The Anthropocene

Question 1

Holocene

Answer 1

stability

Question 2

anthropocene

Answer 2

the modern era, dominated by humans (agriculture began 10 000 years ago when it was warm and stable. people became less nomadic)

Question 3

1950-present

Answer 3

the great acceleration

Question 4

people and resource use

Answer 4

7 billion people
1 billion in 1800 (took 100 000 years)
energy usage has increased - fossil fuels (1750-1800)
land usage has increased

Question 5

ecological footprints

Answer 5

quantification of human claims on the global resources by adding up energy, food, materials and services and estimating land usage

• higher standard of living = higher footprint
• footprint might exceed SA of earth

Question 6

nitrogen

Answer 6

• nitrogen is needed for proteins, nucleic acids etc.
• needs to be converted to NH3 or NO3-
• crops, harvested yearly, deplete nitrogen - fertiliser added

Question 7

fertiliser usage

Answer 7

140 million tonnes of fixed nitrogen added each year - comparable to microbe fixation
10% in food
rest washes off
denitrifying bacteria return it to atmosphere - some as N2O (greenhouse gas)

Question 8

eutrophication

Answer 8

added nutrients lead to increase in algae and cyanobacteria - heterotrophic organisms feed on algae and cyanobacteria - aerobic respiration decreases O2 in water creating dead zones

Question 9

phosphate fertilster

Answer 9

run off - eutrophication

• cattails and introduced species increase, decreasing biodiversity
• cannot chemically manufacture (like N), must mine (finite)

Question 10

what can be done?

Answer 10

increase yield, not land usage
genetic engineering - increase yield, nutritional value and pest resistance
reduce food spoilage