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Planned coal to gas transition will DOUBLE Australian electric power greenhouse gas (GHG) pollutionby Open-Publishing - Sunday 15 May 2011
Australia is a world leader in annual per capita greenhouse gas (GHG) pollution, coal exports and Liquid Natural Gas (LNG) exports. Thus Australia’s annual per capita Domestic plus Exported GHG pollution is 60 times the annual per capita GHG pollution of Bangladesh. The extreme right wing, pro-coal, pro-gas Australian Labor Government is proposing a Carbon Tax and says that a major consequence will be a coal to gas transition for fossil fuel burning for electric power. However, as set out below, a coal to gas transition will in actuality double the GHG pollution from electricity generation because methane (CH4, a major constituent of natural gas) leaks and is 105 times worse than carbon dioxide (CO2) as a GHG on a 20 year time scale. .
Methane (CH4) (about 85% of natural gas) is 105 times worse than CO2 as a greenhouse gas (GHG) on a 20 year time frame and taking aerosol impacts into account. Methane leaks (3.3% in the US based on the latest US EPA data and as high as 7.9% for methane from “fracking” coal seams). Using this information one can determine that burning for electricity is much dirtier than coal burning greenhouse gas-wise (GHG-wise). While gas burning for power generates twice as much electrical energy per tonne of CO2 produced (MWh/tonne CO2) than coal burning and the health-adverse pollution from gas burning is lower than for coal burning, gas leakage in the system actually means that gas burning for power is worse GHG-wise than coal burning.
Unfortunately pro-gas politicians and gas producers variously add to the popular misconceptions that “gas is clean energy ” or “gas is cleaner energy than coal”. While pricing any bad item (e.g. coal burning, smoking, drinking) is useful the devil is in the detail as to any desired Carbon Price and Carbon Tax as a market-based GHG pollution mitigation mechanism. Thus the Australian Government has made it clear that a significant intent of its proposed Carbon Tax is to promote a coal to gas transition. However, as set out below, a coal to gas transition will be disastrous, involving huge national investments to achieve an increase in GHG pollution.
The current global Gas Boom, Gas Rush and Gasland perversion is enabled by corporate greed, lobbying and the falsehoods that “gas is clean” or that “gas is cleaner than coal”. Methane (CH4) is a major greenhouse gas (GHG) that on a 100 year time scale has a relative global warming potential (GWP) that is 25 times that of carbon dioxide (CO2). However a re-assessment by US scientists that takes atmospheric aerosol responses to CH4 into account has found that on a 20 year time scale CH4 is 105 times worse than CO2 as a GHG. Recent data from the US EPA indicates that the industrial leakage of CH4 in the US is 3.3%. Using this information it can be estimated that gas burning for power can be much dirtier GHG-wise than coal burning.
Dr Drew Shindell and colleagues (NASA’s Goddard Institute for Space Studies) have published a paper in the prestigious scientific journal Science (US) that takes gas-aerosol interactions into account in assessing the GWP effectiveness of various GHGs as summarized in the Abstract of their paper : “Evaluating multicomponent climate change mitigation strategies requires knowledge of the diverse direct and indirect effects of emissions. Methane, ozone, and aerosols are linked through atmospheric chemistry so that emissions of a single pollutant can affect several species. We calculated atmospheric composition changes, historical radiative forcing, and forcing per unit of emission due to aerosol and tropospheric ozone precursor emissions in a coupled composition-climate model. We found that gas-aerosol interactions substantially alter the relative importance of the various emissions. In particular, methane emissions have a larger impact than that used in current carbon-trading schemes or in the Kyoto Protocol. Thus, assessments of multigas mitigation policies, as well as any separate efforts to mitigate warming from short-lived pollutants, should include gas-aerosol interactions.” .
