Detection of Greenhouse Gases Using the Photoacoustic Spectroscopy

Abstract

Global warming is one of the main environmental problems of the XXI Century. It is generated by the intensive use of fossil fuels that leads to the so-called greenhouse effect (Meinshausen et al.,2009; Allen et al., 2009; Sthel et al., 2010; Hansen et al., 2008; Hansen & Makiko, 2004; Rosenzweig et al, 2008). It causes climate changes (Steffen et al., 2004; Solomon et al.,2009; Kevin et al., 2006; Kurz et al.,2008; Greene et al., 2009; Nathan P et al., 2008; Siddall et al., 2009; Sander et al, 2006; Emanuel, 2005; Peza & Simmonds, 2005; Janssen, 1998; Mann et al., 1998) and produces significant damages to the human society and biodiversity, such as the melting of the poles with the consequent increasing of oceans level, the intensity increasing of hurricanes, extreme events, changes in the rainfall patterns (floods, desertification), oceans acidification and biodiversity decreasing. Recently, the Intergovernmental Panel on Climate Change (IPCC) report (IPCC, 2007), published in February 2007, indicated based on meteorological studies, that the earth's global average temperature rose about 0.8oC in the last 150 years, mainly due to human activities. The global atmospheric concentrations of carbon dioxide(CO2), methane (CH4) and nitrous oxide (N2O)have risen considerably as a result of human activities since 1750. Increases in global carbon dioxide concentration are primarily due to the use of fossil fuels and changes in the use of the soil through practices such as deforestation, biomass burning and biomass decomposition. Practices such as logging, peat decomposition and burning and other techniques employed in the modern agriculture are resulting in an increased concentration of methane and nitrous oxide. While the global atmospheric concentration of carbon dioxide has increased from a pre-industrial value of about 280 ppmv to 379 ppmv in 2005, the global atmospheric concentration of methane (CH4) has increased from a pre-industrial value of about 715 ppbv to 1774 ppbv in 2005 and the global atmospheric concentration of nitrous oxide has risen from pre-industrial value of about 270 ppbv to 319 ppbv in 2005.