Spores record changes in ozone concentration

From Calgary, Alberta, at the Earth Systems Processes 2 meeting of the Geological Society of America and the Geological Association of Canada

The chemistry of plant spores on a frigid Antarctic island chronicles decreasing concentrations of ozone over the region in recent decades. Scientists may take advantage of that trend to learn about ancient extinctions.

At far-southern latitudes, the concentration of stratospheric ozone—an atmospheric constituent that provides protection against the sun’s ultraviolet radiation—has dropped about 14 percent in the past 4 decades, says Barry Lomax of the University of Sheffield in England.