdl.noaa.gov/index.html

      Data and a graph <ftp://ftp.cmdl.noaa.gov/hats/hcfcs/>
      ftp://ftp.cmdl.noaa.gov/hats/hcfcs/
      of published data and updates to the published trends are available for
      HCFC-22, HCFC-141b, and HCFC142b.

      Data and a graph
      ftp://ftp.cmdl.noaa.gov/hats/hfcs/
      of published data and updates to the published trends are available for
      HFC-134a.
      Some frequently asked questions regarding HFCs…

      snip-----

      Furthermore, along with measurements of alternatives to ozone-depleting
      substances, GC-MS analysis
      of flasks in this program has provided a wealth of unique data for other
      important trace gases on a global scale.
      ata for CFCs and other ozone-depleting substances from GC-MS analysis of
      flasks are semi-independent from
      esults obtained with electron capture instruments located in the field.
      Although flasks allow for only a much lower
      sampling frequency than on-site instrumentation, flask samples are
      collected at many more sites than currently
      have on-site instrumentation. As of 2001, flasks were being analyzed
      from 12 stations across the globe; HATS on
      -site instruments are collecting data at 5 remote sites for the major
      ozone depleting gases, HCFC-22, the methyl
      halides, N2O, and SF6.


      Can the true mechanism be assayed and sorted out....the, who, whats, wheres
      and whys....of a triggering factor for unusual climate changes.....

      Or could the trigger factor be
      computed for which percentage, of the who, what, and where would trigger
      which xyz part of the climate process
      or the presence of one these mechanisms would reflect in positive or
      negative feedbacks, or direct or indirecting forcings......

      I'd be inclined to think not, especially, when it is the climate
      processes and biosphere is very non linear, chaotic, and the interacting
      processes and exchanges are so depending upon each other, for example,
      the sun keeps the planets in reign with it's magnetic field.....
      even the sun controls the planets......their is a natural process and
      exchange not dependent on any feedback or forcing, it is just part of the
      mechanisms of things.......such as how the atmospheric gases, the GHGs
      ones included, interact with the ocean, the soil, the plants,
      and so forth. CO2 is needed to sustain life on the earth.

      Without CO2, life, as we know it would not have developed.......
      What do we do if there is not enough CO2.......when the fossil fuels are
      gone
      and the emissions are not there.........lol......... :)

      And what about Methane Emissions

      " According to the
      IPCC, CH4 is more than 20 times as effective as CO2 at trapping heat in
      the atmosphere. Over the last two hundred and fifty years, the
      concentration of CH4 in the atmosphere increased by 150 percent (IPCC
      2001). "

      And Nitrous Oxide

      "While total N2O emissions are
      much lower than CO2 emissions, N2O is approximately 300 times more
      powerful than CO2 at trapping heat in the atmosphere. Since 1750, the
      atmospheric concentration of N2O has risen by approximately 16 percent
      (IPCC 2001)."

      No planes, trains, and automobiles lines allowed.......that doesn't
      fly.....

      Whoever would trying to go there with that line of thought, .that
      doesn't fly,
      agriculture, by far, is the largest source, hand's down..

      "Sources of N2O Some significant trends in U.S. emissions of N2O included
      the following:. Agricultural soil management activities such as
      fertilizer application and other cropping practices were the largest
      source of U.S. N2O emissions, accounting for 67 percent (253.5 Tg CO2
      Eq.).. In 2003, N2O emissions from mobile combustion were 42.1 Tg CO2
      Eq. (approximately 11 percent of U.S. N2O emissions). From 1990 to 2003,
      N2O emissions from mobile combustion decreased by 4 percent."

      Well so much for the GHG tradeoff offsetting accounting methodology
      that I posted previously of Mr. Hansen's. I can't say that I am
      surprised although,
      I was aware that Europe's level of these other GHGs was fairly high,
      especially
      Germany...... but, some, of this been speculated in relation
      to the high potential for GHG warming of the synthetic chemicals and
      fretted about.......

      High GWP Gases and Climate Change http://www.epa.gov/highgwp/scientific.html
      There are three major groups or types of high GWP gases:
      hydrofluorocarbons (HFCs),
      perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). These compounds
      are the most
      potent greenhouse gases. In addition to having high global warming
      potentials,
      SF6 and PFCs have extremely long atmospheric lifetimes, resulting in
      their essentially
      irreversible accumulation in the atmosphere once emitted (see below).

      (See the table titled Global Warming Potentials and Atmospheric
      Lifetimes <http://www.epa.gov/nonco2/econ-inv/table.html>
      http://www.epa.gov/nonco2/econ-inv/table.html
      or a listing of GWPs and atmospheric lifetimes of methane
      and the other major species of greenhouse gases for comparison.)

      Length of time 11,700 (HFC-23) will last in the atmosphere
      And notice how much that specific chemical compound has increased

      "*Between 1978 and 1995, HFC-23 concentrations have increased from
      3 to 10 parts per trillion (ppt), and continue to rise."

      **HFC-23 from HCFC-22 Production.* The only significant emissions of
      HFCs before 1990 resulted
      from generation of HFC-23 as a byproduct of the production of HCFC-22.
      HCFC-22 is currently used in refrigeration and air-conditioning systems
      and as a
      chemical feedstock for manufacturing synthetic polymers.
      http://www.epa.gov/highgwp/sources.html
      *
      *Hydrofluorocarbons (HFCs)
      *http://www.epa.gov/highgwp/scientific.html#hfc

      *
      Hydrofluorocarbons (HFCs)
      HFCs are man-made chemicals, many of which have been developed as
      alternatives to
      ozone-depleting substances (ODS) for industrial, commercial, and
      consumer products.
      The global warming potentials of HFCs range from 140 (HFC-152a) to
      11,700 (HFC-23).
      The atmospheric lifetime for HFCs varies from just over a year for
      HFC-152a to 260 years
      or HFC-23. Most of the commercially used HFCs have atmospheric lifetimes
      less than 15 years;
      e.g., HFC-134a, which i sused in automobile air conditioning and
      refrigeration, has an atmospheric life of 14 years.

