Unit 3 - Human Population and Its Impact On The Environment Flashcards
Give reasons for the increase in the population of the world
- Increased life expectancy
- Better healthcare (hygiene, education, food, clean water, vaccines)
- Developing nations
Effect of the rising population: How do humans reduce the amount of land avaliable for animals and plants?
- Farmland - makes food and reduces habitats avaliable for other species
- Housing - increased population means the increased use of land to produce domestic buildings (houses, schools, hospitals, shops)
- Mining and Industrial use of land - increased use of natural resources
Effect of the rising population: How raw materials are bieng used up by the population
- Fossil fuels - gas, oil, coal
- Metal ores, stone
Effect of the rising population: Effects of more waste being produced
- Water pollution - waste is put into the sea
- Air pollution - Co2, carbon monoxide, acid rain
- Land pollution - we bury waste in landfills
Why is rain water naturally acidic?
Co2 is dissolved into rain and it produces carbonic acid
Explain how acid rain forms
- Sulfur dioxide from factories mixed with water vapour to create sulfuric acid
- Oxides of nitrogen mix with water vapour and produce nitric acid
These both mix with rain and create acid rain
Name 5 ways acid ways damages
- Corodes metals and limestone
- Damages leaves and makes them fall off
- Damages roots (meaning they can’t uptake minerals from the soil)
- Minerals are washed out of soil as it becomes acidic
- Water becomes acidic meaning the animals and plants that live in the water die
Describe how damage by acid rain can be reduced
- Lime is added to lakes and soil to neutralise acid
- Factory chimneys have gas scrubbers (to absorb sulfuric acid before it goes into the atmosphere)
- Cars are now fitted with catalytic converters which reduce the amount of gas released
- Using less fossil fuels (this can just mean turning lights off at home)
- Treat coal before burning it to remove sulfur impurities
Explain how global warming occurs
- (infrared) Radiation from the sun travels through space to the Earth
- The radiation reaches the Earth and heats the Earths surface
- The radiation is then reflected back into the atmosphere and leaves into space
- Certain gases (greenhouse gases) can trap the radiation in the atmosphere which heat up the Earth and Air further
Name 2 greenhouse gases
- Methane (this is 4x more effective at trapping radiation in atmosphere)
- Carbon Dioxide
Name the effects of Global Warming
- Sea levels rise - when it gets warmer it expands
- Polar Ice caps melt - melted ice runs into the sea, causes sea levels to rise even more
- ^ Causes flooding of low level land eg Holland
- Reduction in species diversity - could be reduced if some species ar eunable to survive due to the change in climate
- Changed in migration - eg some birds may go further north if the North is getting warmer
- Change in weather patterns - Its thought that many regions will suffer more extreme weather eg longer hotter drought
What is DDT
DDt is a chemical used as a pestiside. It is one method of controlling
What are pesticides used to control?
Animal population
What are Herbiscies used to control?
Plant population
Why was DDT found to be bad?
It was found to build up in food chains and kill animals at the top of the chain due to bioaccumulation (aka a high concentration)
