Scientists, and not weathermen, have spotted dark clouds over Kolkata. Known as Polar Stratospheric Clouds, these formations comprising mainly of gases and fumes from automobiles, reside at a much higher altitude than ordinary rain-bearing clouds.
But why should such findings ring alarm bells among the city’s population? SK Chakraborty, head of the Indian Centre for Space Physics in Kolkata, and one who led a team of scientists to report the findings, told HT: “These clouds are formed from gases, especially chlorine, which react with ozone molecules and destroy them. The results are disastrous — depletion of the ozone layer located in the stratosphere.” And, once the ozone layer gets damaged, harmful ultra-violet (UV) rays from the sun will reach the earth. UV rays not only can cause cancer in human beings, but can also trigger gene mutations, responsible for other life-threatening diseases. UV rays have disastrous effects on plants and animals, too, thereby disrupting the food chain and can even play havoc with the climate.
“These clouds are usually found above the polar regions, particularly Antarctica. But this is the first time that such clouds have been spotted over the city,” Chakraborty said.
The findings have been documented in the European Rocket and Balloon Programmes and Related Research journal published by the European Space Agency. NASA has already shown interest in the findings and has sent a questionnaire to Chakraborty and his team.