Human Influences On The Environment Flashcards
What is the greenhouse effect
The sun’s heat energy enters the atmosphere and reflects back but hits a layer of greenhouse gases
What’s deforestation
The burning of trees
What causes co2 levels to increase
Burning of fossil fuels
Cars
Power stations
How does deforestation increase the amount of co2
Trees can’t photosynthesis and remove co2
Increased temperature means
Polar ice caps melt Sea levels rise Change in ocean currents Warmer water where once it was cooler Changes in weather patterns (droughts/floods)
Name 3 greenhouse gases
Methane
Carbon dioxide
Water vapour
Heat energy from the Earth’s surface is radiated into __________ but some of it is absorbed by _______ in the atmosphere. This ________ the atmosphere
Space
Gases
Warms
Holes in the ozone layer are thought to have been caused by chlorine from long-lived _______
CFCs
Name 3 things that CFCs are used in
Aerosols
Refrigerator coolants
Expanded plastics
CO2
Comes from:
Effect:
Comes from combustion of fossil fuels
Effect: Traps heat in the atmosphere (greenhouse effect)
Carbon monoxide
Comes from:
Effect:
Comes from: Burning fossil fuels in limited oxygen (cars)
Effect: Poisonous. Cells don’t get enough O2. CO binds with haemoglobin instead of O2
Sulfur dioxide So2
Comes from:
Effect:
Comes from: Burning fossil fuels (factories)
Effect: Acid rain
Nitrogen oxides
Comes from:
Effect:
Comes from: Petrol and diesel burned in engines
Effect: Acid rain
Methane
Comes from:
Effect:
Comes from: Cow flatulance, paddy fields, decomposing waste in landfill
Effect: Greenhouse effect
Ph of normal rain:
5.5 (slightly acidic because co2 is dissolved in it (carbonic acid))
How is acid rain formed
Nitrogen oxides released from burning fossil fuels + rainwater —-> nitric acid which is very acidic
What 3 effects does acid rain have
Soil becomes acidic which damages root hairs
Damage to leaves + trees
Death of fish in rivers + lakes
5 things that pollute water
Sewage Industrial waste Oil Pesticides Fertilizers
Explain the process of eutrophication
Rain washes fertilizers out of the soil and washes nitrates into rivers/ponds
The nitrates make the algae in the water grow really fast
The algae grows quickest forming an algal bloom
This covers the surface meaning that the plants at the in the water can’t receive light or photosynthesise leading to death.
Then decomposers break down the dead plants carrying out respiration and using up oxygen up in the water. Fish die due to lack of oxygen.
Eventually the pond runs out of oxygen and the only organisms that can survive are anaerobic bacteria
Rain washes fertilizers out of the soil and washes ___________ inter rivers/ponds
The nitrates make the ________ in the water grow really fast
The algae grows quickest forming an _______ ________
This covers the surface meaning that the plants at the in the water can’t receive _________ so they can’t __________________ leading to death.
Then decomposers break down the dead plants carrying out ____________ and using up _________up in the water. Fish die due to lack of oxygen.
Eventually the pond runs out of oxygen and the only organisms that can survive are ___________ bacteria
This process is called ____________________
Nitrates Algae Algal bloom Light Photosynthesise Decomposers Respiration Oxygen Anaerobic Eutrophication
Most organic waste matter is biodegradable. It is broken down by ________________ in the water
Micro-organisms
If there is too much organic waste then the number of micro-organisms ______________
Increases
As micro-organisms break down organic waste they also ___________ using up __________. The water becomes _________ causing fish to die due to a lack of oxygen
Respire
Oxygen
Anoxic
One of the most accurate ways of testing for pollution is to look at animal life present in a _______ sample. Certain creatures particularly insects die at different levels of pollution. The presence of these indicator species can be used to show how badly a waterway is polluted
Water sample
Where could large amounts of nitrates and phosphates in a pond/river come from
Fertilizers via leaching
What is the term for ‘cutting down large areas of trees’
Deforestation
What is overgrazing
Allowing cattle to spend too long on an enclosed portion of land
What does anoxic mean
Without oxygen
What is overfishing
Fishing too much, killing too many fish
What is trawling
Dragging a net along a sea bed killing all sorts of species
What is desertification
The process in which fertile land becomes desert
3 causes of desertification
Overgrazing
Deforestation
Poor irrigation (watering) not enough water
How to prevent desertification by overgrazing
Fertilise the land so that plants can continue to grow
How to prevent desertification by deforestation
Plant trees (reforestation)
2 ways of preventing desertification
Fertilise the land so that plants can grow
Plant trees (reforestation)
Reduce the effect of the wind by making barriers and stabilising sand dunes with plants
