anthropocene

Question 1

L1 - anthropocene > physical perspective
1. what is the anthropocene/ physical view point. how is earth’s geological time divided and what is current geological time

Answer 1

1. time divided into hierarchical unites = eons, eras, periods and epochs. the current time = holocene epoch, quaternary period, cenzoic era and phanerozoic eon.

Question 2

L1 > anthropocene > physical perspective
how are boundaries between geological time units defined by/ who?
example
what criteria does it have to meet

Answer 2

• global boundary stratotype section and point (GSSP)
  or
  Global standard stratigraphic age (GSSA)

the GSSP is marked by significant global changes.
an example of this is the boundary between cretaceous and paleogene periods, marked by a peak in iridium from meteorite impact in rocks 66 million years old. it signalled the extinction of non-avain dinosaurs.
criteria gssp has to meet; primary marker event, secondary markers, global correlation, continuous sedimentation an exact location, accessible and provisions for preservation

Question 3

L1 > anthropocene > physical perspective
how would the anthropocene be officailly recognised?

Answer 3

• need consensus from the geological community and then a formal ratification process invovlving multiple scientific communities and organisations.

Question 4

L1 > anthropocene > physical perspective
what are the arguements for the anthropocene?

Answer 4

• the great acceleration (steffen et al 2004) > created graphs that showed socio-economic activy and earth surface trends
• the plasticene > synthetic marker
• CO2 and greenhouse gasses concentration > look at global mean surface temp, rising, drastic spike in the last 100 years, currently highest temp
• planetary boundarie > 9 boundaries that humans can cross and still continue to develop and thrive. in 2023 we have crossed 6/9 boundaries. after a boundary is crossed it puts more stress on earth system.

Atmospheric gas changes (CO2, radionuclides).

Synthetic materials like plastics.

Stratigraphic markers, such as spheroidal carbonaceous particles and isotopic changes in sediment layers (Waters et al., 2018).

Question 5

Outcome of Recent Debates

Question: What was the outcome of the Anthropocene debates?

Answer 5

Answer: In 2023, the Subcommission on Quaternary Stratigraphy voted against formalizing the Anthropocene as an epoch. It remains a cultural concept, with suggestions to define it as an event rather than an epoch (Gibbard et al., 2022).
12/17 voted against it becoming a new epoch

Question 6

Planetary Boundaries

Question: What are planetary boundaries?

Answer 6

6:
Answer: A framework of nine limits within which humanity can sustainably operate, including boundaries for climate change, biodiversity loss, and nitrogen cycles (Stockholm Resilience Centre, 2023).

Question 7

what did lewis and maslin propose in 2015
Question: What are the two main proposed start dates for the Anthropocene?

Answer 7

proposed two starting dates for the anthropocene
1610 - orbis spike
1964 - radionuclide spike

1610 (Orbis Spike): Coincides with a 7–10 ppm drop in atmospheric CO2 due to reforestation after the collapse of Indigenous populations in the Americas.

1964 (Radionuclide Spike): Linked to peak fallout from nuclear bomb tests during the “Great Acceleration.”

Question 8

The Orbis Spike

Question: What is the Orbis Spike? who prosed the idea

Answer 8

Answer: A 1610 event marked by a significant CO2 drop due to the reforestation of abandoned agricultural lands following the decline of Indigenous populations in the Americas (Lewis & Maslin, 2015). european contact in Americas lead to around 50 million deaths = reforestation and decreased fire use for land management = land regrowth and carbon sequestering from agricultural abandonment

• analysis of atmospheric and marine carbon isotopes showed 1600 huaynaputina eruption and ocean feedbacks contributed aswell

Question 9

The Radionuclide Spike

Question: What is the significance of the 1964 Radionuclide Spike?
who prosed the idea it could be starting point for anthropocene

Answer 9

(lewis and maslin 2015)
Answer: It provides a clear, globally synchronous stratigraphic marker linked to atmospheric nuclear testing, highlighting human technological impacts (Lewis & Maslin, 2015)
- peak in radianuclide fallout from atmospheric nuclear bomb tests (GSSP)
- shows human activities capacity to induce planetry scale environmental change

Question 10

Cultural vs. Geological Concept

Question: Is the Anthropocene more of a cultural or geological concept?

Answer 10

Answer: The Anthropocene is increasingly seen as a cultural and historical framework for understanding human impact, rather than a formal geological epoch (Nature, 2024). - as it was rejected to become a holocene

Question 11

Key Sites for Evidence

Question: Which site has been proposed as a stratigraphic marker for the Anthropocene?

Answer 11

Answer: Crawford Lake in Canada, with its well-preserved sediment layers containing evidence of human activity, such as fossil fuel combustion particles and nuclear isotopes (McCarthy et al., 2023).

Question 12

formalising the anthropocene
Anthropocene Working Group (AWG)

Question: What is the role of the Anthropocene Working Group (AWG)?

