FROZEN HEAT | Volume 2

global perspective, understanding the triggers and implica- tions of methane release from destabilized gas hydrates is a critical knowledge gap that needs to be addressed. While environmental considerations related to gas hydrates in nature remain an understudied topic, the environmental issues related to gas hydrate production would, in many ways, be quite different. Perhaps the primary difference relates to issues of scale. For example, when considering gas hydrates in nature, first-level issues relate to the vast amounts of gas hydrate distributed widely around Earth, but in relatively low concentrations. In comparison, commercial exploitation of gas hydrates would be limited to localized, concentrated de- posits. The surface area of a typical field development would be less than 10 square kilometres and production would likely last less than 25 years. However, the issue of how local- scale exploitation of gas hydrates might interact with natu- rally occurring processes would have to be addressed. A unique environmental challenge facing gas production from oceanic hydrates would be the disposal of the dissociation-origi- nating water (Moridis and Reagan 2007a, b). This water, which would be anoxic, relatively low in salinity, and possibly quite cold, could have a considerable adverse effect on chemosynthet- ic communities on the ocean floor if not released higher in the water column. Another important challenge relates to the burial depth of many marine gas hydrate deposits. Geohazards like slope de-stabilization could by induced by extraction activities. Policy The policies that shape the future global energy system will depend on how human societies and decision-makers prioritize a range of objectives, including climate change mitigation, energy security, air and water quality, and hu- man health. The issues that will have to be addressed extend beyond national borders and beyond short-term time scales. They include, but are not limited to, the following: • Environmental issues and safeguards; • Socio-economic issues and opportunities; and • Policy development at the national, multinational, and international levels.

Photo: Geological Survey of Canada

Environmental Methane is a fossil fuel that contributes to greenhouse gases when burned. In addition, methane is, itself, a greenhouse gas. The presence of methane in the atmosphere was an important factor in creating – over geologic timescales – the global atmos- pheric and temperature conditions that have allowed humans to flourish. In recent times, however, the scientific consensus is that both anthropogenic methane and natural methane released as a result of human activities have helped induce global warm- ing (IPCC, 2007) and are a concern as the world struggles to mitigate and adapt to climate change. Although less common than carbon dioxide in the atmosphere (Blasing 2011), methane is a particularly potent greenhouse gas (Lacies et al. 1981; Hans- en et al. 1988), and relatively small fluctuations in atmospheric methane concentrations can have a large greenhouse impact. Methane release from naturally dissociating gas hydrates is a topic of interest to those studying global climate change (Reagan and Moridis 2008, 2009). Although research on the subject has already been reported (Elliott et al. 2011; Bhat- tacharyya et al. 2012), it is currently included in only a few cli- mate predictions, partly because the magnitude and timing of geologic emissions are poorly understood and therefore difficult to build into regional-scale models. Nevertheless, dissociation of gas hydrate deposits could, in the future, am- plify warming, increase ocean acidification, and exacerbate oxygen loss (Zachos et al. 2005; Biastoch et al. 2011). From a

One argument that is advanced in support of developing natu- ral gas hydrates as an energy source is that they are relatively

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