The key technical quote from Shindell et al. (2009) provides an estimate that the GWP of CH4 relative to CO2 on a 20 year time scale is 79 (without aerosol effects) and 105 (with aerosol effects considered): “Fig.2. The 100-year GWPs for methane, CO, and NO x (per Tg N) as given in the [IPCC] AR4 and in this study when including no aerosol response, the direct radiative effect of aerosol responses, and the direct+indirect radiative effects of aerosol responses. The AR4 did not report uncertainties for methane or CO and gave no mean estimate for NO x . The range for the GWP of CO is from the third IPCC assessment and encompasses values reported up through the AR4. Our calculations for the shorter 20-year GWP, including aerosol responses, yield values of 79 and 105 for methane, 11 and 19 for CO, and –335 and –560 for NO x , including direct and direct+indirect radiative effects of aerosols in each case. The 100-yr GWPs for SO 2 (per Tg SO 2 ) and ammonia would be –22 and –19, respectively, including direct aerosol radiative effects only, and –76 and –15 adding indirect aerosol radiative effects. GWPs for very short-lived NO x , SO 2 , and ammonia will vary widely by emission location and timing, and hence global values are of limited use.” [2, 3]
The Nature News part of the prestigious scientific journal Nature (UK) has summarized the key findings of Shindell and colleagues as follows: “Aerosols’ complicated influence on our climate just got more threatening: they could make methane a more potent greenhouse gas than previously realized, say climate modellers. Drew Shindell, at NASAGoddard Institute for Space Studies, New York , and colleagues ran a range of computerized models to show that methane’s global warming potential is greater when combined with aerosols — atmospheric particles such as dust, sea salt, sulphates and black carbon. The International Panel on Climate Change (IPCC) and treaties such as the Kyoto Protocol assume methane to be, tonne-for-tonne, 25 times more potent than carbon dioxide at warming the planet. But the interaction with aerosols bumps up methane’s relative global warming potential (GWP) to about 33, though there is a lot of uncertainty around the exact figure.” .
Dr Shindell (NASA Goddard Institute for Spaces Studies, New York ) has given a succinct summary of these findings: “What happens is that as you put more methane into the atmosphere, it competes for oxidants such as hydroxyl with sulphur dioxide. More methane means less sulphate, which is reflective and thus has a cooling effect. Calculations of GWP [Global Warming Potential;] including these gas-aerosol linkages thus substantially increase the value for methane.” .
This re-assessment upwards of the GWP of CH4 to be 105 times that of CO2 on a 20 year time scale must have a big effect on assessment of total annual GHG pollution and the urgency with which this is addressed.
Thus based on a 20 year time scale CH4 GWP relative to CO2 of 72, World Bank analysts have estimated that global livestock production contributes over 51% of total annual global GHG pollution that they have re-assessed upwards from 41.8 billion tonnes CO2-e (CO2 equivalent) to 63.8 billion tonnes CO2-e. .
Further, based on a CH4 GHG contribution 25 times bigger than that of CO2 (on a 100 year time scale), eminent climate scientist Professor Hans Joachim Schellnhuber CBE (Director of the Potsdam Institute for Climate Impact Research [PIK], Germany) has estimated that for a 67% chance of avoiding a catastrophic 2 degree Centigrade temperature rise (the EU target; would you board a plane if it had a 33% chance of crashing?) the World has to cease CO2 emissions by 2050. “All men are created equal” means that all human beings must be allotted equal shares of CO2 pollution until 2050. This in turn means that high annual per capita GHG pollution countries such as the US and Australia must reach zero CO2 emissions by 2020 while low per capita emitters (e.g. India and Burkina Faso) can increase their emissions until finally reaching zero emissions by 2050. .
Similarly, based on CH4 being 25 times worse than CO2 as a GHG, Dr Vicky Pope (Head of Climate Change Advice, UK Met Office Hadley Centre): “Latest climate projections from the Met Office Hadley Centre show the possible range of temperature rises, depending on what action is taken to reduce Greenhouse gas emissions. Even with large and early cuts in emissions, the indications are that temperatures are likely to rise to around 2 °C above pre-industrial levels by the end of the century. If action is delayed or not quick enough, there is a large risk of much bigger increases in temperature, with some severe impacts. In a worst-case scenario, where no action is taken to check the rise in Greenhouse gas emissions, temperatures would most likely rise by more than 5 °C by the end of the century. This would lead to significant risks of severe and irreversible impacts. In the most optimistic scenario, action to reduce emissions would need to start in 2010 and reach a rapid and sustained rate of decline of 3 per cent every year. Even then there would still only be a 50-50 chance of keeping temperature rises below around 2°C. This contrasts sharply with current trends, where the world’s overall emissions are currently increasing at 1 per cent every year.” .
