If the current CO2 increase is part of a natural cycle ...?

It just shows the lengths to which global warming deniers will go to in order to appear credible.

Jim z illustrates this point perfectly. 'Ignore your graph and look at mine', he asks. Of course, his graph stops 100+ years ago when atmospheric CO2 concentrations were still 280 ppm, over 100 ppm lower than today's!

There's your answer - it looks natural, as long as you don't look at the unnatural part.

That first 399,800 years looks natural. The last 200 doesn't.

Robert B is correct except about the Plutonium. Plutonium does not occur naturally.

Mr Jello and jim z are wrong to limit their attention to the Vostock ice core. The graph in my source is from many sources, including the Vostock core. And the sources overlap in dates, so that before the Vostock data ends the other data starts. And during the time periods where both data sets are available, they agree very closely on the concentration of CO2. I have no reason the believe they incorrectly Agree during the overlap period and incorrectly DISagree in the non-overlap periods. The most reasonable interpretation is that if they agree when both sets are available that they can be considered as equivalent sources and the later data from different sources is equally valid and correct and in agreement with the earlier data.

As stated on this site:

"I've combined the Vostok and Law Dome records into a single graph, along with one modern datapoint from 2007."

Sure, I'll play along with you if you can show me the scientific papers that support the notion that a direct CO2 measurement corresponds to a non-extrapolated ice core concentration measurement.

Ice cores are very good for demonstrating RELATIVE concentrations when comparing one core sample to another. You can't validly make a PRECISE comparison to non-core measurements for scientific purposes...

...but then this site does not have a scientific purpose.

Your little chart doesn't go back far enough.

Although it may be accurate, it is not any more accurate than the one I found, which shows no connection between CO2 levels and temperature changes over the billions of years of the history of life on the earth.

The second source has some interesting info about CO2 as well.

This point is only debatable in propaganda. This is one of those things that is understood as fact, we humans have caused the increase in [CO2] over the last 100+ years. Even skeptical scientists admit this much.This part of AGW is not open for real scientific debate. What is open for debate (some what) is what effect this increase is having.

Here is the real graph

http://upload.wikimedia.org/wikipedia/en/7/77/Vost...

It confirms what every decent geologist already knows, WE ARE COMING OUT OF A PERIOD OF GLACIATION! Those periods are clearly evident on that graph and 99 percent of it happened before humans were walking the earth. Jello is right. Humans have obviously added some of the CO2. The problem with your reasoning is that you assume CO2 is causing the warming. It is more likely the warming is causing the increased CO2.

The real Q is does Co2 deplete ozone? No. Does Co2 cause health problems? again no. Does Co2 cause global warming? maybe? maybe not? does the refrigerants we put into the atmosphere cause ozone depletion? yes..Is this a problem we can fix? yes. Go to CoolingEarth.org to learn more

The past data was taken from the Vostok Ice Core samples. The spike you identify as man made is taken from another location.

Do you 'cut and paste' data from different sources to get the graph you want?

Believers will go to any lengths to perpetuate this fraud.

Humans are natural. Making things and burning stuff are both natural behaviors for humans. Dying in large numbers due to war, famine, disease, floods, earthquakes and such is also natural. If you want to get technical uranium and plutonium are natural.