Humans could become the greatest driver of biosphere net gain in Earth history, but we are currently the second fastest driver of biosphere loss

While current human activity is driving the second-fastest rate of biosphere degradation in Earth's history, comparable to transient geological disruptors, humanity possesses the unique capacity to reflect on and transform its impact, potentially becoming the greatest driver of biosphere net gain and planetary habitability in Earth's history.

The Gist

Imagine Earth's history as a massive, 4.5-billion-year-old video game. For most of the game, the "players" (life forms) evolved slowly, and the "environment" (volcanoes, asteroids, climate shifts) changed at a glacial pace.

This paper argues that humans have just grabbed the controller and started playing at a speed no one has ever seen before. We are currently causing damage so fast and so deep that we are ranked as the second worst player in the game's history, right behind the giant asteroid that wiped out the dinosaurs.

However, the paper offers a twist: Humans are the only player in the game's history who can look at the screen, realize they are losing, and choose to change their strategy. We have the unique potential to become the greatest "good" player ever, turning the game around faster than nature ever could.

Here is the breakdown of their argument using simple analogies:

1. The Two Types of "Game Breakers"

The authors categorize everything that messes up the Earth's ecosystem into two buckets:

• The "Flash Crash" (Transient Disruptors):

  • What they are: Sudden, violent events like asteroid impacts or massive volcanic eruptions.
  • The Analogy: Imagine a tornado tearing through a forest. It destroys everything instantly. The forest is gone, the animals die, and the ecosystem is broken.
  • The Result: Nature eventually recovers, but it takes millions of years to rebuild the forest. During that time, the world is a "low-level" version of itself—less diverse, less productive, and simpler.
  • Where we fit: Currently, humans are acting like a tornado. We are cutting down forests, polluting oceans, and driving species extinct at a rate comparable to the worst disasters in Earth's history.

• The "System Upgrade" (Persistent Disruptors):

  • What they are: Slow, long-lasting changes that fundamentally improve how the planet works.
  • The Analogy: Imagine someone inventing electricity and wiring a whole city. It takes a long time to build the power plants and wires, but once it's done, the city runs better, brighter, and more efficiently than before.
  • Examples from history:
    • Oxygen: Tiny bacteria invented photosynthesis billions of years ago. It poisoned the early atmosphere (killing many early life forms), but eventually, it allowed complex animals (like us) to breathe and evolve.
    • Flowering Plants: When flowers evolved, they created a new, super-efficient way for plants and insects to work together, leading to a massive explosion of life.
  • The Result: These events make the planet more habitable, more diverse, and more productive over millions of years.

2. The Current Crisis: We Are the "Tornado"

Right now, humanity is acting like a Flash Crash.

• We have crossed the "safe limits" of the planet (like a car driving off the road).
• We are using up 30% of the planet's plant growth (food) for ourselves.
• We are causing species to go extinct 100 times faster than the natural background rate.
• The Verdict: If we keep going on our current path ("Business as Usual"), we will be the second most destructive force in Earth's history, only beaten by the dinosaur-killing asteroid.

3. The Hopeful Twist: We Can Be the "System Upgrade"

Here is the unique part of the paper: Humans are the only disruptor that can think.

A volcano doesn't know it's destroying a forest. An asteroid doesn't care about the dinosaurs. But we do. We can see the damage, understand the consequences, and choose to stop.

The authors suggest we can switch from being a "Tornado" to being a "System Upgrade" if we change how we live. They propose three ways to do this:

• Farming with Nature (The "Patchwork Quilt"): Instead of huge, single-crop farms that kill biodiversity, we can use "patchwork" farming. Think of it like a quilt where some squares are wild nature, some are crops, and they support each other. Indigenous peoples have done this for thousands of years (like using controlled burns to help forests grow back stronger).
• Sparing and Sharing (The "Library vs. The Park"): We need to be smarter about land.
  • Sparing: Use high-tech, efficient farming on small plots so we can leave huge areas of land completely wild for nature to recover.
  • Sharing: Design our cities and farms so that wild animals can live right alongside us (like birds in city parks or fish in sustainable oceans).
• The "New Normal" (The "Garden of the Future"): Nature is resilient. Even if we mess things up, new ecosystems will form. Some of these might be "novel ecosystems" with mixed species that have never existed before. Instead of fighting them, we can learn to manage them to be healthy and productive.

