HUMAN IMPACT ON THE ENVIRONMENT Flashcards
climate
refers to the long-term weather conditions of an area
main gases that make up the atmosphere
- nitrogen
- oxygen
- water vapour
- greenhouse gases
what are greenhouse gases
- carbon dioxide
- methane
- nitrous oxide
- ozone
- chlorofluorocarbons(CFC’s)
greenhouse effect
when greenhouse gases absorb infrared(long wave radiation) long wave radiation emitted from the earth and prevent it from escaping back into the atmosphere
why is the greenhouse effect important
it keeps the earth warm so that life can be sustainable
enhanced greenhouse effect
when there is an increase in the concentration of gases resulting in a significant rise in the average temperature of the surface of the earth over a period of time, also known as global warming
what causes an increase in concentration of CO2 in the atmosphere
- burning of fossil fuels for electricity, to power vehicles and for industrial purposes
- deforestation by cutting trees and removing vegetation which decreases the amount of CO2 taken up by plants, therefore there is an increase in amount of CO2 available on the atmosphere
what causes an increass in concentration of the methane in the atmosphere
- increased number of landfills because decaying organic matter in waterlogged soils such as landfills releases methane
- increased number of livestock because ruminants like cows release methane gas through digestive tracts
- mining of coal
what does increase in temperature lead to
- more evaporation of water, leading to increased precipitation, therefore increasing potential for flooding
- rising sea levels caused by melting of glaciers and ice caps which therefore increases the potential of flooding
- increased wildfires therefore increasing the chances of soil erosion and eventually desertification
- increased loss of biodiversity because the species are unable to cope with rapidly rising temperatures eventually leading to desertification
- increased droughts in some areas leading to desertification and food insecurity
carbon footprint
a measure of the total amount of carbon dioxide emissions of an individual, a defined population or a company per year
strategies to reduce the carbon footprint
- reuse and recycle therefore less fossil fuels burnt in the production of the material
- drive less by using bicycles, walk or use public transportation
- reduce the need for heating by insulating walls and build energy efficient homes
- carbon offsetting by using alternative energy and reforestation to act as a carbon reservoir
- technological developments to decrease the amount of energy needed for production/decreasing the dependency on carbon emitting fuels
cause of the destruction of the ozone layer
chemicals called CFC’s released by refrigerators, aerosol sprays and fast food packaging
what is the ozone
ozone(O2) is a greenhouse gas found at low concentrations and they absorbs the ultraviolet Ray’s from the sun
impact of failing to reduce the destruction of ozone layer results in
- there’ll be a significant increase in the number of skin cancer cases
- uv Ray’s reaching the earth’s surface may cause a permanent damage to eyes
factors that influence the availability of water
- construction of dams
- destruction of wetlands
- water wastage
- cost of water
- poor farming practices
- droughts and floods
- boreholes and their effect on aquifers
- water recycling
- exotic plantations and depletion of the water table
construction of dams
construction of dams increase the quantity of water stored
why shouldn’t wetlands be destructed
- because they influence both the availability and quality of water
- they provided water for domestic and livestock use as well as for irrigation
- vegetation in the wetlands also helps in purifying the water naturally
how is water wasted
- water used for irrigation is lost due to poor farming practices
- wastage of water through leaking taps and toilets and faulty pipelines
how can water wastage be reduced
- it can be reduced by reducing the pressure in the pipes
- by educating people to use water wisely
- by maintaining all plumbing in good condition
what is the cost of water influenced by
- by the costs involved in increasing the availability and quality of water
- cost per kilolitre of water increases with increased use if water which is meant to discourage over-use of water, thus allowing for sustained use
- certain amount of water is available for free to all citizens to ensure that water is available to the poorest
how do poor farming practices affect the availability of water?
- fertilizers and pesticides decrease the amount of clean water available
- over-grazing can lead to soil erosion
how do droughts and foods affect the availability of water
- water availability decreases
2. natural vegetation can hold back water from floods
use if boreholes
- they increase water availability in areas that do not have direct access to other sources of water
what happens when you consistently use boreholes
it will eventually lead to the drying up of aquifers
hiw do exotic plantations decrease the depth of water tables
- some exotic plants she large quantity of water from the ground, therefore decreasing the level of the water table, making less water available
how can we prevent the depletion of water availability
- water recycling-where the existing water is used for more than one purpose and sewage can be treated and reused again, but not for human consumption
factors that influence the quality of water
- eutrophication and algal bloom
- thermal pollution
- pollution of water through domestic and agricultural use
- mining
- alien plants
- water purification
eutrophication and algal bloom effect on quality of water
- water used for agriculture might contain pesticides and fertilizers which pollute the water in rivers and dams causing eutrophication
- therefore there can be N increase in algal growth also known as algal bloom
- thus depleting the oxygen level in the water, and therefore reducing the potential for life in such water
thermal pollution effect on quality of water
- heating of water is caused by the use of water in the cooling of power-stations andin industries
- heated water has a lower oxygen content making it difficult to support life
how is water polluted through domestic and agricultural use
- domestic water may contain detergents and pathogenic bacteria which has to be treated before it can be used again
- water that’s used for industrial purposes may contain many heavy metals, oils, heat and fertilizers
- fertilizers and pesticides may run off into rivers, ponds and dams and pollute water
mining effect on quality of water
water near mines is generally acidic, toxic and hot and contribute to alien plants
alien plants effect on quality of water
- they block waterways, which reduces light for other aquatic plants resulting in decomposition
- bacteria then deplete the oxygen supply in the water
how can quality of water be restored
quality of water can be improved through purification methods of the water
food security
access, by all people at all times, to adequate , safe and nutritious food for a healthy and productive life
factors that influence food security
- exponential growth of the human population
- droughts and floods
- poor farming practices
- alien plants and reduction of agricultural land
- loss of wild varieties and its impact on gene pools
- genetically engineered food