      The HFCs with the largest measured atmospheric abundances are (in
      order), HFC-23 (CHF3),
      HFC-134a (CF3CH2F), and HFC-152a (CH3CHF2). The only significant
      emissions of HFCs before
      1990 were of the chemical HFC-23, which is generated as a byproduct of
      the production of HCFC-22.
      HFCs are primarily used as a substitute for ozone-depleting chemicals.
      Between 1978 and 1995, HFC-23
      concentrations have increased from 3 to 10 parts per trillion (ppt), and
      continue to rise. Since 1990,
      when it was almost undetectable, global average concentrations of
      HFC-134a have risen significantly to
      almost 10 ppt (parts per trillion). HFC-134a has an atmospheric
      lifetime of about 14 years and its abundance
      is expected to continue to rise in line with its increasing use as a
      refrigerant around the world. HFC-152a has
      increased steadily to about 0.3 ppt in 2000, however its relatively
      short life time (1.4 years) has kept its atmospheric
      concentration below 1 ppt


      Perfluorocarbons (PFCs)


      http://www.epa.gov/highgwp/scientific.html#pfc


      Primary aluminum production and semiconductor manufacture are the
      largest known man-made
      sources of two perfluorocarbons – CF_4 (tetrafluoromethane) and C_2 F_6
      (hexafluoroethane).
      The GWP of CF_4 and C_2 F_6 emissions is equivalent to approximately
      6,500 and 9,200 tonnes,
      respectively. PFCs are also relatively minor substitutes for
      ozone-depleting substances (ODSs).

      PFCs have extremely stable molecular structures and are largely immune
      to the chemical processes
      in the lower atmosphere that break down most atmospheric pollutants. Not
      until the PFCs reach the
      mesosphere, about 60 kilometers above Earth, do very high-energy
      ultraviolet rays from the sun destroy them
      . This removal mechanism is extremely slow and as a result PFCs
      accumulate in the atmosphere and remain
      there for several thousand years. The estimated atmospheric lifetimes
      for CF_4 and C_2 F_6 are 50,000 and
      10,000 years respectively. Measurements in 2000 estimate CF_4 global
      concentrations in the stratosphere
      at over 70 parts per trillion (ppt). Recent relative rates of increase
      in concentrations for two of the most
      important PFCs are 1.3% per year for CF_4 and 3.2% per year for C_2 F_6



      Sulfur Hexafluoride (SF_6 )


      http://www.epa.gov/highgwp/scientific.html#sf6

      The global warming potential of SF_6 is 23,900, making it the most
      potent greenhouse gas the IPCC has evaluated.
      SF_6 is a colorless, odorless, nontoxic, nonflammable gas with
      excellent dielectric properties. SF_6 is used for
      insulation and current interruption in electric power transmission and
      distribution equipment, in the magnesium
      industry to protext molten magnesium from oxidation and potentially
      violent burning, in semiconductor manufacturing
      to create circuitry patterns on silicon wafers, and as a tracer gas for
      leak detection.

      Like the other high GWP gases, there are very few sinks for SF_6 , so
      all man-made sources
      contribute directly to its accumulation in the atmosphere. Measurements
      of SF_6 show that its
      global average concentration has increased by about 7% per year during
      the 1980s and 1990s,
      from less 1 ppt in 1980 to almost 4 ppt in the late 1990’s (IPCC, 2001).
      -------------------

      Snip---------

      There are three major groups or types of high GWP gases:
      hydrofluorocarbons (HFCs),
      perfluorocarbons (PFCs), and sulfur hexafluoride (SF_6 ). These
      compounds are the most potent greenhouse gases.
      In addition to having high global warming potentials, SF_6 and PFCs have
      extremely long atmospheric lifetimes,
      resulting in their essentially irreversible accumulation in the
      atmosphere once emitted (see below).


      During the same period, aggregate weighted emissions of HFCs, PFCs,
      and SF6 rose by 45.8 Tg CO2 Eq. (50 percent).

      INVENTORY OF U.S. GREENHOUSE GAS EMISSIONS AND SINKS: 1990-2003
      FINAL VERSION (April 2005) EPA 430-R-05-003

      In Brief–The U.S. Greenhouse Gas Emissions Inventory (PDF, 8 pp., 1.2 MB)
      http://yosemite.epa.gov/oar/globalwarming.nsf/UniqueKeyLookup/RAMR5CZKVE/$File/ghgbrochure.pdf

      This brochure provides an overview of the U.S. Greenhouse Gas Emissions
      Inventory
      Individual greenhouse gases and the emissions sectors are described In
      Brief.
      The Fast Facts card provides a summary of data from the most recent
      "Inventory of U.S. Greenhouse Gas Emissions and Sinks".
      Frequently used reference tables and conversions are also provided in
      this handy brochure.


      In addition to the sections below,
      http://yosemite.epa.gov/oar/globalwarming.nsf/content/ResourceCenterPublicationsGHGEmissionsUSEmissionsInventory2005.html
      the complete report (PDF, 432 pp., 6.2 MB)
      http://yosemite.epa.gov/oar/globalwarming.nsf/UniqueKeyLookup/RAMR69V4ZS/$File/05_complete_report.pdf
      is available in Acrobat (pdf) format.

      The individual files for the 2005 report are also in the pdf format. For
      spreadsheets, if you like those,
      you can download, in a zip format, the 2004 tables of the GHG
      emissions inventory from
      http://yosemite.epa.gov/oar/globalwarming.nsf/UniqueKeyLookup/RAMR5Z3RNR/$File/2004-tables.zip
      http://yosemite.epa.gov/oar/globalwarming.nsf/UniqueKeyLookup/RAMR5Z3RRD/$File/2004-tables-from-annexes.zip
      The individual tables from this document (main chapters - 142 kb WinZip
      file - and annexes - 200 kb WinZip file)
      are now available in .txt format for spreadsheet analysis. --Sonya


      The material, to download, is 432 or so pages..... I excerpted most of
      the excutive summary below......
      Comments are due within 30 days, however they do accept comments for
      publications after the 30 day
      period and you can also order a hardcopy as well.

      HOW TO OBTAIN COPIES
      You can electronically download this document on the U.S. EPA's homepage at
      <http://www.epa.gov/globalwarming/publications/emissions>.


      To request free copies of this report, call the
      National Service Center for Environmental Publications (NSCEP) at (800)
      490-9198,
      or visit the web site above and click on “order online” after selecting
      an edition.

      All data tables of this document are available for the full time series
      1990 through 2003, inclusive,
      at the internet site mentioned above.

      FOR FURTHER INFORMATION
      Contact Mr. Leif Hockstad, Environmental Protection Agency, (202)
      343-9432, hockstad.leif@....
      Or Ms. Lisa Hanle, Environmental Protection Agency, (202) 343-9434,
      hanle.lisa@....
      For more information regarding climate change and greenhouse gas
      emissions, see the EPA web site at <http://www.epa.gov/globalwarming>.

      Released for printing: April 15, 2005
      [INSERT DISCUSSION OF COVER DESIGN] Preface
      The United States Environmental Protection Agency (EPA) prepares the
      official U.S. Inventory of Greenhouse Gas
      Emissions and Sinks to comply with existing commitments under the
      United Nations Framework Convention
      on Climate Change (UNFCCC).1 Under decision 3/CP.5 of the UNFCCC
      Conference of the Parties, national
      inventories for UNFCCC Annex I parties should be provided to the UNFCCC
      Secretariat each year by April 15.
      In an effort to engage the public and researchers across the country,
      the EPA has instituted an annual public
      review and comment process for this document. The availability of the
      draft document is announced via
      Federal Register Notice and is posted on the EPA web site.
      2 Copies are also mailed upon request.

