Imagine that one day our Ozone layer was disappeared. What will happen? How long can we survive without it? The Ozone layer is a region of Earth’s atmosphere that contains a high concentration of Ozone (O3). Ozone is a highly reactive gas composed of three oxygen atoms. It is found in the lower portion of Earth’s atmosphere. It absorbs 97 to 99 percent of the Sun’s ultraviolet rays. Direct exposure to UV rays can cause serious skin problems including sun burn, skin cancer, premature ageing of the skin, solar elastosis. It can also cause eye problems and can ruin our immune system.
The depletion of ozone layer was first observed by a Dutch chemist Paul crutzen. He described the Ozone depletion by demonstrating the reaction of nitrogen oxide with oxygen atoms which slowing the creation of Ozone (O3). Later in 1974, American chemists Mario Molina and F. Sherwood Rowland observed that chlorofluorocarbon (CFC) molecules emitted by man-made machines like refrigerators, air conditioners and airplanes could be the major source of chlorine in the atmosphere. One chlorine atom can destroy 100,000 ozone molecules.
Not all chlorine molecules contribute to ozone layer depletion; chlorine from swimming pool, sea salt, industrial plants, and volcanoes does not reach the stratosphere. The ozone hole in Antarctica is one of the largest and deepest depletion which was discovered by the British scientists. This became worldwide headlines after that. According to NASA scientist Paul Newman, if this depletion continues in this rate our ozone layer can be likely disappeared in 2065. If that happens UV rays from sun directly reach earth and cause severe health issues, Humans can last 3 months and plants may die in 2 weeks because of heavy UV radiation. Thus Earth will become inhabitable.
Fortunately in 1987, Montreal protocol was made that bans chlorofluorocarbon and other chemicals that cause ozone depletion. Surprisingly it works, researches made in 2018 tells that the ozone layer is repairing itself at a rate of 1% to 3% per decade since 2000. Still it will take at least 50 years for complete recovery. The greenhouse effect allows the short wave radiation of sunlight to pass through the atmosphere to earth’s surface but makes it difficult for heat in the form of long wave radiation to escape. This effect blankets the earth and keeps our planet at a reasonable temperature to support life. Earth radiated energy, of which about 90 percent is absorbed by atmospheric gases like water vapor, carbon dioxide, ozone, methane, nitrous oxide, and others. Absorbed energy is radiated back to the surface and warms earth’s lower atmosphere.
The gases have come to be called greenhouse gases because they hold in light and heat, just as a greenhouse does for the sake of the plants inside. Greenhouse gases are essential to life, not only at an appropriate balance point. These gases increased during the 20th century due to industrial activity and fossil fuel emissions. For example, the concentration of carbon dioxide I the atmosphere have recently been growing by about 1.4 percent annually. This increase in greenhouse gases is one of the contributors to be observed patterns of global warming. On September 16th world ozone day, we can celebrate our success. But we must all push to keep hold of these gains, in particular by remaining vigilant and tackling any illegal sources of ozone depleting substances as they arise, says UN ozone-secretariat. So without the Montreal protocol, life on earth could be a question mark, so keep working hard. “OZONE FOR LIFE”.