I look at the temperature chart derived from Godard Institute for Space Studies. It shows me one century of global warming, an upward zigzag. I read that 75 percent of global warming effects will persist until five hundred years from now. I try to imagine what life was like in 1513. Thirty thousand years from now, ocean currents will have absorbed more of the carbon compounds, but 25 percent will still hang around in the atmosphere. The half-life of plutonium-239 is 24,100 years. These periods are as long as all of visible human history thus far. The paintings in the Chauvet Cave in France date back thirty thousand years. But 7 percent of global warming effects will still be occurring one hundred thousand years from now as igneous rocks slowly absorb the last of the greenhouse gases.
