Carbon Capture and Storage: Science and Technology Focus for Mitigation of Climate Change

Global warming is attributed to increasing greenhouse gas emissions and mounting concentrations of carbon dioxide and other gases in the atmosphere. Since the middle of the 19th century, increasing worldwide anthropogenic activity is said to have given rise to a steady increase of carbon dioxide in the atmosphere. This is corroborated by direct measurement of CO2 concentrations at Mauna Loa Laboratory in Hawaii (USA). The CO2, present in the atmosphere as a trace gas, has an average atmospheric concentration of 280 ppmv. In 1958 the observed concentration was 315 ppmv, which suggested an increase of about 0.5 ppmv per year in the initial half of the 20th century. In 2005 the measured concentration of CO2 was 374 ppmv, suggesting an increase of about 1 ppmv per year in the latter part of the 20th century. The rising concentration of CO2 is ascribed mainly to the use of fossil fuels—coal, oil and gas—for energy production and consumption. According to the International Energy Outlook 2007, world energy consumption is expected to grow from 442 quadrillion Btu (~ 750 billion boe) in 2004 to 702 quadrillion Btu (~ 1200 bboe) in 2030. In view of coal meeting 40% of world wide electricity needs and its high contribution to greenhouse gas emissions, it is imperative that options for reducing emissions from coal use be explored.