Quote Originally Posted by blumpkin blownuts View Post
as measured in the ice cores, co2 concentrations from the last 400,000 years - that's the last five glacial cycles - have never been as high as they are now. they rarely pushed 350ppm, right now we're pushing 400

graph
http://en.wikipedia.org/wiki/File:Vostok_Petit_data.svg

great article & more graphs: http://www.daviesand.com/Choices/Pre...ning/New_Data/
according to the graph that you just posted thay're only at about 285 and have been higher no less than two times in the last 400,000 years