FROZEN HEAT | Volume 2

tional vulnerabilities, such as inadequate capacity and rapid demand growth. In many low-income countries with similar lack of sufficient energy resources, supply and demand vul- nerabilities overlap, making them especially insecure. Enhanced energy security for regions can be achieved by great- er use of domestic energy sources and by increasing the diver- sity and resilience of energy systems. As an additional primary energy source, gas hydrate development could increase the di- versity and domestic share of primary energy in many parts of the world, potentially decreasing import dependency. Oil ranks ahead of electricity in terms of final energy con- sumption and remains the world’s dominant form of energy supply to the broader economy, making it essential to energy security (IEA 2008; Chang and Liang Lee 2008). Supply concerns for natural gas are mostly regional, due to the lim- ited role of natural gas in global trade. However, the trade in liquefied natural gas increasingly connects natural gas mar- kets globally. The transition toward gas usage in electricity generation could result in greater energy security concerns because of the increased dependence on imports. Gas hydrates appear to be widely distributed around the world and are, therefore, very attractive to countries not natu- rally endowed with conventional domestic energy resources. As gas hydrate resources occur in proximity to many of the world’s largest and most rapidly growing economies – such as China, India, Japan, and the United States – they pro- vide opportunities to improve energy security by reducing these countries’ reliance on energy imports. Globally, this increased measure of self-sufficiency can have a mitigating effect on potential future discord resulting from competition for access to external energy sources. 1.5.3 ENVIRONMENTAL IMPACT Methane is a powerful greenhouse gas. Natural gas extrac- tion and gathering activities lead directly to methane emis- sions through leakages during drilling, completion and stimulation activities. in transportation pipelines and other infrastructure. The scale of these impacts in unconventional gas extraction is not well known, nor is it clear whether gas hydrate production will have similar effects. Monitoring and

assessment of such potential emissions, therefore, have been identified as key priorities of initial gas hydrate field evalu- ation programs (Arata et al. 2011). Further, gas transmis- sion and distribution introduce significant potential fugitive methane emissions, and these issues would be no different regardless of the whether the gas was derived from conven- tional or unconventional sources. When gas-hydrate-derived methane is combusted, it pro- duces carbon dioxide, just as any hydrocarbon would. It will, therefore, contribute to carbon emissions. However, the amount of carbon dioxide per unit of energy released that is produced during combustion of methane is as much as 40 per cent lower than that produced by coal or about 20 per cent lower than oil. Due to this efficiency, any net dis- placement of higher greenhouse gas emitting fuels by meth- ane will result in a net mitigation of global greenhouse gas emissions (IEA 2011b). Natural gas gives off fewer pollutants when burned, including less particulate matter, sulphur di- oxide, and nitrogen oxides. In addition, it produces no waste products that require management, such as coal ash or nu- clear waste. Compared to conventional gas, gas originating from hydrates contains even fewer impurities, such as hydro- gen sulphide. This means that, of all natural gas sources, gas hydrates require the least refining to produce consumable natural gas (e.g. Collett et al, 2009). Although gas hydrate resources may prove to be vast, they are best considered as a potential option to ease the transi- tion to future sustainable energy systems. Ideally, gas hydrate development should not displace the necessary investment in renewable energy technologies that will form the basis of those future systems. If technologies to reduce greenhouse gas emissions associated with expanded gas utilization can be proven, it would be most beneficial to pursue parallel de- velopments in fugitive emission reduction during produc- tion and in carbon dioxide mitigation technologies. Production research and development studies suggest that gas hydrate deposits in both marine and permafrost settings can be produced using techniques and methods already em- ployed by the hydrocarbon industry worldwide (see Volume 2 Chapter 3). It is therefore reasonable to anticipate that the environmental considerations will also be similar. The prin-

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