Global energy and the role of geosciences: A North American perspective

Abstract

The world contains abundant energy resources. The challenge is extracting and utilizing these resources affordably, in an environmentally responsible way, and in a dense enough form to be useful to humans. The link between energy, the environment, and the economy is unavoidable and involves the geosciences at its core. Carbon-based fuels such as wood, hay, and coal powered human society for millennia. Then, in the early twentieth century, petroleum in various refi ned forms came into use for lighting, heating, and early combustion engines. Today, fossil fuels—coal, petroleum products, and natural gas—represent an important 85% of the global energy mix, but they are not without challenges. Coal’s greatest challenges are environmental: the impact of surface mining; water contamination; discharge of airborne pollutants including sulfur, nitrogen, and mercury; and the emission of CO 2 . The emerging technologies of carbon capture and sequestration may offer the prospect of solving one of coal’s problems; large, stationary sources of CO 2 (such as coal-fi red power plants) are the most effi cient targets for carbon capture. However, capturing CO 2 is expensive. Oil and, to a much lesser degree, natural gas also produce CO 2 and other emissions when combusted. Oil and natural gas require drilling, entailing the associated environmental impacts of oil-fi eld operations; yet there remain considerable global oil and natural gas resources. The current frontiers for conventional oil and natural gas production include ultra-deep water, the Arctic, sediments deposited beneath major salt formations, and other extreme operational environments. As existing and new conventional oil and natural gas reserves decline, unconventional reservoirs—shale gas, coal bed natural gas, tight gas, shale oil, oil shale, oil sands, and perhaps eventually natural gas hydrates—will represent a growing part of the fossil-fuel mix.