      The public comment period is generally limited to 30 days;
      however, comments received after the closure of the public comment
      period are
      accepted and considered for the next edition of this annual report.

      See Article 4(1)(a) of the United Nations Framework Convention on
      Climate Change <http://www.unfccc.int>.
      See <http://www.epa.gov/globalwarming/publications/emissions>.
      1 See Article 4(1)(a) of the United Nations Framework Convention on
      Climate Change <http://www.unfccc.int>.

      Executive Summary

      Central to any study of climate change is the
      development of an emissions inventory that identifies and quantifies a
      country's primary anthropogenic1 sources and sinks of greenhouse gases.
      This inventory adheres to both

      1) a comprehensive and detailed
      methodology for estimating sources and sinks of anthropogenic greenhouse
      gases, and 2) a common and consistent mechanism that enables Parties to
      the United Nations Framework Convention on Climate Change (UNFCCC) to
      compare the relative contribution of different emission sources and
      greenhouse gases to climate change. In 1992, the United States signed
      and ratified the UNFCCC. As stated in Article 2 of the UNFCCC, “The
      ultimate objective of this Convention…is to achieve…stabilization of
      greenhouse gas concentrations in the atmosphere at a level that would
      prevent dangerous anthropogenic interference with the climate system.
      Such a level should be achieved within a time-frame sufficient to allow
      ecosystems to adapt naturally to climate change, to ensure that food
      production is not threatened and to enable economic development to
      proceed in a sustainable manner

      .”2 Parties to the Convention, by
      ratifying, “shall develop, periodically update, publish and make
      available…national inventories of anthropogenic emissions by sources and
      removals by sinks of all greenhouse gases not controlled by the Montreal
      Protocol, using comparable methodologies…

      ”3 The United States views this
      report as an opportunity to fulfill these commitments. This chapter
      summarizes the latest information on U.S. anthropogenic greenhouse gas
      emission trends from 1990 through 2003. To ensure that the U.S.
      emissions inventory is comparable to those of other UNFCCC Parties, the
      estimates presented here were calculated using methodologies consistent
      with those recommended in the Revised 1996 IPCC Guidelines for National
      Greenhouse Gas Inventories (IPCC/UNEP/OECD/IEA 1997), the IPCC Good
      Practice Guidance and Uncertainty Management in National Greenhouse Gas
      Inventories (IPCC 2000), and the IPCC Good Practice Guidance for Land
      Use, Land Use Change and Forestry (IPCC 2003). The structure of this
      report is consistent with the UNFCCC guidelines for inventory
      reporting.4 For most source categories, the IPCC methodologies were
      expanded, resulting in a more comprehensive and detailed estimate of
      emissions.

      ES.1. Background Information Naturally occurring greenhouse
      gases include water vapor, carbon dioxide (CO2), methane (CH4), nitrous
      oxide (N2O), and ozone (O3). Several classes of halogenated substances
      that contain fluorine, chlorine, or bromine are also greenhouse gases,
      but they are, for the most part, solely a product of industrial
      activities. Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons
      (HCFCs) are halocarbons that contain chlorine, while halocarbons that
      contain bromine are referred to as bromofluorocarbons (i.e., halons). As
      stratospheric ozone depleting substances, CFCs, HCFCs, and halons are
      covered under the Montreal Protocol on Substances that Deplete the Ozone
      Layer. The UNFCCC defers to this earlier international treaty.
      Consequently, Parties are not required to include these gases in their
      national greenhouse gas emission inventories.5 Some other fluorine-
      containing halogenated 1 The term “anthropogenic”, in this context,
      refers to greenhouse gas emissions and removals that are a direct result
      of human activities or are the result of natural processes that have
      been affected by human activities (IPCC/UNEP/OECD/IEA 1997). 2 Article 2
      of the Framework Convention on Climate Change published by the UNEP/WMO
      Information Unit on Climate Change. See <http://unfccc.int>. 3 Article
      4(1)(a) of the United Nations Framework Convention on Climate Change
      (also identified in Article 12). Subsequent decisions by the Conference
      of the Parties elaborated the role of Annex I Parties in preparing
      national inventories. See <http://unfccc.int>. 4 See
      <http://unfccc.int/resource/docs/cop8/08.pdf>.

      5 Emissions estimates of
      CFCs, HCFCs, halons and other ozone-depleting substances are included in
      this document for informational purposes. Page ES-1 ---
      substances—hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and
      sulfur hexafluoride (SF6)—do not deplete stratospheric ozone but are
      potent greenhouse gases. These latter substances are addressed by the
      UNFCCC and accounted for in national greenhouse gas emission
      inventories. There are also several gases that do not have a direct
      global warming effect but indirectly affect terrestrial and/or solar
      radiation absorption by influencing the formation or destruction of
      other greenhouse gases, including tropospheric and stratospheric ozone.
      These gases include carbon monoxide (CO), oxides of nitrogen (NOx), and
      non-methane volatile organic compounds (NMVOCs).

      Aerosols, which are
      extremely small particles or liquid droplets, such as those produced by
      sulfur dioxide (SO2) or elemental carbon emissions, can also affect the
      absorptive characteristics of the atmosphere. Although the direct
      greenhouse gases CO2, CH4, and N2O occur naturally in the atmosphere,
      human activities have changed their atmospheric concentrations. Since
      the pre-industrial era (i.e., ending about 1750), concentrations of
      these greenhouse gases have increased by 31, 150, and 16 percent,
      respectively (IPCC 2001). Beginning in the 1950s, the use of CFCs and
      other stratospheric ozone depleting substances (ODSs) increased by
      nearly 10 percent per year until the mid-1980s, when international
      concern about ozone depletion led to the entry into force of the
      Montreal Protocol. Since then, the production of ODSs is being phased
      out. In recent years, use of ODS substitutes such as HFCs and PFCs has
      grown as they begin to be phased in as replacements for CFCs and HCFCs.
      Accordingly, atmospheric concentrations of these substitutes have been
      growing (IPCC 2001). Global Warming Potentials Gases in the atmosphere
      can contribute to the greenhouse effect both directly and indirectly.
      Direct effects occur when the gas itself absorbs radiation.

      Indirect
      radiative forcing occurs when chemical transformations of the substance
      produce other greenhouse gases, when a gas influences the atmospheric
      lifetimes of other gases, and/or when a gas affects atmospheric
      processes that alter the radiative balance of the earth (e.g., affect
      cloud formation or albedo).6 The IPCC developed the Global Warming
      Potential (GWP) concept to compare the ability of each greenhouse gas to
      trap heat in the atmosphere relative to another gas. The GWP of a
      greenhouse gas is defined as the ratio of the time-integrated radiative
      forcing from the instantaneous release of 1 kg of a trace substance
      relative to that of 1 kg of a reference gas (IPCC 2001).

