"Go see the movie Tom. Carbon levels in the atmosphere are higher now than they have been in the last 600,000 years."

I don't have to waste your life watching a Gore movie to find out about CO2 levels. When humans were apelike creatures CO2 levels were about twice the current levels and Earth was much warmer:
http://www.clearlight.com/~mhieb/WVFossils/Carboniferous_climate.html

We living in a long period of warming in a much longer period of a cold period. And though there is not always a direct relationship, generally CO2 levels rise following warming trends. It is possible that if humans did not exist, that at this point in time, CO2 levels could be rising and average global temperature could rising.
Since the end of the Little Ice age [and there absolutely no evidence that human activity had anything to do with causing the Little Ice age to end] at most the global temperature has risen by about 1 C [150+ years ago].
In last 100 years global temperature has risen by about .6 C and since the high of 1998 has on average declined very slightly.
Since the time CO2 has been accurately measured, CO2 level have been increasing by more than 1 ppm per year. Which also mean btw that prior to 1958 we have less accurate "measurement" of CO2. The average rate since 1958 has been 1.4 ppm per year. It's unknown how much of this increase is due to human activity- less than 1/2 of the increase might a reasonable guess [probably less and very unlikely it's 90-100% of increase]. But again it's a guess, it is unknown how much of the increase is due to human activity. Of the .6 C increase in global temperature, it's extremely unlikely that all of the increase is due to human activity. And to say all the increase in temperature is due to CO2 levels increasing is even more implausible.