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A false-color view of total ozone over the Antarctic pole is seen in this NASA handout image released October 24, 2012. The purple and blue colors are where there is the least ozone, and the yellows and reds are where there is more ozone. The average area covered by the Antarctic ozone hole this year was the second smallest in the last 20 years, according to data from NASA and National Oceanic and Atmospheric Administration (NOAA) satellites. Scientists attribute the change to warmer temperatures in the Antarctic lower stratosphere. The ozone hole reached its maximum size September 22, covering 8.2 million square miles (21.2 million square kilometers), or the area of the United States, Canada and Mexico combined. REUTERS/NASA/Handout

On Feb 16, environmental scientists from the University of Leeds in England said that they were concerned about the rising levels of ozone-destroying gases that are chewing off the ozone layer, which is the most protective layer for the Earth. They felt that the Earth was threatened because of it.

The study by the scientists was published in Nature Geoscience, a multi-disciplinary journal regarding Earth sciences. The study made use of raw data provided by the National Oceanic and Atmospheric Administration in the US, an agency that looked into the condition of the atmosphere and oceans.

The researchers said that two computer models looked into the impact of the "very short-lived substances" (VSLS) substances mostly of natural origin produced by phytoplankton in the ocean and seaweeds, contributing to stratospheric ozone loss and breaks down in less than six months. It was found that the damage that VSLS did to the ozone layer was likely to increase with the increase of emissions of chlorine that was man-made.

The lead investigator of the study and a research fellow from the University of Leeds, Ryan Hossaini, said that their model simulations indicated that the VSLS accounted for a remarkable portion of the ozone loss in the stratosphere. He explained that the ozone hole formed in the Antarctic region and that was where the decrease of ozone was the most dramatic. He added that the VSLS accounted for approximately 12.5 percent of the total ozone loss in the Antarctic region.

Hossaini explained that dichloromethane, a chemical used in the manufacturing of substitutes for the gases depleting the ozone layer, was one of the most abundant of the man-made VSLS that they knew of. In the 1987, the Montreal Protocol of the United Nation outlawed the chemical.

According to Hossaini, when the impact of dichloromethane was compared to that of chloroflourocarbons(CFC), which is produced as a derivative of methane, propane and ethane, the impact was small. He added that the computer models suggested that dichloromethane reduced the ozone layer by less than 1 percent.

Hossaini went on to say that their study showed that in recent years, the atmospheric concentration of the chemical had drastically increased. He added that in a few of the locations, since the 90s, the atmospheric concentration of dichloromethane had doubled.

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