Geological Risk Classification

Leakage within CCS context is simply the release of captured and stored or trapped CO2 back into the atmosphere. CO2 leakage risks associated with geological formation could have consequence on either a global or a local scale. This simplistic risk stratification is crucial in helping to explain and understand the impact on CDM projects. This section will be used to explain the two generic risks associated with geological carbon storage as illustrated in Figure 30 below forming the bases for understanding the relevance of risk assessment and management in the process of CCS implementation under the CDM framework.

5.2.1 Localised Risk

With CO2 leaking out of geological storage formation, an increased concentration of the gas in the immediate environment (i.e. earth surface and the shallow subsurface) is possible, local impacts may exist for human ecosystems, ground water and ocean (food supply) because of the imbalance in the level of atmospheric gases.⁴⁶⁹ Leaks to the immediate surrounding could be gradual or sudden. The possibility of a sudden or gradual leakage happening could be the consequence of failure in the storage seal or injection well, accidental puncture of the reservoir by the drilling of wells, seismic activities, faults or fractures.⁴⁷⁰ The degree of impact invariably depends on firstly the level of toxic impurity in the CO2, the atmospheric and topological conditions of the area, the rate of release which affects the

concentration levels and the volume of the leak.⁴⁷¹

468Infra note AIRMIC, ALARM, IRM 2002.

469Rubin, E., 2006, “IPCC Special Report on Carbon Dioxide Capture and Storage”, RITE International Workshop on CO₂ Geological Storage, Tokyo Japan. 20 February 2006.

470Id. and Pollak M., et al., 2009, “Risk Governance for geological Storage of CO₂ under the Clean Development Mechanism”, Climate Policy 9, (2009) 71-87.

471 Murphy et al., 2008, “Geological Carbon Storage: The Role of Government and industry in Risk Management”, Innovation, science and Environment: Canadian Policies and

176 Under this categorisation of risk, human health risk could affect the general public or the employees. There is also the potential for properties to be at risk due to damage, reduced valuation and possible disruption of economic activities within the local area could result in liability issues for the operators.⁴⁷² When considering liability issues, this category clearly delineate risks within the framework of the human health risk, environmental risks, property risks and financial risk regulation.⁴⁷³ Box 2 explains the impact of localised risk on a community in Cameroun consequent to a leak from the earth in 1986.

5.2.2 Global Risk

The possibility for CO2 to leak from pipeline or geological storage site into the atmosphere (related to infrastructural faults, human error or seismic activity) results in greenhouse effects. Once there is a compromise to the transportation infrastructure and geological storage, the release of CO2 into the atmosphere effectively negates the goal of CCS and the overall climate change mitigation strategy. Also, CCS technology implementation is highly energy intensive which could result in a higher than expected energy penalty.⁴⁷⁴

Carbon dioxide emitted as a result of fossil fuel usage during CCS projects with any leakage as a result of flaws in storage procedure and sites will result in net increase in [global] CO2 emissions.⁴⁷⁵ The release of CO2 could contribute significantly to climate change if there is protracted leak from the storage

formation to the atmosphere. Continuous leakage has the potential to in part offset the climate benefit of CCS. IPCC (2005) concluded that carefully selected,

designed and managed geological storage site have the capacity to retain over 99%

of the stored CO2 underground over a hundred years period.⁴⁷⁶

The IPCC 2005 report further provided some insight into the magnitude of local and global risks associated with geological storage. Concluding effectively that, Performance, 2008-2009 (edited by Glen Toner). Published for The School of Public Policy and Administration Carleton University by McGill-Queen’s University Press, 2008

472 Wilson et al., 2008, IRGC Policy Brief 2008, Regulation of Carbon Capture and Storage, Available online at www.irgc.org/Expert-contributions-and-workshop.html

473Id.

474Herzog et al 2004, “Carbon Capture and Storage from Fossil Fuel Use” Encyclopedia of Energy, Vol. 1 Copyright 2004, Elsevier. All rights reserved.

475Id. Murphy et al., 2008

476 IPCC 2005, Summary For Policymakers, pg. 12

177

“local health, safety and environmental risks would be comparable to the risks of current activities such as natural gas storage, EOR, and deep underground disposal of acid gas.”⁴⁷⁷ Whilst in the case of global risk, “observations from engineered and natural analogous as well as models suggest that the fraction retained…is very likely to exceed 99% over 100 years and is likely to exceed 99% over 1000

years.”⁴⁷⁸

477Id.