On the same CH4 GWP assumptions, Professor Kevin Anderson and Dr Alice Bows (Tyndall Centre for Climate Change Research, University of Manchester, Manchester, UK) concluded: “According to the analysis conducted in this paper, stabilizing at 450 ppmv [carbon dioxide equivalent = CO2 -e, atmospheric concentration measured in parts per million by volume] requires, at least, global energy related emissions to peak by 2015, rapidly decline at 6-8% per year between 2020 and 2040, and for full decarbonization sometime soon after 2050 …Unless economic growth can be reconciled with unprecedented rates of decarbonization (in excess of 6% per year), it is difficult to envisage anything other than a planned economic recession being compatible with stabilization at or below 650 ppmv CO2-e ... Ultimately, the latest scientific understanding of climate change allied with current emissions trends and a commitment to “limiting average global temperature increases to below 4 o C above pre-industrial levels”, demands a radical reframing of both the climate change agenda, and the economic characterization of contemporary society.” .
In short, the re-assessment that CH4 is 105 times worse than CO2 as a GHG on a 20 year time scale means that (a) the annual GHG must be well over 50% greater than hitherto thought and (b) the time for 100% economic decarbonization must be substantially less than the current expert estimate of about 40 years.
A key aspect of economic decarbonization is obviously an urgent shift to non-polluting renewable energy (wind, wave, tide, concentrated solar thermal and solar photovoltaic) and geothermal energy. However this transition has been falsely obfuscated by fossil fuel corporations and their associates in the Western Lobbyocracies who falsely assert that “gas is clean energy” or that “gas is cleaner energy” than coal burning and are hell-bent on a transition from coal burning to gas burning for power. As a result of these false assertions there is currently a major Gas Boom and Gas Rush around the world that is set to become a global Gasland (see the movie “Gasland”).
Professor Robert Howarth (Cornell University) has considered the consequences of a 1.5% industrial methane leakage and a CH4 global warming potential 72 times that of CO2 on a 20 year time scale and has concluded: “A complete consideration of all emissions from using natural gas seems likely to make natural gas far less attractive than oil and not significantly better than coal in terms of the consequences for global warming …Far better would be to rapidly move toward an economy based on renewable fuels. Recent studies indicate the U.S. and the world could rely 100% on such green energy sources within 20 years if we dedicate ourselves to that course. ” .
I have done simple calculations showing that a 3.7% leakage of CH4 and a CH4 GWP 72 times that of CO2 yields that same greenhouse gas effect as burning the 96.3% remaining CH4 i.e. a roughly doubled GHG emissions from gas burning  . However assessment of recent US EPA data indicates a methane leakage rate in the US of 3.3% [13, 14] and, as outlined above, the global warming potential of CH4 on a 20 year time scale is 105 relative to CO2 if the impact on global-dimming aerosols is included.
I have accordingly performed a re-calculation of the gas burning greenhouse gas effect based on these updated assessments as outlined below .
(1) Methane (CH4) is dirty energy - burning CH4 yields carbon dioxide (CO2).
CH4 has a molecular weight of 16, carbon dioxide (CO2) has a molecular weight of 44 and carbon (C) has an atomic weight of 12.
When you burn CH4 you get CO2: CH4 + 2O2 -> CO2 + 2 H2O.
Accordingly burning 16 g of CH4 (1 mole CH4; 6.022 x 1023 molecules of CH4) yields 44 g of CO2 (1 mole CO2; 6.022 x 1023 molecules of CO2); burning 100 g of CH4 yields 100x 44/16 = 275 g of CO2; burning 100 tonnes of CH4 yields 100x 44/16 = 275 tonnes of CO2; and burning 1 tonne of CH4 yields 44/16 = 2.75 tonnes CO2.
In comparison, burning 12g black coal (mostly carbon, C, atomic weight 12: C + O2 -> CO2) yields 44 g CO2 (1 mole CO2) ; burning 100 tonnes of C yields 100 x 44 tonne /12 = 366.7 tonnes CO2; and burning 1 tonne of C yields 3.7 tonnes CO2.
Brown coal is about 65% water (H2O) and accordingly burning 100 tonnes of brown coal yields 0.35 x 366.7= 128.3 tonnes CO2; and burning 1 tonne of brown coal yields 1.3 tonnes CO2.
