Introduction

Question 1

Explain what scientists are calling Anthropocene

Answer 1

A new era or time period where a lot of Earths processes are caused by human action

Question 2

what systems do humans have a huge impact on

Answer 2

• carbon cycle
• nitrogen and phosphorus cycle
• ecosystem function

Question 3

briefly outline some trends found in human population numbers

Answer 3

• Human populations have exploded however growth rates in more industrial areas is beginning to slow reaching a demographic transition point (where high birth rates shifts to higher death rates)
• carrying capacity of humans thought to be between 7.7- 12 billion

Question 3

what are the 5 major anthropogenic threats

Answer 3

1) habitat destruction and degradation- 50% of all inhabitable land converted for human use and remaining land degraded

2)climate breakdown - rising temps

3) overexploitation e.g. overfishing lead to pop crash of 99%

4) invasive species - brown tree snake in Guam caused alot of extinctions of small forest species

5) pop decline/ extinction = since 1960 average decline of 60% , biomass of flying insects declined 76-82% over 27 yrs

Question 4

what happens to resource use with higher populations

Answer 4

its been seen that more developing countries have a higher ecological footprint (more resource use) e.g. America makes 5% of population but contributes to 24% of world energy consumption

= this endless growth is unsustainable

Question 5

are we in the 6th mass extinction?

Answer 5

mass extinction = 70% loss of species, past ones seem to be due to rapid global temp changes
- so far only 1% of species gone extinct but many are threatened with extinction
- not levels seen in previous mass extinctions
- but current extinctions rates are equal to that seen in previous ones