12th GEOSEA 2012, Bangkok, Thailand
Mega Geological Hazards and Changing Earth: Climate Change
David A. C. Manning School of Civil Engineering & Geosciences, Newcastle University,
Newcastle upon Tyne, UK, NE1 7RU E-mail : david.manning@ncl.ac.uk
Whether we like it or not, there is little doubt that human activity has increased atmospheric CO2, and we now face the consequences of this for the Earth’s climate. Human perturbation of the global climate system is believed to have started with the dawn of agriculture and the cultivation of rice (Ruddiman et al., 2011). If the climate had developed as expected from previous patterns, glacial conditions would have resumed at some stage during the last 10000 years, and human activities seem to have prevented this from happening. Our use of fossil fuels, especially since the start of the Industrial Revolution, has accelerated the rate of increase of atmospheric CO2. But fossil fuels are not the only source of greenhouse gases. Other emissions of greenhouse gases include nitrogen oxides and ammonium from agriculture, and these also contribute to global warming. With current trends to increased use of coal for electricity generation to support improved standards of living and to meet the needs of growing economies and populations, there seems to be little prospect of humanity reducing CO2 emissions. Although much needs to be done and can be done to provide alternative carbon neutral energy, for example from geothermal sources, there is an opportunity for the geologist to use his/her skills to develop affordable techniques that remove CO2 from the atmosphere. One such technique includes Carbon Capture and Storage (CCS), exploiting the infrastructure of petroleum production so that depleted gas and oil fields are recharged with CO2 captured from the exhaust gases of power generating plants. The financial and energy costs are high. Carbonation of silicate minerals is an alternative technique. It is known that minerals such as olivine (Mg2SiO4) will react with CO2 to give a carbonate mineral –magnesite – and Ca silicates react to give calcite. This process can, in principle, be integrated with a CCS activity, in areas where Ca and Mg silicate rocks occur in the subsurface, but is still expensive. Additionally, the process also occurs in soils. Mimicking the natural formation of pedogenic carbonates, both natural and artificial Ca and Mg silicates soils can be added to soils, within which comparatively inexpensive natural weathering processes form Ca and Mg carbonates. These are effectively permanent sinks for CO2. Ruddiman, W.F., Kutzbach J.E. and Vavrus, S.J. 2011.Can natural or anthropogenic explanations of late-Holocene CO2 and CH4 increases be falsified?The Holocene 21, 865-879. BOOK OF ABSTRACTS
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