      Direct
      radiative effects occur when the gas itself is a greenhouse gas. The
      reference gas used is CO2, and therefore GWP-weighted emissions are
      measured in teragrams of CO2 equivalent (Tg CO2 Eq.).7 All gases in this
      Executive Summary are presented in units of Tg CO2 Eq. The relationship
      between gigagrams (Gg) of a gas and Tg CO2 Eq. can be expressed as
      follows: ( ) ( ) ...
      .. ..
      . × × = Gg 1,000 Tg GWP gas of Gg Eq CO Tg 2 The UNFCCC reporting
      guidelines for national inventories were updated in 2002,8 but continue
      to require the use of GWPs from the IPCC Second Assessment Report (SAR).
      This requirement ensures that current estimates of aggregate greenhouse
      gas emissions for 1990 to 2003 are consistent with estimates developed
      prior to the publication of the IPCC Third Assessment Report (TAR).
      Therefore, to comply with international reporting standards under the
      UNFCCC, official emission estimates are reported by the United States
      using SAR GWP values. All estimates are provided throughout the report
      in both CO2 equivalents and unweighted units. A 6 Albedo is a measure of
      the Earth’s reflectivity; see the Glossary (Annex 6.8) for definition. 7
      Carbon comprises 12/44ths of carbon dioxide by weight. 8 See
      <http://unfccc.int/resource/docs/cop8/08.pdf>. Page ES-2

      comparison of emission values using the SAR GWPs versus the TAR GWPs
      can be found in Chapter 1 and in more detail in Annex 6.1.

      The GWP
      values used in this report are listed below in Table ES-1. Table ES-1:
      Global Warming Potentials (100 Year Time Horizon) Used in this Report
      Gas GWP CO2 1 CH4 * 21 N2O 310 HFC-23 11,700 HFC-32 650 HFC-125 2,800
      HFC-134a 1,300 HFC-143a 3,800 HFC-152a 140 HFC-227ea 2,900 HFC-236fa
      6,300 HFC-4310mee 1,300 CF4 6,500 C2F6 9,200 C4F10 7,000 C6F14 7,400 SF6
      23,900 Source: IPCC (1996) * The methane GWP includes the direct effects
      and those indirect effects due to the production of tropospheric ozone
      and stratospheric water vapor. The indirect effect due to the production
      of CO2 is not included. Global warming potentials are not provided for
      CO, NOx, NMVOCs, SO2, and aerosols because there is no agreedupon method
      to estimate the contribution of gases that are short-lived in the
      atmosphere, spatially variable, or have only indirect effects on
      radiative forcing (IPCC 1996). ES.2.

      Recent Trends in U.S. Greenhouse
      Gas Emissions and Sinks In 2003, total U.S. greenhouse gas emissions
      were 6,900.2 Tg CO2 Eq. Overall, total U.S. emissions have risen by 13
      percent from 1990 to 2003, while the U.S. gross domestic product has
      increased by 46 percent over the same period (BEA 2004). Emissions rose
      slightly from 2002 to 2003, increasing by 0.6 percent (42.2 Tg CO2 Eq.).
      The following factors were primary contributors to this increase: 1)
      moderate economic growth in 2003, leading to increased demand for
      electricity and fossil fuels, 2) increased natural gas prices, causing
      some electric power producers to switch to burning coal, and 3) a colder
      winter, which caused an increase in the use of heating fuels, primarily
      in the residential end-use sector. Figure ES-1 through Figure ES-3
      illustrate the overall trends in total U.S. emissions by gas, annual
      changes, and absolute change since 1990. Table ES-2 provides a detailed
      summary of U.S. greenhouse gas emissions and sinks for 1990 through
      2003. Figure ES-1: U.S. Greenhouse Gas Emissions by Gas Figure ES-2:
      Annual Percent Change in U.S. Greenhouse Gas Emissions Figure ES-3:
      Cumulative Change in U.S. Greenhouse Gas Emissions Relative to 1990



      Figure ES-4 illustrates the relative contribution of the direct
      greenhouse gases to total U.S. emissions in 2003. The primary greenhouse
      gas emitted by human activities in the United States was CO2,
      representing approximately 85 percent of total greenhouse gas emissions.
      The largest source of CO2, and of overall greenhouse gas emissions, was
      fossil fuel combustion. Methane emissions, which have steadily declined
      since 1990, resulted primarily from decomposition of wastes in
      landfills, natural gas systems, and enteric fermentation associated with
      domestic livestock. Agricultural soil management and mobile source
      fossil fuel combustion were the major sources of N2O emissions. The
      emissions of substitutes for ozone depleting substances and emissions of
      HFC-23 during the production of HCFC-22 were the primary contributors to
      aggregate HFC emissions. Electrical transmission and distribution
      systems accounted for most SF6 emissions, while PFC emissions resulted
      from semiconductor manufacturing and as a by-product of primary aluminum
      production.

      Figure ES-4: 2003 Greenhouse Gas Emissions by Gas Overall,
      from 1990 to 2003, total emissions of CO2 increased by 832.0 Tg CO2 Eq.
      (17 percent), while CH4 and N2O emissions decreased by 60.4 Tg CO2 Eq.
      (10 percent) and 5.2 Tg CO2 Eq. (1 percent), respectively. During the
      same period, aggregate weighted emissions of HFCs, PFCs, and SF6 rose by
      45.8 Tg CO2 Eq. (50 percent). Despite being emitted in smaller
      quantities relative to the other principal greenhouse gases, emissions
      of HFCs, PFCs, and SF6 are significant because many of them have
      extremely high global warming potentials and, in the cases of PFCs and
      SF6, long atmospheric lifetimes. Conversely, U.S. greenhouse gas
      emissions were partly offset by carbon sequestration in forests, trees
      in urban areas, agricultural soils, and landfilled yard trimmings and
      food scraps, which, in aggregate, offset 12 percent of total emissions
      in 2003. The following sections describe each gas’ contribution to total
      U.S. greenhouse gas emissions in more detail.

      Carbon Dioxide Emissions
      The global carbon cycle is made up of large carbon flows and reservoirs.
      Billions of tons of carbon in the form of CO2 are absorbed by oceans and
      living biomass (i.e., sinks) and are emitted to the atmosphere annually
      through natural processes (i.e., sources). When in equilibrium, carbon
      fluxes among these various reservoirs are roughly balanced. Since the
      Industrial Revolution, atmospheric concentrations of CO2 have risen
      about 31 percent (IPCC 2001), principally due to the combustion of
      fossil fuels. Within the United States, fuel combustion accounted for 95
      percent of CO2 emissions in 2003. Globally, approximately 24,240 Tg of
      CO2 were added to the atmosphere through the combustion of fossil fuels
      in 2000, of which the United States accounted for about 23 percent.

