Question

How are CFC harmful for the environment and living beings? Mention any two human activities which would lead to an increase in the carbon dioxide content of air.

Answer 1

Answer:

1-use of A.C 2- due to green house effect

Answer 2

1. human activities especially burning fossil fuels are leading to increased levels of carbon dioxide and other greenhouse gases in the atmosphere.
2. The "smoking gun" that shows clearly that human activities are responsible for recent increases in carbon dioxide in the atmosphere.
3. Deforestation: Trees are potent organisms for absorbing and removing CO2 emissions from the air. Cutting them down stops that process. Although deforestation is a minor source of increased CO2 in the U.S., loss of forestlands account for 20 percent of global CO2 emissions. Burning trees for fuel and natural decomposition of forest material also release CO2
4. Building: Industrial manufacturing emits lots of CO2, but it only accounts for 2 percent of U.S. emissions. Iron and steel manufacturing and cement production are the biggest offenders. These industries consume monumental quantities of heat energy to convert raw materials into construction products
5. vehicle such as car cars emit smoke may lead to carbon dioxide gases.

    The following are How CFC harmful for the environment and living                  beings.

Chloroflorocarbon (CFC) molecules are made up of chlorine, fluorine, and carbon. They are mainly released from refrigerators, air conditioning system, sprays and from emission from jets.

When released into the air, CFCs rise to the stratosphere. CFCs are subject to higher levels of ultraviolet radiation that decompose them and release atomic chlorine. Atomic Chlorine reacts with Ozone and gives out oxygen as follows:

Cl+O3→ClO+O2

In the above reaction, atomic Chlorine (Cl) gets removed once it has converted an ozone molecule to Oxygen molecule but then it is regenerated through reaction of Chlorine Monoxide (CIO) with oxygen atom (O) as follows:

ClO + O→Cl + O2

The net reaction in above two sets is as follows:

O3+O→2O2

The net result of the two reactions is the depletion of ozone which protects the earth from the harmful ultraviolet rays of the sun. Thus by depleting ozone layer CFCs cause Global Warming which further affects the whole environment.

Effects on human:

Potential risks include eye diseases, skin cancer and infectious diseases.

UV radiation may damage the cornea and lens of the eye.