Abstract
Climate change issues are discussed widely around the world. Many scientists (Treut et al., 2007) relate global warming and its consequences to human activities and not to natural fluctuations. The reasoning of this approach is the timescale of climate change. Recent warming of the Earth is considered to be abrupt compared to the timescale usually accompanied with natural climate change episodes. Earth’s natural climate changes happen gradually in a long period of time (tens of thousands to millions of years), but we are witnessing an abrupt change over the past 200 years. The industrial revolution with fossil fuels as its main source of energy is setting a steady emission increase of carbon dioxide and other greenhouse gases which trap heat causing an increase of temperature in the lower atmosphere.