      Changes in land use and forestry practices can also emit CO2 (e.g.,
      through conversion of forest land to agricultural or urban use) or can
      act as a sink for CO2 (e.g., through net additions to forest biomass).
      Figure ES-5: 2003 Sources of CO2 As the largest source of U.S.
      greenhouse gas emissions, CO2 from fossil fuel combustion has accounted
      for a nearly constant 80 percent of GWP weighted emissions since 1990.
      Emissions of CO2 from fossil fuel combustion increased at an average
      annual rate of 1.3 percent from 1990 to 2003. The fundamental factors
      influencing this trend include (1) a generally growing domestic economy
      over the last 13 years, and (2) significant growth in emissions from
      transportation activities and electricity generation.

      Between 1990 and
      2003, CO2 emissions from fossil fuel combustion increased from 4,711.7
      Tg CO2 Eq. to 5,551.6 Tg CO2 Eq..an 18 percent total increase over the
      thirteen-year period. Historically, changes in emissions from fossil
      fuel combustion have been the dominant factor affecting U.S. emission
      trends. From 2002 to 2003, these emissions increased by 50.2 Tg CO2 Eq.
      (1 percent). A number of factors played a major role in the magnitude of
      this increase. The U.S. economy experienced moderate growth from 2002,
      causing an increase in the demand for fuels. The price of natural gas
      escalated dramatically, causing some electric power producers to switch
      to coal, which remained at relatively stable prices. Colder winter
      conditions brought on more demand for heating fuels, primarily in the
      residential sector. Though a cooler summer partially offset demand for
      electricity as the use of air-conditioners decreased, electricity
      consumption continued to increase in 2003.

      The primary drivers behind
      this trend were the growing economy and the increase in U.S. housing
      stock. Use of nuclear and renewable fuels remained relatively stable.
      Nuclear capacity decreased slightly, for the first time since 1997. Use
      of renewable fuels rose slightly due to increases in the use of
      hydroelectric power and biofuels.

      Figure ES-6: 2003 CO2 Emissions from
      Fossil Fuel Combustion by Sector and Fuel Type Figure ES-7:

      2003 End-Use
      Sector Emissions of CO2 from Fossil Fuel Combustion The four major end-
      use sectors contributing to CO2 emissions from fossil fuel combustion
      are industrial, transportation, residential, and commercial. Electricity
      generation also emits CO2, although these emissions are produced as they
      consume fossil fuel to provide electricity to one of the four end-use
      sectors.

      For the discussion below, electricity generation emissions have
      been distributed to each end-use sector on the basis of each sector’s
      share of aggregate electricity consumption. This method of distributing
      emissions assumes that each end-use sector consumes electricity that is
      generated from the national average mix of fuels according to their
      carbon intensity. In reality, sources of electricity vary widely in
      carbon intensity. By assuming the same carbon intensity for each enduse
      sector's electricity consumption, for example, emissions attributed to
      the residential end-use sector may be underestimated, while emissions
      attributed to the industrial end-use sector may be overestimated.

      Emissions from electricity generation are also addressed separately
      after the end-use sectors have been discussed. Note that emissions from
      U.S. territories are calculated separately due to a lack of specific
      consumption data for the individual end-use sectors. Figure ES-6, Figure
      ES-7, and Table ES-3 summarize CO2 emissions from fossil fuel combustion
      by end-use sector. 9 Global CO2 emissions from fossil fuel combustion
      were taken from Marland et al. (2003)
      <http://cdiac.esd.ornl.gov/trends/emis/tre_glob.htm>.

      Transportation End-Use Sector. Transportation activities (excluding
      international bunker fuels) accounted for 32 percent of CO2 emissions
      from fossil fuel combustion in 2003.10 Virtually all of the energy
      consumed in this enduse sector came from petroleum products. Over 60
      percent of the emissions resulted from gasoline consumption for personal
      vehicle use. The remaining emissions came from other transportation
      activities, including the combustion of diesel fuel in heavy-duty
      vehicles and jet fuel in aircraft. Industrial

      End-Use Sector.
      Industrial CO2 emissions, resulting both directly from the combustion of
      fossil
      fuels and indirectly from the generation of electricity that is consumed
      by industry, accounted for 28 percent of CO2 from fossil fuel combustion
      in 2003. About half of these emissions resulted from direct fossil fuel
      combustion to produce steam and/or heat for industrial processes. The
      other half of the emissions resulted from consuming electricity for
      motors, electric furnaces, ovens, lighting, and other applications.
      Residential and Commercial End-Use Sectors. The residential and
      commercial end-use sectors accounted for 21 and 18 percent,
      respectively, of CO2 emissions from fossil fuel combustion in 2003. Both
      sectors relied heavily on electricity for meeting energy demands, with
      67 and 76 percent, respectively, of their emissions attributable to
      electricity consumption for lighting, heating, cooling, and operating
      appliances.

      The remaining emissions were due to the consumption of
      natural gas and petroleum for heating and cooking. Electricity
      Generation. The United States relies on electricity to meet a
      significant portion of its energy demands, especially for lighting,
      electric motors, heating, and air conditioning. Electricity generators
      consumed 35 percent of U.S. energy from fossil fuels and emitted 41
      percent of the CO2 from fossil fuel combustion in 2003. The type of fuel
      combusted by electricity generators has a significant effect on their
      emissions. For example, some electricity is generated with low CO2
      emitting energy technologies, particularly non-fossil options such as
      nuclear, hydroelectric, or geothermal energy. However, electricity
      generators rely on coal for over half of their total energy requirements
      and accounted for 93 percent of all coal consumed for energy in the
      United States in 2003. Consequently, changes in electricity demand have
      a significant impact on coal consumption and associated CO2 emissions.
      Other significant CO2 trends included the following:

      Carbon dioxide emissions from iron and steel production decreased to
      53.8 Tg CO2 Eq. in 2003, and have declined by 31.7 Tg CO2 Eq. (37
      percent) from 1990 through 2003, due to reduced domestic production of
      pig iron, sinter, and coal coke.. Carbon dioxide emissions from waste
      combustion (18.8 Tg CO2 Eq. in 2003) increased by 7.9 Tg CO2 Eq. (72
      percent) from 1990 through 2003, as the volume of plastics and other
      fossil carbon-containing materials in municipal solid waste grew.. Net
      CO2 sequestration from land-use change and forestry decreased by 214.0
      Tg CO2 Eq. (21 percent) from 1990 through 2003. This decline was
      primarily attributable to forest soils, a result of the slowed rate of
      forest area increases after 1997. Methane Emissions According to the
      IPCC, CH4 is more than 20 times as effective as CO2 at trapping heat in
      the atmosphere. Over the last two hundred and fifty years, the
      concentration of CH4 in the atmosphere increased by 150 percent (IPCC
      2001). Experts believe that over half of this atmospheric increase was
      due to emissions from anthropogenic sources, such as landfills, natural
      gas and petroleum systems, agricultural activities, coal mining,
      wastewater treatment, stationary and mobile combustion, and certain
      industrial processes (see Figure ES-8). Figure ES-8: 2003 U.S. Sources
      of CH4 Some significant trends in U.S. emissions of CH4 included the
      following:.

