f5 chap 10 environmental sustainability Flashcards
whats the definition of environmental sustainability?
environmental condition that remains the same without any reduction or depletion of natural resources, with an assured quality of the surrounding environment for a long period of time
whats a cause of not being able to conserve the environment?
increase in human population
what are the threats to the environment?
1 climate change and global warming
2 deforestation and loss of biodiversity
3 eutrophication
4 pollution
5 human population growth explosion
whats climate change?
change in temperature of the earth, rainfall distribution and drastic changes of the winds.
what does climate change and global warming result in?
greenhouse effect phenomenon
explain the greenhouse effect phenomenon
1 When sunlight enters the atmosphere of the earth,
some of the light is reflected back into space in the form
of infrared rays.
2 When heat energy is released, most of
the energy will be absorbed by the greenhouse gases
such as carbon dioxide, methane, nitrogen oxide and
chlorofluorocarbon (CFC) which exist in the atmosphere
of the earth,
3 thus preventing the infrared rays from being
reflected back into space.
whats the positive effect of greenhouse effect phenomenon?
Heat energy that is not reflected keeps the earth at an average temperature so it is not too cold for the survival of organisms
how has human activities over the last decades contributed to the greenhouse effect?
human activities such as burning of fossil fuels and deforestation have caused the increase in concentration
of greenhouse gases. Thus, more heat energy is trapped which increases temperature of the earth
what are the factors causing greenhouse effect and the respective greenhouse gases involved?
burning of fossil fuels (carbon dioxide)
deforestation (carbon dioxide)
animal farming (methane)
agricultural activities (nitrogen oxide)
usage of cooling substances (chlorofluorocarbon, CFC)
whats the result of el nino phenomenon
causes extreme hot and dry weather which causes draught
whats the result of la nina phenomenon?
causes unusual heavy rain which causes serious floods
definition of deforestation?
action of clearing a wide area of trees in a large scale
whats the purpose of deforestation?
1 to obtain timber for construction work, furniture, and paper
2 mineral mining
3 opening new areas to carry out agricultural activities
4 building residential areas and roads
negative impact of deforestation activities?
- soil erosion
- flash floods
- climate change
- loss of biodiversity
- disruption of nitrogen cycle, water cycle, and carbon cycle
- loss of water catchment areas
definition of eutrophication?
process that occurs when the water ecosystem becomes rich with nutrients, resulting in changes to the structure of the ecosystem
what are the effects of eutrophication?
algal blooms, death of aquatic life and deterioration of water quality
how does excessive usage of nitrate and phosphate fertilisers cause eutrophication?
- excessive nitrate and phosphate residuals flow into lakes & rivers w help of rain water
- increase in nitrate & phosphate stimulates rapid growth of algae, covering the water surface (eutrophication)
- this reduces the penetration of sunlight into the water
- this causes rate of photosynthesis of aquatic plants to slow down and content of dissolved oxygen in the water decreases.
- this causes aquatic plants and animals to die
- abundance of algae and death of aquatic organisms increases the population of decomposer bacteria
- decomposer bacteria disintegrate dead aquatic plants and animals in the presence of oxygen, which causes oxygen reduction in water
- this increases biological oxygen demand (BOD)
definition of biochemical oxygen demand?
BOD is the total amount of oxygen needed by microorganisms such as bacteria and fungi to decompose organic materials in water
what does high BOD level indicate?
low quality of water source bc there are many organic substances and decomposed microorganisms in the water
what does low BOD level indicate?
water is of good quality as its unpolluted and dissolved oxygen content is high
what are the types of pollution?
air, thermal, noise
when does air pollution happen?
happens when theres an increase in the pollutant substances such as gases, smoke, dust and particles in the atmosphere which affect health and lives of human beings, animals and plants
what are the pollutant substances in smoke from industrial factories?
- sulphur dioxide
- nitrogen oxide
- dust
- carbon monoxide
- carbon dioxide
what are the pollutant substances in exhaust fumes from vehicles?
- nitrogen oxide
- carbon monoxide
- lead
- smoke and soot
- hydrocarbon gases
how is acid rain formed?
1 burning of fossil fuels by charcoal burning plants, industrial factories and vehicles releases carbon monoxide, nitrogen oxide, and sulphur dioxide into atmosphere.
2 these gases combine with water vapour in the atmosphere to form nitric acid and sulphuric acid and later comes down as acid rain
what are the pollutant substances in open burning?
- carbon dioxide
- smoke and soot
effects of acid rain?
1 infertile soil due to 5> pH level
2 destroys leaf tissues and damages roots of plants
3 reduces plankton population which is food source for fish
4 affects food chain which can cause death of various organisms
5 causes skin diseases and tissue damage in humans
definition of thermal pollution
deterioration of water quality due to excessive heat dissipation into water caused by processes that change the water temperature.
what causes thermal pollution?
- water is used as cooling agent to cool down generators in industrial factories and hydroelectric power generator plants
- hot water produced is then discharged into rivers or lakes causing thermal pollution
- increased temp of river is unsuitable for aquatic habitats
- as temp of water rises, dissolved oxygen content in water will decrease and threaten survival of aquatic lives