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BIOL 381 > Lecture 1: Anthropocene > Flashcards

Lecture 1: Anthropocene Flashcards

1
Q

Anthropocene=

A

a proposed epoch dating from the start of significant human impact on Earth’s geology & ecosystems

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2
Q

geologic time = ____ time
what is the geological time scale? (GTS) List in order

A

deep

Eons
Eras
Periods
Epochs
Ages (subunits of epochs)

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3
Q

How old is the Earth? (aprox)

A

4.6 billion years old

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4
Q

___ are the largest time unit in the GTS
____ are the smallest time unit in the GTS

A

eons
ages

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5
Q

where are we now in the GTS?

A

eon: phanerozoic
era: Cenozoic
period: quaternary
epoch: holocene

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6
Q

Why is it hard to define a new epoch right now?

A

Defining a period while in it has never been done before- this is problematic

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7
Q

list a few reasons that support that we’ve entered a new epoch

A
  • human pop growth rate explosion
  • inc urbanization
  • mass extinctions
  • climate change
  • damage to ozone layer
  • anthropogenic materials (plastic, concrete)
  • coastal wetland loss
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8
Q

When did the Anthropocene start?

A

This is not solved yet!
Some proposed start dates are:
- some dates pre-industrial revolution
- 1760: industrial revolution
- 1945: nuclear weapon denotation
- 1950s: Beginning of the great acceleration; persistent industrial chemicals, plutonium from atomic weapon testing found in soil in 1951 could mark the Anthropocene

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9
Q

What’s a recent alternative to adding the Anthropocene as an epoch?

A

Anthropocene as an ongoing event, not an epoch

geological event= major transformative episode in Earth’s history that varied spatially and and temporally (they are very important and change our planet)

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10
Q

Who proposed the Anthropocene and made it popular? When?

A

Biologist Eugene Stoermer and Chemist Paul Crutzen
(in the Global Change Newsletter)
Year published= 2000

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11
Q

Pleistocene epoch=

A

ice age

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12
Q

When did Paul Crutzen suggest that the Anthropocene started?

A

In the late 18th century, when analysis of air trapped in polar ice showed the beginning of growing global concentrations of CO2 and methane

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13
Q

In 1873, Italian geologist Antonio Stoppani suggested we were entering an:

A

Antropozoic era

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14
Q

T/F
our socioeconomical trends show logarithmic growth of almost everything (population, urbanization, water use, paper production, fertilizer consumption, tourism)

A

False
These all show exponential growth :(

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15
Q

What do graphs show about our earth system trends?
eg.
- surface temp
- atmospheric CO2 and methane
- tropical forest loss
- domesticated land

A

these are all growing exponentially

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16
Q

T/F
urbanization is growing at a similar rate all around the world

A

true
people everywhere are moving to the cities for jobs

17
Q

What are some changes that are happening with Carbon?

A

overall levels of CO2 and CH4 are increasing; there are lots of fluctuations- not following trajectories of the past

18
Q

What are the 6 most important greenhouse gases? List them in order of potency, not abundance

A
  1. CO2 (most abundant, least potent)
  2. water vapor
  3. methane (21x as potent as CO2)
  4. N2O (laughing gas): 310 CO2
  5. tropospheric ozone: 1000 CO2
  6. CFCs: 4750 CO2
19
Q

___ are responsible for breaking down the ozone layer

A

CFCs (chloroflourocarbons)

20
Q

the layers inside ice cores indicate ____
The bubbles=
larger chunks=

A

seasons (summer= light, winter= dark)

bubbles= gasses from the atmosphere at a certain time

larger chunks= sediments

21
Q

T/F
the anthropogenic imbalance of the C cycle is superseded by that of the global N cycle

A

true!

Anthropogenic flux for C= +13%
Anthropogenic flux for N= +108%? (much more of a change)

22
Q

nitrogen leaves a clear trace in the geological record. Describe trends of soil nitrogen (nitrate NO3) N15, and N14

A

soil N (NO3)= doubled in the past century b/c of fertilizer

N15 is retained in animal tissued: decrease in N15= increase in N14 (more anthropogenic emissions)

23
Q

What are 2 reasons causing N14 to increase?

A
  1. Fossil fuel emissions: NOx (nitric acid etc) emitted into the atmosphere
  2. The Haber- Bosch Process
    - Artificial N fixation
24
Q

Describe the Haber-Bosch Process

A

this is artificial nitrogen fixation. It combines N gas and H gas using a metal catalyst under high heat and pressure to form NH3

NH3 gets into the N cycle b/c animals in the soil immobilize it, then die and break down

25
Q

___ is the main source of anthropogenic nitrogen fixation

A

fertilizer production (Haber Bosch process)

26
Q

What could be one of the causes of the more powerful/ frequent storms we have been experiencing recently?

A

anomalies in temp of ocean surface

27
Q

What is the Montreal Protocol?

A

the banning of CFCs to decrease damage to our ozone layer
- it is helping

28
Q

____ ___ provide habitat, water purification, etc, and they are being destroyed by urbanization and global warming.

A

coastal wetlands

29
Q

The collapse of fisheries is connected to the loss of ___

A

wetlands

also overfishing is out of control!

30
Q

What has been appearing in our oceans/ sediments?

A

anthropogenic materials
- aluminum
- concrete
- plastics
- synthetic fibers

31
Q

Explain the spikes in radioactive materials in the 1960s

A

these spikes were not natural; used for fuel of atomic weapons

the huge spike in 1964= date of atomic bomb testing

this increase in radioactive materials is evidence of anthropogenic change

32
Q

How do we define the Anthropocene?

A

= profound change in geological conditions and processes due to humans

  • must be scientifically justified
  • can’t agree: on a spatial and temporal marker for the onset of the Anthropocene
  • agree: changes are occurring- just don’t know how to categorize it
33
Q

what are 3 alternatives for the Anthropocene?

A
  1. Add the Anthropocene as a new epoch after the Holocene
  2. Replace the epoch Holocene with Anthropocene (not popular)- downgrade holocene to age
  3. the anthropocene as a new age/ stage within Holocene epoch

*know what these look like on the GTS scale

34
Q

Summary of proposed start dates/ events for the Anthropocene (9)

A
  1. Megafauna extinction- 50,000- 10,000 yr BP
  2. Origin of farming- 11,000 yr BP
  3. Extensive farming- 8,000yr BP to present
  4. Rice production- 6500yr BP to present
  5. anthropogenic soils- 3000-500ys BP
  6. New-Old world collision- 1492-1800
  7. industrial revolution- 1760- present
  8. Nuclear weapon denotation- 1945- present
  9. persistent industrial chemicals- 1950 to present
35
Q

what was the proposed formal definition of the Anthropocene in 2017 by the “working group on the Anthropocene”?

A

Anthropocene as a new epoch
- starting mid 20th century (~1945- plutonium fallout)

36
Q

In ___ Gibbard et al. proposed that the anthropocene is:

A

2022
an ongoing event, not an epoch
- this is informal, but still a geological definition (but does not appear in the GTS)

37
Q

geological event=

A

major transformative episode in earth history that vary spatially and temporally
- very important; they change our planet
- Gibbard et al. suggested that the anthropocene is an ongoing geological event

38
Q

give 2 examples of ongoing geological events

A
  1. great oxidation event (an increase of oxygen in atmosphere 2.4-2.0 Ga)
  2. forestation of continents in the middle-late Devonian
    (land was colonized by plants- very important, but didn’t happen at the same time everywhere)

BIOL 381 (22 decks)

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