Some of this and the lag time in the graph is explained at: <a href="http://www.newscientist.com/article/dn11659-climate-myths-ice-cores-show-co2-increases-lag-behind-temperature-rises-disproving-the-link-to-global-warming.html?full=true">http://www.newscientist.com/article/dn11659-climate-myths-ice-cores-show-co2-increases-lag-behind-temperature-rises-disproving-the-link-to-global-warming.html?full=true</a> The earth would be much colder if CO2 and other greenhouse gases were not in the atmosphere. (take a look at what CO2 in the atmosphere has done for Venus at http://www.un