Anthropocene and Planetary Boundaries

1. The Anthropocene: The Age of Humans

• Definition: The Anthropocene is the proposed current geological epoch, marking the period (roughly the last 200 years) where human activity has become the dominant influence on the climate and the environment.
• Origin of Term: Coined by Nobel Laureate Paul Crutzen. The prefix "Anthro-" signifies the decisive impact of humans.
• Core Idea: This framework represents a critical shift in thinking, recognizing that humanity has superseded natural forces as the primary agent of change on the planetary biosphere since the Industrial Revolution (c. 1800).

2. The Planetary Boundaries Framework

This framework offers a scientific method for measuring the impact of the Anthropocene.

• What is it? A framework that identifies nine critical Earth system processes which, together, regulate the stability and resilience of the planet. Each process has a "boundary" which, if crossed, could lead to abrupt and irreversible environmental changes.
• Developed By: A group of scientists led by Johan Rockström (Stockholm Resilience Center) and Will Steffen (Australian National University).
• Introduced: 2009.

Status of the Boundaries: A Worsening Trend

The number of transgressed boundaries has increased over time, indicating growing stress on Earth's systems.

• 2009: 3 out of 9 boundaries were crossed.
• 2015: 4 out of 9 boundaries were crossed.
• 2023: 6 out of 9 boundaries are now crossed.

3. Consequences and Urgency

Crossing these boundaries has real-world consequences, as highlighted by Johan Rockström.

• Climate Tipping Points: We have reached the warmest temperatures in the last 100,000 years.
• Immediate Costs (2023 data):
  • Human Cost: Up to 12,000 deaths directly attributed to climate change.
  • Economic Cost: An estimated $200 billion USD in damages.
• Future Projections: A "business as usual" scenario could lead to a catastrophic 18% loss of global GDP by 2050.

Exam Tip: You must be able to define both the Anthropocene and the Planetary Boundaries framework. Memorize the number of boundaries crossed by 2023 (six). The data on potential future GDP loss is a powerful statistic to use when explaining the urgency of the situation.