Questioning the Mauna Loa CO2 Data

The observational data of atmospheric CO2 concentration obtained from the observatory located in Mauna Loa, Hawaii, is tauted as most complete and most authoric data evidence that the global CO2 concentration goes up over the years, therefore provides a support for the Global Warming Theory.

I seriously challenge the validity of that piece of data. But first I am not questioning the hardwork of the researchers or their honesty in recordingh the data faithfully. I do believe their instruments recorded the correct readings. BUT, the interpretation of the data is very questionable.

If you look at the graph, you see a nice general trend that the CO2 concentration is going up, but you also notice a strong seasonable oscillation.

That seasonal oscillation is rather suspicious. The reseachers claim, because of the geological location of the observatory, they are measuring a CO2 concentration FREE from any bias caused by any local effects. Since the global atmosphere gets pretty good mixing at a time scale much shorter than a year, they are measuring the true global average of the CO2 concentration.

Is that so? Are they truely measuring the global average? How can the seasonable oscillation be explained? If it is a true global average, there should be no seasonal oscillation. We know, globally, when the northern hemisphere is winter time, it is summer time in the southern hemisphere. So it should all average out and there should never be such a dramatic seasonable modulation in the curve.

The seasonal modulations clearly must have a local explanation. Are they related to the seasonable plantation and biomass growth? Hardly! The geographical location of Mauna Loa has a pretty low lattitude, and the weather is oceanic, meaning it is virtually the same comfortable temperature good for plantation growth year around. There should not be a very strong seasonal effect. Also, if you look at the Data List, you notice that the CO2 peaks around May and reaches the lowest point around October. Why? You would expect that in late spring, due to strong plantation growth and photo synthesis, lots of CO2 are absorbed and so you should see the lowest concentration of CO2, not highest.

The answer may lie in the tourism. You see more tourists in the spring time leading to May, so all the extra automobile activities releases more CO2 into the local atmosphere. And in the fall and winter, much less tourists. And the gradual build up of CO2 over the years may not be a global effect, but simply a local effect that more and more visitors vist Hawaii each year.

And that certainly bring a question to the legitimacy of regarding the Mauna Loa reading as that reflecting the global trend. You need data from a different location, one that is far away from local human influence, to draw conclusions. Unfortunately I do not see any data other than the Mauna Loa one.

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