OPEN ACCESS
The scientific assessment of shale gas development was compiled by over 200 authors and peer reviewers from around the world. Novel methods of assessment were used, based on the concepts of scenarios, risk and predictive landscape modelling. Three development scenarios were assessed against a baseline sce- nario, across 17 topic-specific chapters. Risk profiles for spatially explicit impacts in distinctive receiving environments were generated and investigated with and without mitigation. Risk was determined by simultaneously considering the consequence of an impact and its likelihood of occurrence, with topic- consequence terms calibrated to ensure a degree of consistency across all topics. A landscape risk model was populated to generate a composite spatial overlay representing the cumulative evolution of the risk profile across the scenarios, representing the full lifecycle of shale gas development activities from initial exploration to final closure and site remediation. For the production-scale scenarios, risk ranges from very high and high before mitigation; to generally moderate after mitigation, assuming that best-practice mitigation is applied and that adequate governance and institutional capacity exists to enforce it. Given the expanse of the study area (171 811 km2) and the relatively small physical surface footprint of shale gas development activities, mitigation best practice is led through application of the mitigation hierarchy, prescribing avoidance of impacts first, largely by adjusting the exact location of wellpads, roads and other structures to not coincide with sensitive surface and geophysical features. Through effective project planning, the majority of sensitive environments in the Central Karoo can be avoided, thus maintaining the social and ecological character and integrity of the region which is so important to many stakeholders. From a cumulative risk perspective, modelling results suggest that shale gas development activities, at the scale expected in the large-scale gas production scenario, may be near to exceeding the development threshold of the Central Karoo given the current paucity of water, skills and infrastructure in the region.
avoidance, hydraulic fracturing, landscape modelling, risk, scenarios, scientific assessment, shale gas development, thresholds
[1] Vengosh, A., Jackson, R.B., Warner, N., Darrah T.H. & Kondash, A., A critical review of the risks to water resources from unconventional shale gas development and hydraulic fracturing in the United States. Environmental Science & Technology, 48(15), pp. 8334–8348, 2014. https://doi.org/10.1021/es405118y
[2] Bradbury, J., Obeiter, M., Draucker, L., Wang, W. & Stevens, A.M., Clearing the air: Reducing upstream greenhouse gas emissions from US natural gas systems. World Resources Institute, 2013.
[3] Drohan, P.J., Brittingham, M., Bishop, J. & Yoder, K., Early trends in landcover change and forest fragmentation due to shale-gas development in Pennsylvania: a potential outcome for the Northcentral Appalachians. Environmental Management, 49(5), pp. 1061–1075, 2012. https://doi.org/ 10.1007/s00267-012-9841-6
[4] Ziemkiewicz, P.F., Quaranta, J.D., Darnell, A. & Wise, R. Exposure pathways related to shale gas development and procedures for reducing environmental and public risk. Journal of Natural Gas Science and Engineering, 16, pp. 77–84, 2014. https://doi.org/ 10.1016/j.jngse.2013.11.003
[5] Christopherson, S. & Rightor, N. 2011. How shale gas extraction affects drilling localities: lessons for regional and city policy makers. Journal of Town & City Management, 2(4), pp. 350–368, 2011.
