Scientists puzzled by accelerating CO2 buildup in atmosphere

A sharp acceleration in the rate of increase of carbon dioxide in the atmosphere has climate scientists puzzled and sounding a bit nervous. Mauna Loa Observatory, perched on a mountain in Hawaii, has been taking atmospheric CO2 measurements for almost 50 years. In recent decades, the rate of increase has averaged about 1.5 parts per million (ppm) a year, but in 2002 and 2003, the rate jumped up to 2.08 ppm and 2.54 ppm respectively, an unprecedented acceleration. Climate researchers acknowledge that it could be an anomaly — perhaps due to increased forest fires in the Northern Hemisphere or something of the sort. But if the acceleration continues, warns climate-research old-timer Charles Keeling, it could herald “the beginning of a natural process unprecedented in the record” — the so-called “runaway greenhouse effect,” wherein the world’s natural carbon sinks lose their ability to absorb CO2 and a self-reinforcing cycle of rapid warming begins. Yikes.