Climate change is, first and foremost, a consequence of the addition of carbon dioxide into the atmosphere. We emit carbon dioxide, through burning fossil fuels or forests, and some of that carbon stays in the atmosphere, intensifying the heat-trapping greenhouse effect and warming the climate. What kind of global warming we’ll see in the future will largely be due to how much carbon dioxide—and to a lesser extent, other greenhouse gases like methane—we add to the atmosphere. And to fully understand the future, we need to understand the present and the past, and track the concentration of CO2 in the Earth’s atmosphere.
The fact that we can and have been tracking that very important number is due largely to the efforts of the geochemist Charles David Keeling. As a postdoctoral fellow at the California Institute of Technology in the 1950s, Keeling developed the first instrument that could accurately measure the CO2 levels in the entire atmosphere through sampling. When he got to the Scripps Institution of Oceanography a few years later, Keeling began taking regularly CO2 measurements at the Mauna Loa Observatory in Hawaii. Keeling discovered that atmospheric CO2 underwent a seasonal cycle, as plants bloomed and decayed in the Northern Hemisphere, and more importantly, that CO2 was rising fast. In 1958, CO2 levels recorded at Mauna Loa were about 316 parts per million (ppm). By 2005, when Keeling died—and his son, Ralph Keeling, took up the project—CO2 levels were just under 380 ppm. Plotted on a graph, the readings over time curve upwards sharply as humans added more and more CO2 to the atmosphere—which is why the readings came to be known as the Keeling Curve.
Read more: http://science.time.com/2013/05/02/greenhouse-effect-co2-concentrations-set-to-hit-record-high/#ixzz2SCf4u4pO
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