[6] Small, M.J., Stern, P.C., Bomberg, E., Christopherson, S.M., Goldstein, B.D., Israel, A.L., Jackson, R.B., Krupnick, A., Mauter, M.S., Nash, J. & North, D.W., Risks and risk governance in unconventional shale gas development. Environmental Science & Tech- nology, 48, pp. 8289–8297, 2014. https://doi.org/ 10.1021/es502111u
[7] Academy of Science of South Africa (ASSAf). South Africa’s technical readiness to support the shale gas industry. Pretoria: ASSAf, 2016. https://doi.org/10.17159/assaf.2016/0003
[8] Burns, M., Atkinson, D., Barker, O., Davis, C., Day, L., Dunlop, A., Esterhuyse, S., Hobbs, P., McLachlan, I., Neethling, H., Rossouw, N., Todd, S., Snyman-Van der Walt, L., Van Huyssteen, E., Adams, S., de Jager, M., Mowzer, Z. & Scholes, B., Scenarios and activities. shale gas development in the central karoo: a scientific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[9] De Wit, M.J. The great shale debate in the Karoo. South African Journal of Science,
107(7–8), pp. 2–10, 2011. https://doi.org/10.4102/sajs.v107i7/8.791
[10] CSIR., Strategic environmental assessment for shale gas development. Available at: http://seasgd.csir.co.za/
[11] Wright, J., Bischof-Niemz, T., Carter-Brown, C. & Zinaman, O., Effects on national energy plan- ning and energy security. shale gas development in the central karoo: a scientific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[12] Winkler, H., Altieri, K., Clarke, S., Garland, R.M., Kornelius, G., & Meas, M., Air quality and greenhouse gas emissions. shale gas development in the central karoo: a scientific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[13] Durrheim, R., Doucouré, M. & Midzi, V., Earthquakes. shale gas development in the central karoo: a scientific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[14] Hobbs, P., Day, E., Rosewarne, P., Esterhuyse, S., Schulze, R., Day, J., Ewart-Smith, J., Kemp, M., Rivers-Moore, N., Coetzee, H., Hohne, D., Maherry, A. & Mosetsho, M., Water resources. Shale gas development in the Central Karoo: a scientific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[15] Oelofse, S., Schoonraad, J. & Baldwin, D., Impacts on waste planning and manage- ment. shale gas development in the central karoo: a scientific assessment of the oppor- tunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[16] Holness, S., Driver, A., Todd, S., Snaddon, K., Hamer, M., Raimondo, D., Daniels, F., Alexander, G., Bazelet, C., Bills, R., Bragg, C., Branch, B., Bruyns, P., Chakona, A., Child, M., Clarke, R.V., Coetzer, A., Coetzer, W., Colville, J., Conradie, W., Dean, R., Eardley, C., Ebrahim, I., Edge, D., Gaynor, D., Gear, S., Herbert, D., Kgatla, M., Lamula, K., Leballo, G., Lyle, R., Malatji, N., Mansell, M., Mecenero, S., Midgley, J., Mlambo, M., Mtshali, H., Simaika, J., Skowno, A., Staude, H., Tolley, K., Underhill, L., van der Colff, D., van Noort, S. & von Staden, L., Biodiversity and ecological impacts: landscape processes, ecosystems and species. shale gas development in the central karoo: a scientific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[17] Oettle, N., Lindeque, L., du Toit, J., Samuels, I., Osler, A., Vetter, S. & van Garderen, E.A., Impacts on agriculture. Shale gas development in the central Karoo: a scientific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[18] Toerien, D., du Rand, G., Gelderblom, C. & Saayman, M., Impacts on tourism in the karoo. shale gas development in the central karoo: a scientific assessment of the oppor- tunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[19] Van Zyl, H., Fakir, S., Leiman, T. & Standish, B. Impacts on the Economy. shale gas development in the central Karoo: a scientific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[20] Atkinson, D., Schenk, R., Matebesi, Z., Badenhorst, K., Umejesi, I. & Pretorius, L., Impacts on social fabric. shale gas development in the central Karoo: a scientific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[21] Genthe, B., Maherry, A., Steyn, M., Rother, A., London, L., & Willems, M., Impacts on human health. Shale gas development in the Central Karoo: A scientific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[22] Seeliger, L., de Jongh, M., Morris, D., Atkinson, D., du Toit, K. & Minnaar, J. Impacts on sense of place. shale gas development in the central karoo: a scientific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[23] Oberholzer, B., Lawson, Q., Klapwijk, M., Young, G., Anderson, M. & Orton, J., Visual, aesthetic and scenic resources. shale gas development in the central Karoo: a scientific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Sny- man-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[24] Orton, J., Almond, J., Clarke, N., Fisher, R., Hall, S., Kramer, P., Malan, A., Maguire, J. & Jansen, L., Impacts on heritage. shale gas development in the central karoo: a scien- tific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[25] Wade, A., Jongens, A. & van Niekerk, W., Noise Generated by Shale Gas- Related Activities. Shale Gas Development in the Central Karoo: A Scientific Assessment of the Opportunities and Risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[26] Tiplady, A., van der Merwe, P. & Otto, B., Electromagnetic Interference. Shale gas development in the Central Karoo: a scientific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[27] Van Huyssteen, E., Green, C., Paige-Green, P., Oranje, M., Berrisford, S. & McKelly, D., Impacts on integrated spatial and infrastructure planning. shale gas development in the Central Karoo: a scientific assessment of the opportunities and risks, ed. Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. and de Jager, M. Pretoria: CSIR, 2016. ISBN: 978-0-7988-5631-7.
