Here's a scientific mystery for you: where has all the ozone gone?
In 1985, researchers discovered a gaping hole in the layer of ozone-rich cloud over Antarctica. Ozone, a molecule of three oxygen atoms, may seem unassuming, but it absorbs light in the UV-B range, considerably reducing how much of it reaches the surface of the earth. When it comes to sunlight, this is the nasty stuff—skin cancer-causing, molecule-destroying, plant-killing wavelengths of ultraviolet. Ozone, happily, absorbs the lion's share before it starts frying our eyes.
One scientist, however, wasn't buying it. In 2001, Qing-Bin Lu, then at the University of Sherbrooke in Canada, published a paper linking ozone depletion to cosmic rays, the high-energy nuclei, electrons, and protons produced in galaxies far, far away. Examining ozone and cosmic-ray data from satellites, balloons, and ground stations for the years 1997—1992, Lu found a statistical correlation between cosmic ray intensity, related to the 11-year solar cycle, and global ozone levels. He also showed in the lab that when CFCs bound in a "cloud" (water vapor condensed on a metal rod at below-freezing temperatures) were bombarded with low-energy electrons, they were a million times more likely to let loose active chlorine. (Cosmic rays rarely make it through the atmosphere intact, but instead produce showers of other particles, such as low-energy electrons, when they collide with atmospheric molecules.)
In April 2009, Lu came out with even stronger support for his idea, or so it seemed. This time his study spanned the years 1980-2007. Again, he showed a correlation between cosmic ray intensity and mean global ozone levels, and between cosmic ray intensity and fluctuations in Antarctic ozone.
"These correlations mean that nearly 100 percent of the ozone loss over Antarcitca must be driven by cosmic rays," he told Physics World, implying that UV was just not the culprit here. But other climate experts were very skeptical of Lu's attempt to explain ozone depletion by a completely new mechanism. FULL ARTICLE
