The concern about global warming has increased dramatically. The

Intergovernmental Panel on Climate Change (IPCC) (Lemke et al., 2007) has reported the current knowledge on its implications and

potential risks. For instance, even modest change in ice sheet bal-

ance could strongly affect future sea level and freshwater flux to

the oceans. Among the reported observations is that the annual

mean ice extent in the Arctic Sea has decreased 2.7% per decade in

the last 30 years and the minimum Arctic Sea ice extent (summer)

has decreased even faster (7.4% per decade). The potential conse-

quences vary from fauna change and extinction in the arctic region

to floods and further temperature balance worldwide. The increase

of greenhouse gas emissions is accepted as the main cause of this

situation and CO2 is the most important anthropogenic greenhouse

gas. The analysis of ice cores led to the conclusion that the global

atmospheric concentration of CO2 in 2005 (379 ppm) had already

exceeded by far the natural range over the last 650,000 years (180-

300 ppm) and is continuously increasing with amuch higher growth