[28] Scholes, R.J., Schreiner, G.O. & Snyman-Van der Walt, L., Scientific assessments: matching the process to the problem. Bothalia, 47(2), pp. a2144, 2017. https://doi.org/ 10.4102/abc.v47i2.2144
[29] Schreiner, G.O., Snyman-van der Walt, L., De Jager, M., Dludla, A., Lochner, P.A., Wright, J., Scholes, R.J., Atkinson, D. & Hardcastle, P., Advancing a participatory and science- based approach to policy formulation for shale gas development in South Africa. Citizen and other stakeholder participation in unconventional fossil fuel land use decision-making, policy formation, regulatory practice or other governance mechanisms, ed. Whitton, J., Cotton, M. and Brasier, K. London: Routledge, In Press.
[30] Ash, N., Blancom H., Brown, C., Garcia, K., Henrichs, T., Lusas, N., Raudsepp-Hearne, C., Simpson, R.D., Scholes, R., Tomich, T.P., Vira, B. & Zurek, M. (eds)., Ecosystem and human well-being: A manual for assessment practitioners. Washington: Island Press, 2010.
[31] Sohl, T.L. & Sleeter, B.M. Land-use and land-cover scenarios and spatial modeling at the regional scale (No. 2012-3091). US Geological Survey, 2012.
[32] Van Der Heijden, K., Scenarios and forecasting: two perspectives. Technological Fore- casting and Social Change, 65(1), pp. 31–36, 2000. https://doi.org/10.1016/s0040-1625(99)00121-3
[33] Hunt, D.V., Lombardi, D.R., Atkinson, S., Barber, A.R., Barnes, M., Boyko, C.T., Brown, J., Bryson, J., Butler, D., Caputo, S. & Caserio, M., Scenario archetypes: Con- verging rather than diverging themes. Sustainability, 4(4), pp. 740–772, 2012. https://doi.org/10.3390/su4040740
[34] Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES)., Sum- mary for policymakers of the assessment report of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services on pollinators, pollination and food production. Potts SG, Imperatriz-Fonseca VL, Ngo HT, Biesmeijer JC, Breeze TD, Dicks LV, Garibaldi LA, Hill R, Settele J, Vanbergen AJ. (eds). Bonn: Secretariat of the Inter- governmental Science-Policy Platform on Biodiversity and Ecosystem Services. 2016.
[35] Alcamo, J. & Henrichs, T., Chapter two towards guidelines for environmental scenario analysis. Developments in Integrated Environmental Assessment, 2, pp. 13–35, 2008. https://doi.org/10.1016/s1574-101x(08)00402-x
[36] Intergovernmental Panel on Climate Change (IPCC). Annex II: Glossary [Mach, K.J., S. Planton and C. von Stechow (eds)]. Climate Change 2014: Synthesis Report. Contri- bution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovern- mental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds)]. Geneve: IPCC, pp. 117–130, 2014.
[37] Scholes, R., Lochner, P., Schreiner, G., Snyman-Van der Walt, L. & de Jager, M. (eds.), Shale gas development in the Central Karoo: a scientific assessment of the opportunities and risks. CSIR/IU/021MH/EXP/2016/003/A, ISBN 978-0-7988-5631-7, Pretoria: CSIR, 2016.
[38] South Africa. National Environmental Management Act No. 107 of 1998. Pretoria: South African Government, 1998.