Question

Mr. Chopra wanted to buy a new refrigerator and new air conditioner in place of old ones which were purchased 10 years ago. When he went to the market to buy these items, his son Aniket, a student of 10th standard also went along. Before buying a new refrigerator and an air conditioner Aniket asked various details from the shopkeeper and made sure that these items work with new eco-friendly refrigerant. Mr. Chopra was puzzled by this discussion. When they reached home Aniket explained everything to his father. His father was happy at Aniket's choice. (a) What do you think were the refrigerants used in old refrigerator and air-conditioner? (b) Name the new refrigerant being used in the air conditioner and refrigerators. Why is it not harmful to the environment?

Answer 1

I've written it point wise, so it'll be easy for everyone to understand...--

In 1987, nearly 200 nations agreed to phase out the use of chlorofluorocarbons, a coolant used in refrigerators and air conditioners, with the adoption of the Montreal Protocol.

The treaty was agreed upon after scientists confirmed the link between CFCs and the depletion of the ozone layer which protects the Earth’s surface from the sun’s harmful ultraviolet radiation and two years after the discovery of an ozone hole in the stratosphere above Antarctica.

The treaty has successfully repaired the ozone layer.

Recent climate projections indicate that the ozone layer on track to return to 1980 levels between 2050 and 2070.

According to the U.N. Environment Program, the treaty will have prevented 2 million cases of skin cancer annually by 2030, averted damage to human eyes and immune systems, and protected wildlife and agriculture.

The down side is.......
While the Montreal Protocol has repaired the ozone layer, a grave downside of the treaty has emerged.

CFCs were replaced by hydrofluorocarbons (HFCs), compounds that may not harm the ozone layer, but have proven to be powerful greenhouse gases with remarkable heat-trapping capability.

Since 1990, according to the EPA, there has a 258 percent increase in HFC emissions.