OH and i didn't even mention the changes in the earth's axial tilt (Milankovitch cycles) that occasionally occur in our planet, and that Scientists say have been a major factor in the glacial periods that may have appeared in the graph contained in post 196.
For more information on this: http://www.scotese.com/climate.htm
Now look at this graph and note how solar output is decreasingly having an effect in global warming, suggesting that man-caused greenhouse gases such as co2 emissions are the problem:
How does this suggest that man created this? The first thing I notice in your graph was during WWII when man was at our highest level of pollution the temperature went down. All this graph shows me is there are other forces acting on the earth to create the change in temperature. We know it isnt CO2 because we can mathematically calculate the amount of temperature gain.
Should we figure out what it is? YES Should we point fingers before we figure that out? You tell me.
I would first suggest we look at other planets in the solar system to see what they might be doing. We do know that Mars and Pluto are warming up in the past few years.
It is interesting to note on cycles we found tropical plants in Antarctica.