(2) CH4 is 105 times the Global Warming Potential (GWP) of CO2 (20 year time frame, aerosol impacts included).
WP CH4 is 105 times the Global Warming Potential (GWP) of CO2 (as assessed on a 20 year time frame with atmospheric aerosol impacts included).
This means that the GWP of 1 mole CH4 (16 g) is 105 times that of 1 mole of CO2 (44 g).
Thus 16 g CH4 has the GWP of 105 x 44 g CO2 = 4,620 g CO2 i.e. 1 g CH4 has the GWP of 4,620/16 = 288.8 g CO2 or of CO2-e (CO2 equivalent); and 1 tonne CH4 has the GWP of 288.8 tonnes CO2-e.
(3). CH4 leaks (US average 3.3% ). What percent (%) CH4 leakage gives the same greenhouse gas (GHG) effect as burning the remaining CH4?
If there is industrial leakage of CH4 then one must consider the greenhouse gas effect of the released methane (105 times worse than CO2 as a greenhouse gas on a 20 year time scale).
Of 100 moles of CH4, how much CH4 leakage (y moles) gives the same greenhouse effect (in CO2 equivalents or CO2-e) as burning the remaining CH4?
y moles CH4 x (105 moles CO2-e/mole CH4) = (100-y) moles CH4 x (1mole CO2-e/ mole CH4).
105y moles CO2-e = (100-y) moles CO2-e
105y = 275 – 2.75y
107.75y = 275
y = 275/107.75 = 2.55 i.e. a 2.6% leakage of CH4 yields that same greenhouse effect as burning the remaining 97.4% of the CH4 .
This result has been checked for the fate of 100 moles of CH4: 2.55 moles leaked CH4 corresponds to 2.55 moles CH4 x 105 moles CO2-e/ mole CH4 = 268 moles CO2-e . Burning the remaining 97.4 moles of CH4 corresponds to 97.4 moles CH4 x 2.75 moles CO2/moleCH4 = 268 tonnes CO2.
(4) What does this mean when we compare the greenhouse gas dirtiness of gas-burning or coal-burning for power?
The Global Warming Potential (GWP) of methane (CH4) is 105 relative to that of an equal number of molecules (NOT an equal mass) of carbon dioxide (CO2) on a 20 year time scale and taking aerosol impacts into account.  This makes the gas versus coal situation even worse as the following calculations show.
1 mole (16g) of methane (CH4) has 105 times the greenhouse gas (GHG) effect as 1 mole (44g) of carbon dioxide (CO2) and, accordingly, 1 tonne leaked CH4 has the GWP of 105 x 44/16 = 288.8 tonnes CO2-equivalent.
Burning 1 mole CH4 (16 g CH4) yields 1 mole CO2 (44 g CO2) and accordingly burning 1 tonne CH4 yields 44/16 = 2.75 tonne CO2. Burning 12 tonne carbon (C; atomic weight 12) yields 44 tonne CO2 and hence burning 1 tonne C yields 44/12 = 3.7 tonne CO2.
Burning natural gas for power yields roughly twice the electrical energy per tonne of CO2 released as burning coal for power. Thus for power stations in in Victoria , Australia, gas-fired power stations (0.60 – 0.90 tonnes CO2-e/MWh) are roughly twice as efficient GHG-wise in producing energy as brown coal-burning power stations (1.21-1.53 tonnes CO2-e/MWh) .
Thus while burning 16 tonnes CH4 yields the same amount of CO2 (44 tonnes CO2) as burning 12 tonnes of coal (C), in practice in terms of energy production (measured in MWh, megawatt hours) burning 8 tonnes gas (CH4) yields the same energy as burning 12 tonnes coal (C) i.e. in a coal-to-gas transition 1 tonne of coal (C) can be replaced by 8/12 = 0.67 tonnes gas.
Burning 67 tonnes CH4 (circa 85% of natural gas) yields 67 x 2.75 = 184 tonnes CO2 and about the same electrical power as burning 100 tonnes coal (C) which yields 366.7 tonnes CO2.
