human impact on the environment

Question 1

what is the greenhouse effect

Answer 1

it is a natural process that warms the earths surface. When the suns energy reaches the earths atmosphere some of the energy is reflected back into space and the rest of it is by absorbed by the earths surface and then re-radiated by the greenhouse gases

Question 2

purpose of greenhouse gases

Answer 2

they act as a insulating blanket that traps heat energy and makes the earth warm and habitable

Question 3

greenhouse gases

Answer 3

carbon dioxide
methane
water vapour
nitrous oxide

Question 4

enhanced greenhouse effect

Answer 4

• the intensifying of the greenhouse effect due to the excessive release of greenhouse gases like CO2 ,CH4 because of human activities,
• The higher the level of these gases in the atmosphere , the further increase in the earths temperature thus leading to global warming

Question 5

what human activities increase the levels of CO2 in the atmosphere

Answer 5

industrialization( the use of fossil fuels )

deforestation ( reduces the carbon sinks in the environment )

Question 6

why are forests regarded as CARBON sinks

Answer 6

trees in the forest absorb large amounts of CO2 for photosynthesis and they store this CO2 as carbohydrates , so they minimalize the amount of CO2 in the atmosphere

Question 7

use of CH4

Answer 7

traps heat more effectively than any other greenhouse gas

Question 8

human activities that emit CH4

Answer 8

• CH4 is released during production,processing,storage and distribution of natural gases
• ch4 is released into the atmosphere from animal faeces
• stored animal manure release CH4 into the atmosphere

Question 9

carbon footprint

Answer 9

the sum of all CO2 emissions resulting from your activities within a given period

Question 10

ways to personally reduce your carbon footprint

Answer 10

minimize air travel
use less electricity 
use alternative sources of energy 
decrease your fuel consumption by walking ,cycling 
eat less meat and processed foods 
insulate your home

Question 11

what is global warming

Answer 11

the increase in the earths temperature as a result of an enhanced greenhouse effect

Question 12

effects of global warming

Answer 12

• a rise in sea levels
• melting of polar ice caps and glaciers
• global shortage of food and water
• loss of biodiversity
• increase in extreme weather conditions

Question 13

what is desertification

Answer 13

the process through which semi-arid or arid land is transformed into a desert

Question 14

causes of desertification

Answer 14

• climate change
• decrease in total rainfall
• high temperatures and prolonged droughts can lead to loss of natural vegetation and crop failure

Question 15

human activities that cause desertification

Answer 15

• over-grazing
• over-cultivation
• poor irrigation
• deforestation

Question 16

effects of desertification

Answer 16

-soil erosion
-increased flooding
sand/dust storms which can lead to the loss of valuable top soil
-loss of biodiversity
-the soil releases more CO2

Question 17

The permanent destruction of trees and bushes in order to clear an area for other purposes

Answer 17

deforestation

Question 18

causes of deforestation

Answer 18

• urbanisation
• agriculture
• traditional medicine
• wood for fuel
• timber
• mineral mining

Question 19

effects of deforestation

Answer 19

-global warming
-soil erosion
-floods
loss of biodiversity

Question 20

A layer of gas that is located around the earth in that stratosphere

Answer 20

ozone layer (O3)

Question 21

Causes of ozone depletion

Answer 21

manufactured chemicals containing chlorine and bromine are known as Ozone-depleting substances (ODS)

Question 22

Effects of ozone depletion

Answer 22

damage to:

• human health
• marine life
• agriculture
• materials

Question 23

what influences water availability

Answer 23

-construction of dams
-destruction of wetlands
-poor farming practices
droughts and floods
-alien plantations