Answer 12

Answer: The AWG was formed to evaluate and formalize the Anthropocene as a geological epoch.
They published extensive research, including a 2018 paper detailing potential stratigraphic markers and candidate sites, and proposed Crawford Lake as a key site in 2023 (Waters et al., 2018; McCarthy et al., 2023).

Question 13

Key Sites for Evidence

Question: Which site has been proposed as a stratigraphic marker for the Anthropocene?

Case Study - Crawford Lake

Question: Why is Crawford Lake significant in the Anthropocene debate?

Answer 13

Answer: Crawford Lake in Canada, with its well-preserved sediment layers containing evidence of human activity, such as fossil fuel combustion particles and nuclear isotopes (McCarthy et al., 2023).

Answer: Crawford Lake in Canada has well-preserved annual sediment layers (varves) that record human impacts, including spheroidal carbonaceous particles from fossil fuel combustion and isotopic markers from nuclear testing. This high-resolution record makes it a leading candidate site for defining the Anthropocene (McCarthy et al., 2023).

Question 14

Human Geography’s Contribution

Question: What does a human geography perspective contribute to the study of the Anthropocene?

Answer 14

Answer: Human geography explores the socio-spatial inequalities and interdependence between human and planetary life. It highlights how changes in the Anthropocene exacerbate inequalities and calls for just and sustainable responses (Cook et al., 2015).
physical geog gives science

Question 15

Causes of Anthropocene Change

Question: What are the primary human-driven causes of changes in the Anthropocene?

Answer 15

Answer:

Population Growth: Rapid increases intensify resource use.

Non-renewable Energy Use: Over-reliance on fossil fuels.

Over-production and Disposability Culture: High waste generation, with poorer nations disproportionately affected by plastic leakage.

Loss of Seasonality and Harmony with Nature: Shift from traditional practices to industrialization.

Human Exceptionalism: The belief in human dominance over nature (Malm & Hornborg, 2014).

Question 16

Uneven Impacts of the Anthropocene

Question: How are the impacts of the Anthropocene uneven?

Answer 16

Answer:

Colonial Legacies: Industrialization driven by colonial exploitation and slavery.

Global Inequalities: A single U.S. citizen emits as much as 500 citizens in low-income nations (Malm & Hornborg, 2014).

Intergenerational Injustice: Future generations bear the brunt of climate crises (Nakate, 2019).

Inter-species Injustice: Human activities disrupt ecosystems, threatening biodiversity.

Question 17

The Anthropocene as a Social Narrative

Question: Why is the Anthropocene considered a global social narrative?

Answer 17

Answer: It provides a story of how human activities have co-evolved with Earth systems, shaping past, present, and future challenges. This narrative helps frame societal transformation and offers models for sustainable futures (Veland et al., 2018).

Question 18

What Needs to Happen

Question: What actions are necessary to address Anthropocene challenges?

Answer 18

Answer:

Rapid Decarbonization: Transitioning to renewable energy.

Circular Economy: Emphasizing recycling and reducing waste.

Voluntary Consumption Reductions: Especially by affluent nations.

Ecosystem Protection: Safeguarding biodiversity.

Mindset Change: Embracing interdependence and justice (Head, 2015)

Question 19

Living as ‘Anthropoceneans’

Question: What does it mean to live as an ‘Anthropocenean’?

Answer 19

Answer: Anthropoceneans embrace uncertainty, recognize their embeddedness in nature, prioritize justice, and adapt to living in harmony with the Earth through cultural and ecological respect (Head, 2016).

Question 20

The Anthropocene Meeting Point

Question: What does the Anthropocene ‘meeting point’ highlight?

Answer 20

Answer: The Anthropocene serves as a ‘meeting point’ for physical geography, which measures biospheric changes, and human geography, which evaluates social and environmental inequalities linked to these changes.

Question 21

Six Planetary Boundaries Crossed

Question: What does crossing six planetary boundaries signify?

Answer 21

Answer: It signals that Earth’s capacity to sustain human and other life is severely threatened, with impacts like ocean acidification, biodiversity loss, and reduced climate predictability (Stockholm Resilience Centre, 2023).

Question 22

Stories of the Anthropocene

Question: What role do narratives play in understanding the Anthropocene?

Answer 22

answer: Narratives shape our understanding of the Anthropocene by framing human-environmental relations, offering insights into societal transformations, and guiding future actions (Power, 2017).

Question 23

Unequal Waste Management

Question: How does waste management differ between nations?

Answer 23

Answer: High-income nations effectively manage plastic waste, while low-to-middle-income countries often have inadequate systems, leading to environmental leakage (Ritchie, 2021).

Question 24

Human-Nature Interdependence

Question: How is human-nature interdependence evident in the Anthropocene?

Answer 24

Answer: Humans rely on nature for survival, yet often act as though independent. The Anthropocene highlights the vulnerability and resilience of nature under human impact