Historical carbon dioxide concentrations:
http://ff.org/centers/csspp/library/...18/dioxide.htm
We currently have an Earth History low.
We continue to suffer from an Importance Complex even though we have only been recording our history for a few thousand years out of the billions of Earth age and we confound it by not realizing recorded temperatures only started after the invention of the thermometer about 150 years ago.
And we further contaminate the GW issue by using false land based temperature measurements (UHI effect) while ignoring satellite measurements showing no discernible warming over the past 20 years (wrote this earlier and repeat for emphasis).
So who is lying? The Earth history?
And to repeat it is not that the Earth is not warming. It is that it is not us as the cause. It is the Solar cycle that is the cause and that directly influences carbon dioxide levels.
Here is a link to the topic of Solar activity and Earth climate:
http://www.sciencedaily.com/releases...0607073439.htm
As noted there it is still a matter of more research.
And this looks at both sides of the issue of cause:
http://www.global-warming-and-the-climate.com/
Check out the link through titled: increased levels of greenhouse gases near page bottom.