Thursday, September 14, 2006

The evidence is in the bubbles

Ice cores drilled in the Antarctic tell a revealing tale of the history of carbon dioxide in Earth's atmosphere. As the ice accumulates, it traps air bubbles which capture a sample of the atmosphere at the time of deposition. A core has been drilled to depths that represent an accumulation history of 800,000 years. Analysis of the entrapped air shows atmospheric CO2 varying between 180 to 300 ppm of air as climate changed. But in the last 200 years it has accelerated to 380 ppm, off the scale so to speak. Furthermore, carbon isotope measurements suggest the additional CO2 is coming from fossil sources, i.e. from human activity.

Like the ice, the evidence of our assault on our planet's climate steadily accumulates. Unfortunately, our wisdom doesn't.

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