However, based on the latest US EPA data the CH4 leakage in the US is 3.3%  and hence, remembering that 1 tonne CH4 has the GWP of 288.8 tonnes CO2-e (see (2) above), using 67 tonnes CH4 to generate electrical power yields 0.033 x 67 tonnes CH4 x 288.8 tonnes CO2-e/tonne CH4 = 638.5 tonnes CO2-e (from the 3.3% leaked CH4) PLUS 0.967 x 67 tonnes CH4 x 2.75 tonnes CO2/ tonne CH4 = 178.2 tonnes CO2 (from the burning of the remaining 96.7% of CH4) i.e. a total of 638.5 + 178.2 = 816.7 tonnes CO2-e.
Accordingly, with 3.3% system CH4 leakage, replacing burning 100 tonnes of coal with burning CH4 results in a net CO2-e pollution of 816.7 - 366.7 = 450 tonnes CO2-e i.e. a coal to gas transition is dirtier by 4.5 tonnes CO2-e for every 1 tonne of coal replaced. Thus at 3.3% leakage using gas for electrical power is much dirtier greenhouse gas-wise (GHG-wise) than burning coal.
According to Professor Robert Howarth fugitive emissions from CH4 leakage are 1.7-6.0% for conventional gas and 3.6-7.9% for shale gas (e.g. from “fracking”)  . Accordingly using 67 tonnes of conventional gas to replace the burning of 100 tonnes of coal to generate electricity actually yields 510.0 -1,334.2 .tonnes CO2-equivalent and using shale gas actually yields 874.2 - 1,698.3 tonnes CO2-equivalent i.e an extra 143.3 - 967.5 tonnes CO2-equivalent and 507.5 - 1,331.6 tonnes CO2-equivalent, respectively.
Accordingly, these latest estimates of the Global Warming Potential (GWP) of methane relative to CO2 on a 20 year scale (105) and of methane leakage (3.3%) indicate that gas burning for power can be much dirtier greenhouse gas-wise (GHG-wise) than coal burning. On these estimates a stationary energy sector transition from coal burning to gas burning to reduce GHG pollution is strongly contra-indicated. Gas burning for power can be much dirtier greenhouse gas-wise (GHG-wise) than coal burning.
(5). Coal to gas transition for electricity in Australia would double electricity generation greenhouse gas (GHG) pollution.
The Australian Labor Government proposes a Carbon Tax and has adumbrated a consequential coal to gas transition for electrical power generation on the mistaken assumption that "gas is cleaner than coal". In 2009 Australia consumed 135.8 million tonnes of coal . In 2009 Australian power stations generated 208 million Megawatt hours (MWh) of electricity and generated 181 million tonnes CO2-e of greenhouse gas, about 90% of this deriving from coal-fired power plants . Accordingly, Australia’s annual coal burning for power is 0.9 x 181 million tonnes CO2-e x 12 tonnes coal (C)/ 44 tonnes CO2 = 44.0 million tonnes coal. A coal-to-gas transition for electricity generation (and assuming 3.3% gas leakage) would add 4.5 tonnes CO2-e for every tonne of coal replaced (see (4) above) and hence yield an extra 44 million tonnes coal x 4.5 tonnes CO2-e/ tonne coal = 198 million tonnes CO2-e PLUS 181 million tonnes CO2-e = 379 million tonnes CO2-e i.e. TWICE the present pollution from electricity generation.
Notwithstanding the science, the fossil fuel industry and allied lobbyists, commentators and politicians in the Western Lobbyocracies and Murdochracies continue to promulgate the falsehoods that “gas is clean energy” or that “gas is cleaner energy than coal”, most notoriously so in Australia, a world leader in per capita greenhouse gas pollution, coal exports and liquid natural gas (LNG) exports. .
Decent people around the world must (a) inform everyone they can that gas is dirty energy, that gas burning for power can be much dirtier greenhouse gas-wise (GHG-wise) than coal burning and (b) resolutely, through voting, sanctions and boycotts, eschew any avoidable dealings with countries, corporations, people and politicians involved in the worsening, terracidal Gas Boom, Gas Rush and Gasland perversion. Please tell everyone you can – a coal to gas transition will cripple timely implementation of 100% renewable energy, stop realization of zero CO2 emissions by 2050 and prevent the return of atmospheric CO2 concentration from the current dangerous and damaging 392 ppm to the 300 ppm required for a safe planet for all peoples and all species. .
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