Greenhouse gas emissions

The production, burning and export of CSG for energy may be little or no better for our climate future than coal.

  • Coal seam gas (CSG) is “unconventional” gas, a fossil fuel that adds to greenhouse pollution.
  • The gas industry claims gas-fired power stations produce 70% less CO2 than existing coal-fired power stations.[i] This figure only refers to the emissions released when the gas is burnt. It does not include the emissions involved in producing the gas – the drilling, fracking, compressing, pumping, liquefying and transporting the gas; nor the loss of carbon-storing forests and woodlands cleared to make way for gas wells and pipes.
  • The substantial leaks of gas to atmosphere before combustion are not included in the 70% figure.  Methane is the major component of both natural and coal seam gas. It is a much more potent greenhouse gas than CO2, 72 times more effective at trapping heat in the atmosphere over a period of 20 years, or 25 times more effective over 100 years. [ii]
  • Liquefying natural gas consumes at least 20% of its energy value and cancels almost 30% of its “clean” character.[iii]
  • Queensland is the largest producer of greenhouse gases in the country[iv] and by far the highest per capita emitter.[v]
  • The total emissions per year from 3 LNG projects approved in Queensland amounts to 24.14 million tonnes of CO2 equivalent (CO2-e)[vi] - excluding the emissions from burning the exported gas. The CSG industry will increase Queensland’s emissions by 21% over the next 3-5 years. The Queensland Curtis Island LNG project alone will generate 95 million tonnes of CO2-e during its construction and 20 year operational life.[vii]
  • “The EISs of four CSG companies exporting LNG out of Gladstone suggest their cumulative annual emissions in Australia at peak production will be 35 million tonnes of carbon dioxide equivalent. If the updated global warming factor for methane over 100 years (32 tonnes equivalent) is adopted then this rises to 53 million tonnes of carbon dioxide equivalent a year. The use of the warming factor for methane over the 20-year horizon (105 tonnes equivalent) gives 175 million tonnes a year.” [viii]
  • The Queensland government wants to export 50 million tonnes of LNG per annum.[ix] When burnt, this will generate 140 million tonnes of CO2 equivalent a year.[x]
  • Total greenhouse gas emissions due to hydraulic fracturing for shale gas production have been estimated at 33.6 tonnes of CO2 equivalent per gigawatt hour (t CO2-e/GW.h) or about 62% more than for diesel and petroleum (approximately 20.3t CO2-e/GW.h)[xi]
  • Monitoring of methane leakage in the oil and gas industry is limited, but conservative estimates suggest that during the life cycle of an average unconventional gas well, 3.6 – 7.9% of total production is emitted to the atmosphere as methane. This is at least 30% and perhaps more than twice as great as the life cycle methane emissions for conventional (natural) gas which range from 1.7 – 6%.[xii]

References

[i] APPEA CSG Factsheet #4, Environment.  Accessed 22/12/10 fromhttp://www.appea.com.au/images/stories/mb_files/CSG_environment.pdf

[ii] IPCC 4th assessment report www.ipc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter2.pdf Accessed 19/12/11

[iii] http://www.peakoil.org.au/Heede.lng.greenhouse-intensity.pdf  Accessed 20/4/11

[iv] Courier Mail, June 24th 2008. Queensland largest greenhouse gas emitter in countryhttp://www.couriermail.com.au/news/features/states-gas-emissions-surge/story-e6freowx-1111116723526

[v] Queensland’s greenhouse gas emissions 2005 http://www.climatechange.qld.gov.au/pdf/climateqreport/climateqreport-chapter3.pdf

[vi] Figures from Santos,http://www.glng.com.au/library/EIS/0c%20Executive%20Summary%20(Section%20ES)%20FINAL%20PUBLIC.pdfQGC/BG http://qclng.com.au/uploads/docs/Queensland_Curtis_LNG_Project_IAS.pdf and Originhttp://www.dip.qld.gov.au/resources/project/aplng/eis-executive-summary.pdf
Environmental Impact Statements. All accessed 22/12/10

[vii] Queensland Curtis LNG Environmental Impact Statement.

http://qclng.com.au/uploads/docs/Queensland_Curtis_LNG_Project_IAS.pdf

[viii] Dr Colin Hunt http://theconversation.edu.au/coal-gas-seams-good-until-you-measure-the-methane-4490Accessed 16/12/11

[ix] Premier Anna Bligh, media release 28/8/09. “Multi-billion dollar Gladstone LNG projects a step closer.”

[x] Energy Strategies Ltd calculate 1 tonne LNG generates 2.8 tonnes CO2.

[xi] Howarth, R.W., Santoro, R., & Ingraffea, A. Methane and the greenhouse-gas footprint of naturalgas from shale formations. Cornell University, 2011.http://www.sustainablefuture.cornell.edu/news/attachments/Howarth-EtAl-2011.pdf  Accessed 28/11/11

[xii] Howarth, R.W., Santoro, R., & Ingraffea, A. Methane and the greenhouse-gas footprint of naturalgas from shale formations. Cornell University, 2011.http://www.sustainablefuture.cornell.edu/news/attachments/Howarth-EtAl-2011.pdf  Accessed 28/11/11

Further reading