Modern global warming and its uncertainties based on the relationship between CO₂ concentration and temperature from geological records

Global warming has become a great focus for international community in recent years.However,did it really happen? What factors have driven and are still driving it? How to identify the roles of natural and man-made process? Scientists have different opinions on these questions.IPCC asserted that modern global warming was caused by the increase of CO₂ concentration mainly due to human activities.However,many scientists did not agree with this statement.In order to sort out this problem,we investigated the published data concerning the relations of atmospheric CO₂ concentration and temperature during various geological periods.The results show,both from the geological time scale and from the modern short time scale,no convincing relationship between CO2 concentration and temperature can prove that the increasing temperature nowadays is caused by the increasing CO₂ concentration.This indicates the great uncertainty about driving factors on temperature increasing,nor can we determine the main reason of global warming by now.7 page(s