      Landfills are the largest anthropogenic source of CH4
      emissions in the United States. In 2003, landfill CH4 emissions were
      131.2 Tg CO2 Eq. (approximately 24 percent of total CH4 emissions),
      which represents a decline of 41.1 Tg CO2 Eq., or 24 percent, since
      1990.. Methane emissions from coal mining declined by 28.1 Tg CO2 Eq.

      (34 percent) from 1990 to 2003, as a result of the mining of less gassy
      coal from underground mines and the increased use of methane collected
      from degasification systems. Nitrous Oxide Emissions Nitrous oxide is
      produced by biological processes that occur in soil and water and by a
      variety of anthropogenic activities in the agricultural, energy-related,
      industrial, and waste management fields. While total N2O emissions are
      much lower than CO2 emissions, N2O is approximately 300 times more
      powerful than CO2 at trapping heat in the atmosphere. Since 1750, the
      atmospheric concentration of N2O has risen by approximately 16 percent
      (IPCC 2001).

      The main anthropogenic activities producing N2O in the
      United States are agricultural soil management, fuel combustion in motor
      vehicles, manure management, nitric acid production, human sewage, and
      stationary fuel combustion (see Figure ES-9). Figure ES-9: 2003 U.S.
      Sources of N2O Some significant trends in U.S. emissions of N2O included
      the following:. Agricultural soil management activities such as
      fertilizer application and other cropping practices were the largest
      source of U.S. N2O emissions, accounting for 67 percent (253.5 Tg CO2
      Eq.).. In 2003, N2O emissions from mobile combustion were 42.1 Tg CO2
      Eq. (approximately 11 percent of U.S. N2O emissions). From 1990 to 2003,
      N2O emissions from mobile combustion decreased by 4 percent.

      HFC, PFC, and SF6 Emissions HFCs and PFCs are families of synthetic
      chemicals that are being used as alternatives to the ODSs, which are
      being phased out under the Montreal Protocol and Clean Air Act
      Amendments of 1990. HFCs and PFCs do not deplete the stratospheric ozone
      layer, and are therefore acceptable alternatives under the Montreal
      Protocol. These compounds, however, along with SF6, are potent
      greenhouse gases. In addition to having high global warming potentials,
      SF6 and PFCs have extremely long atmospheric lifetimes, resulting in
      their essentially irreversible accumulation in the atmosphere once
      emitted. Sulfur hexafluoride is the most potent greenhouse gas the IPCC
      has evaluated. Other emissive sources of these gases include HCFC-22
      production, electrical transmission and distribution systems,
      semiconductor manufacturing, aluminum production, and magnesium
      production and processing (see Figure ES-10).

      Figure ES-10: 2003 U.S.
      Sources of HFCs, PFCs, and SF6 Some significant trends in U.S. HFC, PFC
      and SF6 emissions included the following:. Emissions resulting from the
      substitution of ozone depleting substances (e.g., CFCs) have been
      increasing from small amounts in 1990 to 99.5 Tg CO2 Eq. in 2003.
      Emissions from substitutes for ozone depleting substances are both the
      largest and the fastest growing source of HFC, PFC and SF6 emissions..
      The increase in ODS emissions is offset substantially by decreases in
      emission of HFCs, PFCs, and SF6 from other sources. Emissions from
      aluminum production decreased by 79 percent (14.5 Tg CO2 Eq.) from 1990
      to 2003, due to both industry emission reduction efforts and lower
      domestic aluminum production. Emissions from the production of HCFC-22
      decreased by 65 percent (22.6 Tg CO2 Eq.), due to a steady decline in
      the emission rate of HFC-23 (i.e., the amount of HFC-23 emitted per
      kilogram of HCFC-22 manufactured) and the use of thermal oxidation at
      some plants to reduce HFC-23 emissions.

      Emissions from electric power
      transmission and distribution systems decreased by 52 percent (15.1 Tg
      CO2 Eq.) from 1990 to 2003, primarily because of higher purchase prices
      for SF6 and efforts by industry to reduce emissions. ES.3. Overview of
      Sector Emissions and Trends In accordance with the Revised 1996 IPCC
      Guidelines for National Greenhouse Gas Inventories (IPCC/UNEP/OECD/IEA
      1997), and the 2003 UNFCCC Guidelines on Reporting and Review (UNFCCC
      2003), this Inventory of U.S. Greenhouse Gas Emissions and Sinks is
      segregated into six sector-specific chapters. Figure ES-11 and Table ES-
      4 aggregate emissions and sinks by these chapters. Figure ES-11: U.S.
      Greenhouse Gas Emissions by Chapter/IPCC Sector

      * Sinks are only included in net emissions total, and are based
      partially on projected activity data. Note: Totals may not sum due to
      independent rounding. Note: Parentheses indicate negative values (or
      sequestration).

      Energy
      The Energy chapter contains emissions of all greenhouse gases
      resulting from stationary and mobile energy activities including fuel
      combustion and fugitive fuel emissions. Energy-related activities,
      primarily fossil fuel combustion, accounted for the vast majority of
      U.S. CO2 emissions for the period of 1990 through 2003. In 2003,
      approximately 86 percent of the energy consumed in the United States was
      produced through the combustion of fossil fuels. The remaining 14
      percent came from other energy sources such as hydropower, biomass,
      nuclear, wind, and solar energy (see Figure ES-12). Energy related
      activities are also responsible for CH4 and N2O emissions (39 percent
      and 15 percent of total U.S. emissions, respectively). Overall, emission
      sources in the Energy chapter account for a combined 87 percent of total
      U.S. greenhouse gas emissions in 2003.

