Tag: global environmental change

• As individuals, we can help by taking action to reduce our personal carbon emissions.
•  But to fully address the threat of global warming, we must demand action and support and implement a comprehensive set of climate solutions:
•  Expand the use of renewable energy and transform our energy system to one that is cleaner and less dependent on coal and other fossil fuels.
•  Increase vehicle fuel efficiency and support other solutions Place limits on the amount of carbon that polluters are allowed to emit. 
• Build a clean energy economy by investing in efficient energy technologies, industries, and approaches. 
• Reduce tropical deforestation and its associated global warming emissions.
• Hence, Increasing the use of air conditioners, refrigeration unit and production of plastic foams and propellants in aerosol spray cans is not a correct approach to reduce global warming. 
• So, the correct answer is 'Increasing the use of air conditioners, refrigeration unit and production of plastic foams and propellants in aerosol spray cans'.

Global warming is caused by increased concentration of greenhouse gases (carbon dioxide is one of the greenhouse gas) in the atmosphere. Increased organic matter in lakes causes eutrophication. Ozone depletion is mainly related to the use of CFC-based products. Acid rain is the result of increased sulphur and nitrogen oxide levels in the atmosphere. Increased use of pesticides causing the death of predators will cause accumulation of nonbiodegradable compounds in the food chain. Thus, the correct answer is option A. 

The Ultra-violet radiations are the potent mutagens as they are capable of distorting the structure of the DNA. The UV radiations cause the adjacent pyrimidines residues (thymine and cytosine) to form hydrogen bonds with each other rather than the corresponding purine residues. Generally, the thymine dimers are seen as immediate effects of the UV radiations. Due to this type of mutation, the errors in replication of DNA are frequent to observe. The breaking of hydrogen bonds between the two complementary DNA strands occurs due to increase in temperature. This is not considered as a mutation because when normal conditions arrive the hydrogen bonds can be formed again.

Global warming refers to the overall increase in the tropospheric temperature reflected on the earth's surface. Developing substitutes for chloroform will not allow the build of chloroforms in the atmosphere. Minimal use of nitrogen fertilizers will not allow nitrogen oxides to cause secondary pollutants. Increase in vegetation like forests will make sure that carbon dioxide is used and so it will not cause the greenhouse effect. Limited use of fossil fuels will not add carbon dioxide, methane, oxides of sulphur etc and thus environment can be saved from their deleterious effects. On the other hand increase use of ACs, refrigerators, production of plastic forms and aerosol spray can propellants are harmful to the environment in a great deal because they cause ozone hole as well as global warming.

The Kyoto protocol is an international treaty which extends the 1992 united nations framework convention on climate change (UNFCC) that commits state parties to reduce greenhouse gas emissions, based on the scientific consensus that global warming is occurring.

'Good ozone' is found in the upper part of the atmosphere called the stratosphere and it act as a shield by absorbing ultraviolet radiations from the sun. UV rays are, highly injurious to living organisms. 'Bad ozone' is formed in the lower part of atmosphere called troposphere and it harms plants and animals.

Ozone-depleting substances (ODS) are substances that react with ozone present in the stratosphere and destroy the same. The major Ozone-depleting substances are chlorofluorocarbons (14% of total depletion), nitrogen oxides (3.5% depletion), sulphur dioxide, halon, carbon tetrachloride, methyl chloroform, chlorine, etc.

Ozone depletion is occurring widely in the stratosphere, particularly marked over the Antarctic region.

Ozone depletion occurs widely in the stratosphere due to an increased amount of $ { CFC }{ s } $ which causes various types of skin cancer and mutations.