POTENTIAL IMPACT ON CLIMATE OF THE EXPLOITATION OF METHANEHYDRATE DEPOSITS OFFSHORE

Abstract

Considerable attention has focussed on methane hydrates as a potential energy resource but much less on the potential environmental problems of exploiting these deposits. In fact, methane hydrate deposits represent a dynamic system formed as a result of the continuous migration of methane gas along fracture systems. Any exploitation of methane hydrates offshore will perforce take place in these unstable systems and could lead to the large-scale release of CH4 under unfavourable circumstances. However, most of this CH4 would be oxidized to CO2 within the water column under steady-state conditions. Only under exceptional circumstances would large-scale release of CH4 into the atmosphere take place. The impact of exploiting these deposits offshore on global climate may therefore be limited provided serious efforts are made to minimize environmental impacts. At present, prospects for the commercial exploitation of methane hydrates are in their infancy. Considerable ingenuity will be required to satisfy the requirements of safe operating conditions, mitigation of environmental hazards and commercial viability. The need to exercise caution before attempting to exploit these deposits is emphasized.