      Industrial Processes
      The Industrial Processes chapter contains by-
      product or fugitive emissions of greenhouse gases from industrial
      processes not directly related to energy activities such as fossil fuel
      combustion. For example, industrial processes can chemically transform
      raw materials, which often release waste gases such as CO2, CH4, and
      N2O. The processes include iron and steel production, cement
      manufacture, ammonia manufacture and urea application, lime manufacture,
      limestone and dolomite use (e.g., flux stone, flue gas desulfurization,
      and glass manufacturing), soda ash manufacture and use, titanium dioxide
      production, phosphoric acid production, ferroalloy production, CO2
      consumption, aluminum production, petrochemical production, silicon
      carbide production, nitric acid production, and adipic acid production.
      Additionally, emissions from industrial processes release HFCs, PFCs and
      SF6. Overall, emission sources in the Industrial Process chapter account
      for 4.5 percent of U.S. greenhouse gas emissions in 2003. Solvent and
      Other Product Use The Solvent and Other Product Use chapter contains
      emissions Greenhouse gas emissions are produced as a byproduct of
      various solvent and other product uses. In the United States, emissions
      from N2O Product Usage, the only source of greenhouse gas emissions from
      this sector, accounted for less than 0.1 percent of total U.S.
      anthropogenic greenhouse gas emissions on a carbon equivalent basis in
      2003.

      Agriculture
      The Agricultural chapter contains anthropogenic
      emissions from agricultural activities (except fuel combustion, which is
      addressed in the Energy chapter). Agricultural activities contribute
      directly to emissions of greenhouse gases through a variety of
      processes, including the following source categories: enteric
      fermentation in domestic livestock, livestock manure management, rice
      cultivation, agricultural soil management, and field burning of
      agricultural residues. Methane and N2O were the primary greenhouse gases
      emitted by agricultural activities. Methane emissions from enteric
      fermentation and manure management represented about 21 percent and 7
      percent of total CH4 emissions from anthropogenic activities,
      respectively in 2003. Agricultural soil management activities such as
      fertilizer application and other cropping practices were the largest
      source of U.S. N2O emissions in 2003, accounting for 67 percent. In
      2003, emission sources accounted for in the Agricultural chapters were
      responsible for 6.3 percent of total U.S. greenhouse gas emissions.

      Land-
      Use Change and Forestry The Land-Use Change and Forestry chapter
      contains emissions and removals of CO2 from forest management, other
      land-use activities, and land-use change. Forest management practices,
      tree planting in urban areas, the

      management of agricultural soils, and the landfilling of yard trimmings
      and food scraps have resulted in a net uptake (sequestration) of carbon
      in the United States. Forests (including vegetation, soils, and
      harvested wood) accounted for approximately 91 percent of total 2003
      sequestration, urban trees accounted for 7 percent, agricultural soils
      (including mineral and organic soils and the application of lime)
      accounted for 1 percent, and landfilled yard trimmings and food scraps
      accounted for 1 percent of the total sequestration in 2003. The net
      forest sequestration is a result of net forest growth and increasing
      forest area, as well as a net accumulation of carbon stocks in harvested
      wood pools.

      The net sequestration in urban forests is a result of net
      tree growth in these areas. In agricultural soils, mineral soils account
      for a net carbon sink that is approximately one and a third times larger
      than the sum of emissions from organic soils and liming. The mineral
      soil carbon sequestration is largely due to conversion of cropland to
      permanent pastures and hay production, a reduction in summer fallow
      areas in semi-arid areas, an increase in the adoption of conservation
      tillage practices, and an increase in the amounts of organic fertilizers
      (i.e., manure and sewage sludge) applied to agriculture lands. The
      landfilled yard trimmings and food scraps net sequestration is due to
      the long-term accumulation of yard trimming carbon and food scraps in
      landfills. Land use, land-use change, and forestry activities in 2003
      resulted in a net carbon sequestration of 828.0 Tg CO2 Eq. (Table ES-5).
      This represents an offset of approximately 14 percent of total U.S. CO2
      emissions, or 12 percent of total gross greenhouse gas emissions in
      2003.

      Total land use, land-use change, and forestry net carbon
      sequestration declined by approximately 21 percent between 1990 and
      2003. This decline was primarily due to a decline in the rate of net
      carbon accumulation in forest carbon stocks. Annual carbon accumulation
      in landfilled yard trimmings and food scraps also slowed over this
      period, as did annual carbon accumulation in agricultural soils. As
      described above, the constant rate of carbon accumulation in urban trees
      is a reflection of limited underlying data (i.e., this rate represents
      an average for 1990 through 1999). Land use, land-use change, and
      forestry activities in 2003 also resulted in emissions of N2O (6.4 Tg
      CO2 Eq.). Total N2O emissions from the application of fertilizers to
      forests and settlements increased by approximately 14 percent between
      1990 and 2003.

      Waste
      The Waste chapter contains emissions from waste management
      activities (except waste incineration, which is addressed in the Energy
      chapter). Landfills were the largest source of anthropogenic CH4
      emissions, accounting for 24 percent of total U.S. CH4 emissions.11
      Wastewater treatment systems are a potentially significant source of N2O
      emissions; however, methodologies are not currently available to develop
      a complete estimate. Nitrous oxide emissions from the treatment of the
      human sewage component of wastewater were estimated, however, using a 11
      Landfills also store carbon, due to incomplete degradation of organic
      materials such as wood products and yard trimmings, as described in the
      Land-Use Change and Forestry chapter.

      ES.4. Other Information Emissions by Economic Sector
      Throughout this
      report, emission estimates are grouped into six sectors (i.e., chapters)
      defined by the IPCC: Energy, Industrial Processes, Solvent Use,
      Agriculture, Land-Use Change and Forestry, and Waste. While it is
      important to use this characterization for consistency with UNFCCC
      reporting guidelines, it is also useful to allocate emissions into more
      commonly used sectoral categories. This section reports emissions by the
      following economic sectors: Residential, Commercial, Industry,
      Transportation, Electricity Generation, and Agriculture, and U.S.
      Territories. Table ES-6 summarizes emissions from each of these sectors,
      and Figure ES-13 shows the trend in emissions by sector from 1990 to
      2003. Figure ES-13: Emissions Allocated to Economic Sectors

      Note: Totals may not sum. Emissions include CO2, CH4, HFCs, PFCs, and
      SF6. See Table 2-14 for more detailed data. Using this categorization,
      emissions from electricity generation accounted for the largest portion
      (33 percent) of U.S. greenhouse gas emissions in 2003. Transportation
      activities, in aggregate, accounted for the second largest portion (27
      percent). Emissions from industry accounted for 19 percent of U.S.
      greenhouse gas emissions in 2003.

      In contrast to electricity generation
      and transportation, emissions from industry have declined over the past
      decade, as structural changes have occurred in the U.S. economy (i.e.,
      shifts from a manufacturing based to a service-based economy), fuel
      switching has occurred, and efficiency improvements have been made. The
      remaining 21 percent of U.S. greenhouse gas emissions were contributed
      by the residential, agriculture, and commercial economic sectors, plus
      emissions from U.S. Territories. Residences accounted for about 6
      percent, and primarily consisted of CO2 emissions from fossil fuel
      combustion. Activities related to agriculture accounted for roughly 7
      percent of U.S. emissions; these emissions were dominated by N2O
      emissions from agricultural soils instead of CO2 from fossil fuel
      combustion. The commercial sector accounted for about 7 percent of
      emissions, while U.S. territories accounted for 1 percent. Carbon
      dioxide was also emitted and sequestered by a variety of activities
      related to forest management practices, tree planting in urban areas,
      the management of agricultural soils, and landfilling of yard trimmings.
      Electricity is ultimately consumed in the economic sectors described
      above.

