In April, scientists in the United States found that the depletion of ozone gas in the world's atmosphere was at least three times more serious than had been predicted. This means that more ultraviolet rays are reaching the earth past a thinning "ozone shield", increasing cancer rates and harming human vision and crop productivity. For us in the Himalaya, the immediate question is what impact the decline in atmospheric ozone will have on high mountain regions, particularly on the health of people, livestock, crops and forests. Will the hills be more affected than the plains? Himal's Prakash Khanal found scientists agreed on the answer: yes. His report:
Trekkers on the mountain trails have known it for long. Up in the rarified atmosphere of the High Himalaya, the skin peels quicker and sunburn is instant because ultraviolet rays pierce through the thin atmosphere easily. Significant ozone depletion would mean that the higher altitudes would be much more affected by ultraviolet rays, which are sufficiently strong to break even biological molecules like the DNA, which controls heredity and cell control.
It is only in the past four years that the depletion of ozone began to be taken seriously, and studies so far have concentrated on confirming the general worldwide depletion and studying an "ozone hole" over Antartica. However, from what is known, there seems to be cause for concern in the Himalayan region because of the general thinning of the ozone shield worldwide and the strong possibility that a ozone hole similar to that over the South Pole hovers over the Himalaya.
"Naturally, increasing levels of ultraviolet radiation will affect the mountain people and crop production, the more so at higher altitudes," Sekhar Gurung, Associate Professor of Physics at Tribhuvan University. "If it is true that atmospheric ozone is being depleted, then, without doubt, the mountain environment is being affected. But more research needs to be done to determine the extent," says Suresh Chalisey, a meteorologist presently with the International Center for Integrated Mountain Development (ICIMOD).