478Id. , Summary for Policymakers, pg.14. The use of the term “very likely” was expressed to imply the probability between 90 and 99 per cent; while “likely” indicates a probability between 66 and 90 per cent. As cited in Murphy et al., 2008 Geological Carbon Storage:

The Role of Government and Industry in Risk Management”

178

(a) (b)

Box 2 Effect of CO2 Leakage to Environment

The Lake Nyos experience is often cited as an example of the impact of CO2

release to the atmosphere and local ecology hence giving it the name "Deadliest lake" by Guinness World Records in 2008. CO2 is beneficial to life on earth at a concentration of 0.05-0.08% over an atmospheric background concentration of 0.037% but higher level of exposure to this gas could prove to be injurious and as in the case of the Lake Nyos fatal to the living organisms around the area.

Prolonged exposure to concentration of 20 – 30% can result in the death of air breathing animals while single celled organisms and microbes can survive 50 and 100% concentrations respectively.

On 21^st of August 1986, the volcanic Crater Lake Nyo in the North Western region of Cameroun suddenly released CO2 from magmatic sources into the surrounding area and water. The leaked CO2 was claimed to be responsible for the deaths of around 1700 people in Cameroon, West Africa. Clinical findings in 845 survivors seen at or admitted to hospital were compatible with exposure to an asphyxiant gas. Rescuers noted cutaneous erythema and bullae on an unknown proportion of corpses and 161 (19%) survivors treated in hospital; though these lesions were initially believed to be burns from acidic gases, further investigation suggested that they were associated with coma states caused by exposure to carbon dioxide in air. The disaster at Lake Nyos and a similar event at Lake Monoun, Cameroon, two years previously provide new information on the possible medical effects of large scale emissions of carbon dioxide, though the presence of other toxic factors in these gas releases cannot be excluded.

In similar exposure of fauna and flora to large emission of CO2, in 1989, the volcanic Mammoth Mountain in the United States experienced seismic activities which resulted in the seepage of CO2 into the surrounding. In 1990, authorities in California reported the death of trees on 100 acres of land around the volcanic Mammoth Mountain and concluded that the deaths were caused by exposure of the roots to high concentration of CO2.

The Figures 28(a & b) below shows the crater lake of Nyos and dead a livestock nearby as a result of the CO2 release into the atmosphere While Figure 28c shows the impact of the release to the Mammoth Mountain in California.

Box 1 Effect of CO2 Leakage to Environment

The Lake Nyos experience is often cited as an example of the impact of CO2

release to the atmosphere and local ecology hence giving it the name "Deadliest lake" by Guinness World Records in 2008. CO2 is beneficial to life on earth at a concentration of 0.05-0.08% over and atmospheric background concentration of 0.037% but higher level of exposure to this gas could prove to be injurious and as in the case of the Lake Nyos fatal to the living organisms around the area.

According to Benson et al. (2002) prolonged exposure to concentration of 20 – 30% can result to the death for air breathing animals while single celled organisms and microbes can survive 50 and 100% concentrations respectively On 21^st of August 1986, the volcanic crater Lake Nyo in the North Western region of Cameroun suddenly released CO2 from magmatic sources into the surrounding area and water. The leaked CO2 was claimed to be responsible for the deaths of around 1700 people in Cameroon, West Africa. Clinical findings in 845 survivors seen at or admitted to hospital were compatible with exposure to an

179 Figure 28(a, b &c) Area reported with trees dying in Mammoth Mountain area of California. Sources: United States Geological Society website

Figure 10c Area reported with trees dying in Mammoth Mountain area of California.

Sources: United States Geological Society website

Figure 29 Life-cycle of a geological sequestration project for CO2 will involve four phases. In addition to the operator of a site and the financial and insurance organizations that support the project, two different government entities have a role. In order to avoid potential conflicts of interest, the regulatory organization responsible for reviewing and approving the creation of a site, monitoring its operation, and certifying its satisfactory closure should be separate from the government entity that ultimately assumes responsibility for long-term stewardship.

180

Figure 30 An illustration of the broad characterisation of geological Carbon storage risks.

Adapted from Wilson et al 2003 Taxonomy of risk of geological sequestration

Figure 12 An illustration of the broad characterisation of geological Carbon storage risks.

Adapted from Wilson et al 2003 Taxonomy of risk of geological sequestration