The manner in which human activities are causing the depletion in the Ozone and increase in the levels of carbon dioxide and other harmful gases,our planet will soon become uninhabitable. What immediate steps do you suggest we taken by our friends and family to put a stop to the situation immediately.
Answers
Answer:
the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product.
What is the ozone layer and how was it damaged?
The ozone layer sits in the stratosphere between 15 km and 30 km above the earth. It absorbs most of the sun's ultraviolet radiation (UV-B), limiting the amount of this radiation that reaches the surface of the Earth. Because this radiation causes skin cancer and cataracts, the ozone layer plays an important role in protecting human health. It also prevents radiation damage to plants, animals, and materials.
In the 1970s, scientists noticed that the ozone layer was thinning. Researchers found evidence that linked the depletion of the ozone layer to the presence of chlorofluorocarbons (CFCs) and other halogen-source gases in the stratosphere. Ozone-depleting substances (ODS) are synthetic chemicals, which were used around the world in a wide range of industrial and consumer applications. The main uses of these substances were in refrigeration and air conditioning equipment and in fire extinguishers. Other important uses included aerosol propellants, solvents and blowing agents for insulation foams.
Illustration of the ozone depletion (blue colours) in the South hemisphere in 2006. Source: National Aeronautics and Space Administration (NASA) - Goddard Space Flight Center
Ozone depletion (blue colours) in the South hemisphere in 2006.
Source: National Aeronautics and Space Administration (NASA) - Goddard Space Flight Center
International action has been effective in protecting the ozone layer
To halt the depletion of the ozone layer, countries around the world agreed to stop using ozone-depleting substances. This agreement was formalised in the Vienna Convention for the Protection of the Ozone Layer in 1985 and the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987. In 2009, the Vienna Convention and the Montreal Protocol became the first treaties in the history of the United Nations to achieve universal ratification. Substances covered by the protocol are referred to as 'controlled substances'. The main substances include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, carbon tetrachloride, methyl chloroform and methyl bromide. The damage to the ozone layer caused by each of these substances is expressed as their ozone depletion potential (ODP).
Figure 1: Consumption of controlled ozone-depleting substances
2007, governments made an additional commitment, agreeing to freeze production of HCFCs in developing countries by 2013 and to bring forward the final phase-out date of these chemicals to 2030.
These international agreements helped to greatly reduce the worldwide use of ozone-depleting substances in Europe and around the World (Figure 1). Scientific monitoring shows signs that the ozone layer is starting to recover. Full recovery is not expected to occur before the middle of the 21st century.
Protecting the ozone layer also protects the climate
The reduction in ozone-depleting substances has also had a beneficial side-effect. Ozone-depleting substances are also very potent greenhouse gases, contributing to the phenomenon as other substances widely known to have a greenhouse effect like carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Therefore, by reducing emissions of ozone-depleting substances, the Montreal Protocol has protected both the ozone layer and the climate at the same time.
The magnitude of this benefit is substantial. The reduction in ODS emissions expected as a result of compliance with the Montreal Protocol has been estimated globally at 10-12 giga-tonnes of CO2-equivalent between 1985 and 2010 (Velders et al. 2007). In contrast, the reduction target of greenhouse gas emissions under the Kyoto Protocol (assuming full compliance by all developed countries) is estimated at 1-2 giga-tonnes of CO2-equivalent on average per year between 2008 and 2012, compared to base-year emissions. The phasing out of climate-changing ODS under the Montreal Protocol has therefore avoided greenhouse gas emissions by an amount 5-6 times larger than the target of the Kyoto Protocol for 2008-2012.