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Page 1 | Page 2 | Page 3 | Page 4 Finite ReservoirIt took the Keeling Curve to prove false the explanation by early twentieth century scientists for where all the emissions of a new industrial era were going. As the age of the automobile ramped up, researchers at the time understood that human activities were producing extra carbon dioxide beyond the amount created by nature. They assumed, however, that the vast oceans would have the capacity to absorb that extra amount with little consequence to people. The curve showed that was far from the case. Beginning in March 1958 with an hourly measurement of CO2 taken at a National Weather Bureau station atop Hawaii's Mauna Loa, Charles David Keeling's measurements revealed a sharp increase in the concentration of carbon dioxide in the atmosphere. It has risen from roughly 315 parts per million (ppm) for that month to 383 ppm in the most recent measurement. The upward trajectory of the last century is nearly perpendicular to the flat line that existed in the centuries prior to the industrial age. As dramatized by former Vice President Al Gore in his film "An Inconvenient Truth," present-day levels are, in fact, a wild departure from anything seen in the last 480,000 years. Through several ice ages and interglacial periods, ice core records show that those concentrations have never risen above 300 ppm until now.  
But the measurement of rapid increase of CO2 in the atmosphere still doesn't account for all the CO2 that people have produced through fossil fuel burning, a quantity relatively easy to calculate from energy industry records from the past century. Where is the rest going? Scripps marine chemist Andrew Dickson has helped chip away at the answer from one angle. Since 1990, he has taken part in efforts to make ultraprecise measurements of concentrations of carbon levels in the oceans that show an upward trend consistent with uptake of carbon dioxide from the atmosphere. That uptake is part of a natural exchange of gases between the ocean and sky; the oceans are a carbon "sink" or repository, absorbing it through a direct mixing of gases that takes place through the actions of winds and waves at the surface and through the photosynthetic activity of phytoplankton in the surface ocean. But even though there was more carbon dioxide in the air and extra being taken up by the oceans, scientists have found these quantities in the two spheres still aren't sufficient to account for all that is produced by fossil fuel burning. Next page: Where do our emissions go? |
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