The Earth s temperature has risen 0.76℃ (degree) during last 100 years which Implies a sudden rise, compare with the 4℃ (degrees) rise through out the past 20,000 years. If the volume of GHG (Greenhouse Gas) emission continues at the current level, the average temperature of the Earth will rise by 1℃ (degree) by 2030 with the further implication that the temperature of Earth will rise by 2~5℃ (degrees) every 100 years. Therefore, as we are aware that the temperature of the glacial epoch was 8~9℃ (degrees) lower than the present time, we can easily predict that the above temperature rises can be potentially disastrous for human life. Every country in the world recognizes theseriousness of the current climate change and adopted a convention on climate change in June 1992 in Rio. The COP1 was held in March 1995 in Berlin and the COP3 in Dec. 1997 in Kyotowhere the target (2008-2012) was determined andthe advanced nations reduction target (5.2%, average)was also agreed at this conference. Korea participated in the GHG reduction plan which required the world’s nations to ratify the Kyoto Protocol.Ratification of the Kyotoprotocol and the follow-up requirement to introduce an international emissions trading scheme will require severe reductions in GHGs and considerable economic consequences. USAare still refusing to fully ratify the treaty as the emission reductions could severely damage the economies of these countries. In order to estimate the exact CO₂ emission, this study statistically analyzed CO₂ emission of each country based on the following variables : level of economic power and scientific development, the industrial system, productivity and energy efficiency.