Human influences on the enviornment

Question 1

Where does Sulfur Dioxide come from?

Answer 1

Combustion of fossil fuels which have sulphur impurities creates sulphur dioxide

Question 2

Where do Nitrogen Oxides come from?

Answer 2

Produced from the combustion of fossil fuel

Question 3

How does Sulfur Dioxide and Nitrogen oxides turn into acid rain?

Answer 3

Sulfur DIoxide and Nitrogen oxides react with oxygen and dissolve in rainwater to produce dilute sulphuric acid or nitric acid, which leads to acid rain

Question 4

How does air pollution lead to acid rain?

Answer 4

• Nitrogen oxides released by cars
• Sulfur Dioxide released by combustion of fossil fuels
  -This creates acidic gases which is then blown by wind until they dissolve into the rainwater and turn into acid rain

Question 5

What is a greenhouse gas?

Answer 5

A gas that absorbs infared radiation from the sun so it remains trapped in the atmosphere

Question 6

What are the most important greenhouse gases?

Answer 6

• Water vapor
• CO2
• Methane
• Nitrous Oxides

Question 7

What human activities can lead to increasing levels of CO2 and Methane?

Answer 7

-CO2 is released by the combustion of fossil fuels
- Cattle produce methane as they digest grass and release

Question 8

Describe the greenhouse effect?

Answer 8

• The sun emits rays that enter the earth’s atmosphere
  -The heat bounces back from the earth’s surface
• Some of this heat is reflected back to space
• Some heat is absorbed by greenhouse gasses and trapped within the earth’s atmosphere (This is normal)
  -As greenhouse gas levels rise due to human activities, earth’s average temperature rises beyond normal (an enhanced greenhouse effect). This causes global warming

Question 9

What are some consequences to global warming?

Answer 9

• Ocean temperatures increase, leading to the melting of the polar ice caps and contributing to rising sea levels.
• Increasing temperatures cause extreme weather like super storms, floodings, or droughts
  -Changes/ Loss of habitats due to extreme weather events
• Decreases in biodiversity as food chains are disrupted due to some animal extinctions

Question 10

How do pesticides enter water sources?

Answer 10

-Pesticides are sprayed on crops to prevent insect damage
- Runoff is caused when too much of this is sprayed, they can runoff and enter water sources

Question 11

How do pesticides affect biodiversity?

Answer 11

Bioaccumulation occurs: These chemicals can’t be broken down by organisms, these chemicals can build up in aquatic animals. At each stage of the food chain increasing levels of these chemicals build up in organisms and can build up to lethal toxic levels, leading to death or failure to breed. This is called biomagnification

Question 12

How does untreated sewage enter water sources?

Answer 12

Lack of sewage treatment in inhabited areas can lead to sewage being either leaked or pumped into water sources

Question 13

How does untreated sewage affect biodiversity?

Answer 13

Untreated sewage is a good source of food for bacteria which can increase rapidly. These bacteria can use all the oxygen in the water very quickly (as they aerobically respire). This lack of oxygen can lead to fish and other aquatic animals to die. This is called eutrophication

Question 14

How do fertilisers enter water sources?

Answer 14

Runoff occurs when too much fertiliser is added, this leads to fertilisers entering nearby water sources

Question 15

How do fertilisers affect biodiversity?

Answer 15

Fertilisers can cause increased growth of algae and water plants. Dead plants and algae are a good source of food for bacteria which can then kill the local fish and aquatic animal population through eutrophication

Question 16

What is eutrophication?

Answer 16

When bacteria use most of the oxygen in the water because they aerobically respire. This lack of oxygen will then kill the aquatic animals.