3- How Humans Effect The Environment

Question 1

What are the three main things humans pollute? And how?

Answer 1

Waterways - sewage and toxic chemicals
Air - smoke and gasses
Land - toxic chemicals (pesticides and herbicides)

Question 2

How do people pollute the land?

Answer 2

Sewage - if parasites and chemicals are not treated
Household and industrial waste - chemicals (even radioactive) leak out
Farming methods - chemical fertilisers
Herbicides and pesticides

Question 3

What are 1) herbicides and 2) pesticides?

Answer 3

1) weed killers
2) insect killers
Both poisons which get into the soil and therefore food chain

Question 4

How do people pollute water?

Answer 4

Herbicides, pesticides and fertilisers are all washed into rivers
Untreated sewage
Toxic chemicals leaks from landfill

Question 5

How do people pollute the air?

Answer 5

Burning fuels (produce eg. sulphur dioxide which forms acid rain)

Question 6

What happens with acid rain?

Answer 6

Sulphur dioxide dissolves in water vapour in the air, causing acidic solutions to fall as acid rain which kills organisms and damages plant life

Question 7

What is deforestation?

Answer 7

Many trees are cut down - often in tropical areas for timber and agricultural land

Question 8

What effects has deforestation had?

Answer 8

Increase the release of carbon dioxide in the atmosphere
Reduced the rate that carbon dioxide is removed for the atmosphere
Reduced biodiversity

Question 9

Why do humans do deforestation?

Answer 9

So crops can grow to produce ethanol based biofuels

Cattle and rice fields (produce methane)

Question 10

How has the destruction of peat during deforestation effected the atmosphere?

Answer 10

Increase of carbon dioxide.

It is used as compost, which is decayed by microorganisms - releasing carbon dioxide

Question 11

In the normal balance of nature, what is carbon dioxides cycle?

Answer 11

It is released into the air by respiration and removed by plants and algae (also dissolving in the earths waters)

Question 12

What is greenhouse gasses and what do most scientist believe about them?

Answer 12

They are the levels of carbon dioxide and methane in the atmosphere
Most scientists believe they contribute to global warming

Question 13

What could a slight increase in the Earth’s temperatures do?

Answer 13

Cause noticeable changes to the climate 
A rise in sea level (the ice caps melt) 
Reduction in biodiversity 
Change in bird migration
Distribution of species changes

Question 14

What are biofuels? Give two examples

Answer 14

Fuels made from natural products
Ethanol based fuels
Biogas

Question 15

How are ethanol based fuels produced?

Answer 15

By anaerobic fermentation
Microorganisms respire anaerobically to produce ethonal (using sugars from crops as energy)
Glucose is produced from maize starch through carbohydrate which can be fermented by yeast to produce ethanol

Question 16

What is the advantage to distilling ethanol and using it as a fuel in motor vehicles?

Answer 16

It is carbon neutral - the carbon dioxide used for photosynthesis is returned to the atmosphere when ethanol is burnt

Question 17

How can biogas be produced?

Answer 17

During anaerobic fermentation by bacteria
Plants and waste (containing carbohydrate) can be broken down in biogas generators which provide idea conditions for bacteria.

Question 18

Describe biogas generators?

Answer 18

Suitable temperature with oxygen free conditions, well insulated with insulating jackets. Some are designed to mix the contents

Question 19

What is the gas produced by a biogas generator used for?

Answer 19

Fuel that provides energy for heating. The more methane the better

Question 20

How can we produce meat more efficiently?

Answer 20

Preventing the animal from moving (wasting energy)

Keeping the animals in warm conditions so energy isn’t wasted on maintaining body temperature

Question 21

What does sustainable food production involve?

Answer 21

Managing resources
Finding new types of food (mycoprotein)
Hunters/fishermen are monitored and restricted

Question 22

What is mycoprotein?

Answer 22

Aerobically grow on cheap sugar syrup by the fungus ‘fusarium’ it is a protein rich food suitable for vegetarians

Question 23

What is a fermenter?

Answer 23

Where microorganisms can be grown on a large scale.

It’s conditions must be controlled to ensure maximum growth

Question 24

Features of an industrial fermenter?

Answer 24

Air supply providing oxygen
A stirrer to keep microorganisms spread out
A water cooled jacket to balance the heat from the respiration
Sensors to monitor pH and temperature

Question 25

What human activities affect the environment?

Answer 25

Deforestation
Rice and cattle farms
Building dams

Question 26

What is the issue with scientists and environmental issues?

Answer 26

They don’t agree, they come up with different data and form opinions based on the data.
Some say global warming is because of greenhouse gasses, others say it is natural

Question 27

What happens when humans industrially produce things (usually)?

Answer 27

Non-renewable materials are used up

Industrial waste and pollution are produced