Human Impact

Question 1

What has been the human impact on climate?

Answer 1

Current data trends indicate a steady increase in the concentration of carbon dioxide levels in the atmosphere.

Question 2

Describe the greenhouse effect.

Answer 2

Increase in the Earth’s average atmospheric temperature. This may lead to polar ice melts, changing shorelines and changing world weather patterns.

Question 3

State the effects of increased human population growth on the environment.

Answer 3

• Land clearing leading to overuse and erosion (soil degradation).
• Habitat destruction.
• Exploitation of the sea.
• Acid rain.
• Damming.
• Radiation.

Question 4

Explain some examples of huamn impacts on the environment.

Answer 4

• The removal of forests and over-cropping has caused a rise in the water table and an increase in salinity.
• Removing rainforests in the tropics has reduced humidity and may then efect rainfall
• Top soil removed from eroded areas has decreased the rate of revegetation.

Question 5

Define biodiversity.

Answer 5

Refers to the variety of species and their relative abundance in the biosphere.

Question 6

What happens if a species is lost from an ecosystem?

Answer 6

It may trigger a cascade of sequential effects where a number of changes occur that may result in the loss of other species.

Question 7

Describe the importance of biodiversity.

Answer 7

Provides variation within the gene pool of the earth, which allows communities to continue to adapt by natural selection if the environment changes.

Question 14

Why is biodiversity important?

Answer 14

1. Humans rely on other living organisms (food, shelter, medicine, textiles)
2. All life on earth is interconnected, including humans. Upsetting the balance can have severe effects.
3. All life should be respected - for humans to decide what lives and dies is a sign of our arrogance.
4. The diversity of life has an aesthetic sppeal that all should be able to enjoy.