      Table ES-7 presents greenhouse gas emissions from economic
      sectors with emissions related to electricity generation distributed
      into end-use categories (i.e., emissions from electricity generation are
      allocated to the economic sectors in which the electricity is consumed).
      To distribute electricity emissions among end-use sectors, emissions
      from the source categories assigned to electricity generation were
      allocated to the residential, commercial, industry, transportation, and
      agriculture economic sectors according to retail sales of electricity.12
      These source categories include CO2 from fossil fuel combustion and the
      use of limestone and dolomite for flue gas desulfurization, CO2 and N2O
      from waste combustion, CH4 and N2O from stationary sources, and SF6 from
      electrical transmission and distribution systems. When emissions from
      electricity are distributed among these sectors, industry accounts for
      the largest share of U.S. greenhouse gas emissions (30 percent) in 2003.
      Emissions from the residential and commercial sectors also increase
      substantially due to their relatively large share of electricity
      consumption (e.g., lighting, appliances, etc.). Transportation
      activities remain the second largest contributor to emissions. In all
      sectors except agriculture, CO2 accounts for more than 75 percent of
      greenhouse gas emissions, primarily from the combustion of fossil fuels.
      Figure ES-14 shows the trend in these emissions by sector from 1990 to
      2003.

      Box ES-1: Recent Trends in Various U.S. Greenhouse Gas Emissions-
      Related Data Total emissions can be compared to other economic and
      social indices to highlight changes over time. These comparisons
      include:
      1) emissions per unit of aggregate energy consumption, because
      energy-related activities are the largest sources of emissions;
      2)emissions per unit of fossil fuel consumption, because almost all
      energy-related emissions involve the combustion of fossil fuels;
      3) emissions per unit of electricity consumption, because the electric power
      industry—utilities and nonutilities combined—was the largest source of
      U.S. greenhouse gas emissions in 2003;
      4) emissions per unit of total gross domestic product as a measure of
      national economic activity; or
      5) emissions per capita. Table ES-8 provides data on various statistics
      related to U.S. greenhouse gas emissions normalized to 1990 as a
      baseline year. Greenhouse gas emissions in the United States have grown
      at an average annual rate of 1.0 percent since 1990. This rate is slower
      than that for total energy or fossil fuel consumption and much slower
      than that for either electricity consumption or overall gross domestic
      product. Total U.S. greenhouse gas emissions have also grown more slowly
      than national population since 1990 (see Figure ES-15). Overall, global
      atmospheric CO2 concentrations.a function of many complex anthropogenic
      and natural processes.are increasing at 0.5 percent per year.

      Table ES-8: Recent Trends in Various U.S. Data (Index 1990 = 100) and
      Global Atmospheric CO2 Concentration Variable 1991
      Years 1997 1998 1999 2000 2001 2002 2003
      Growth Rate Greenhouse Gas Emissions 99 110 110 111 114 112 113 113 1.0%
      Energy Consumption 100 112 113 114 117 114 116 116 1.2%
      Fossil Fuel Consumptionb 99 112 113 114 117 115 116 116 1.2%
      Electricity Consumptionb 102 117 121 124 128 125 129 130 2.1%
      GDPc 100 122 127 133 138 139 142 146 3.0%
      Population density 101 109 110 112 113 114 115 116 1.1%
      Atmospheric CO2 Concentration 100 103 104 104 104 105 105 106 0.5% a
      GWP weighted values b
      Energy content weighted values
      (EIA 2004)
      Gross D<br/><br/>(Message over 64 KB, truncated)
    • Mike Neuman
      ... greenhouse ... Emissions ... PFCs, ... emissions ... and ... rise over ... warming ... amounts.... ... fluorine. ... trapping ... has a ... 200 ...
      Message 2 of 2 , May 2, 2005
      • 0 Attachment
        --- In Paleontology_and_Climate@yahoogroups.com, Sonya
        <msredsonya@e...> wrote:
        > INVENTORY OF U.S. GREENHOUSE GAS EMISSIONS AND SINKS: 1990-2003
        > FINAL VERSION (April 2005) EPA 430-R-05-003
        >
        > -- Please note the 50% rise in the highest warming potential
        greenhouse
        > gases mentioned
        > in the excerpts from the EPA U.S. Inventory of Greenhouse Gas
        Emissions
        > and Sinks 2005 report
        > below that I posted versus the
        >
        > ** During the same period, aggregate weighted emissions of HFCs,
        PFCs,
        > and SF6 rose by 45.8 Tg CO2 Eq. (50 percent).
        > Page ES-1 ---substancesâ€"hydrofluorocarbons (HFCs),
        > perfluorocarbons (PFCs), and sulfur hexafluoride (SF6)â€"
        > do not deplete stratospheric ozone but are
        > potent greenhouse gases. Despite being emitted in smaller
        > quantities relative to the other principal greenhouse gases,
        emissions
        > of HFCs, PFCs, and SF6 are significant because many of them have
        > extremely high global warming potentials and, in the cases of PFCs
        and
        > SF6, long atmospheric lifetimes*
        >
        > Qualitatively speaking, this could be more significant than the
        rise over
        > the years of CO2 , in relation to atmospheric lifespan, global
        warming
        > potential,
        > and the incremental portion the total percentage of the GHG
        amounts....
        >
        > HCFCs are compounds containing carbon, hydrogen, chlorine and
        fluorine.
        >
        > "Sulfur hexafluoride is the most potent greenhouse gas the IPCC
        > has evaluated. "
        >
        > All of the other non-CO2 greenhouse gas are more effective at
        trapping
        > heat than CO2.
        >
        > A rise in this emissions will result and impact
        > the climatic processes more so in relation to the aspect that CO2
        has a
        > global
        > warming potential of 1, the lowest of all the GHG, and it takes 50-
        200
        > years for CO2 breakdown in the atmosphere.
        >
        > What would be the quantify or qualifying
        > factors for these non CO2 GHG that have the highest warming
        potential
        > greenhouse gases
        > and are more effective at trapping heat than CO2, and the US levels
        have
        > risen 50%.


        The EPA Inventory of Greenhouse Gas Emissions and Sinks quantifies
        greenhouse gases by the carbon dioxide equivalent. These human-made
        gases are powerful but their volumes are in the billions of parts per
        million (unlike CO2 which is measured in parts per million).

        Nevertheless, these gases to contribute to the warming effect and
        they will remain in the atmosphere indefinitely so they are a big
        problem that is growing larger.

        Mike

        >
        > snip-----
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