ABSTRACT
The concentrations of greenhouse gases (GHGs) in the atmosphere have reached unprecedentedly high levels and climate change is no longer a threat, but a reality. Atmospheric carbon dioxide (CO2) concentration has risen from 280ppm prior to the industrial revolution to 379ppm in 2005 (Forster et al, 2007). The rate of increase between 2000 and 2005 was 3.3 per cent per annum, attributed to expansion of economic activity, increased GHG intensity of economic activity, and declining strength of the oceanic and terrestrial C sinks (Canadell et al, 2007).