4. The Ultimate Goal: The "Green Road"

The paper concludes with a challenge. We have a choice between two paths:

1. The Rocky Road: We continue to destroy nature, causing a mass extinction. The Earth will eventually recover, but it will take millions of years, and we (or our descendants) might not be around to see it.
2. The Green Road: We use our intelligence to become "stewards." We actively repair the planet, restore biodiversity, and create a world that is better than the one we inherited.

The Bottom Line:
Humans are currently the second-worst thing to happen to Earth's life support system. But because we are the only ones who can choose to change, we have the potential to become the greatest force for good in Earth's history. We can fix the planet faster than nature ever could, but only if we decide to stop playing the game as a villain and start playing as a hero.

Technical Summary

1. Problem Statement

The paper addresses the critical question of how contemporary anthropogenic changes to the biosphere compare to major biotic shifts throughout Earth's geological history. While it is well-established that human activity is driving a mass extinction event (the "Sixth Extinction"), the authors argue that the current narrative focuses almost exclusively on degradation. They posit a gap in understanding: Can humanity transition from being a destructive force to a transformative agent that enhances planetary habitability?

The core problem is defining the trajectory of human impact relative to historical "disruptors." The authors seek to determine if humanity is destined to act as a transient disruptor (causing short-term, massive degradation followed by slow recovery) or if we have the unique capacity to become a persistent disruptor (driving sustained, long-term enhancement of biodiversity, biomass, and productivity).

2. Methodology

The authors employ a comparative historical analysis combining paleontological data with contemporary ecological metrics.

• Conceptual Framework: The study introduces the concept of "biosphere disruptors," agents that force global-scale macroevolutionary change. These are categorized into:
  • Transient Disruptors: Short-lived agents (mean duration $\approx 8.0 \times 10^5$ years) such as asteroid impacts and massive volcanism. These typically cause immediate biosphere degradation.
  • Persistent Disruptors: Long-lasting agents (mean duration $\approx 1.6 \times 10^8$ years) such as the evolution of oxygenic photosynthesis and land plants. These reconfigure the biosphere, often leading to sustained increases in habitability.
• Data Compilation: The authors analyzed 30 intervals of macroevolutionary change from the fossil record (Tables S1–S5).
  • Metrics Evaluated: Duration of impact, magnitude of change (percentage change in species/genus richness, biomass, and productivity), and rate of change.
  • Standardization: Extinction/origination rates were converted to a standard metric: Extinctions (or Originations) per Million Species Years (E/MSY or O/MSY) to allow direct comparison between deep-time events and modern anthropogenic rates.
• Comparative Scenarios: The study evaluates human impact under three scenarios:
  1. Current State: Recent past impacts.
  2. Business as Usual (BAU): Projected impacts by 2100 CE.
  3. Sustainable Stewardship: Potential impacts by 3100 CE if humanity acts as a persistent disruptor.
• Planetary Boundaries Context: The analysis is framed against the "Planetary Boundaries" framework, specifically the transgression of biosphere integrity (genetic and functional).

3. Key Contributions

• Reframing Human Agency: The paper challenges the deterministic view of humans as purely destructive. It argues that humanity is the first disrupting agent capable of self-reflection and conscious modification of its impact on planetary habitability.
• Quantitative Historical Benchmarking: By calculating rates of change (percentage change per duration), the authors provide a rigorous quantitative comparison showing that human-driven degradation is currently the second fastest in Earth's history, surpassed only by the Cretaceous-Palaeogene (K-Pg) bolide impact.
• The "Dual Potential" Hypothesis: The study posits that while humans are currently acting as a transient disruptor (degradation), we possess the unique potential to become the greatest driver of positive biosphere net gain in Earth history on centennial to millennial timescales.
• Identification of Pathways: The paper outlines three specific pathways for transitioning from transient to persistent disruption:
  1. Fostering diverse human-influenced ecologies (e.g., Indigenous fire management, agroforestry).
  2. Implementing "sparing and sharing" strategies for land and sea (e.g., intensification of agriculture to spare land, marine protected areas).
  3. Embracing novel ecologies and species associations (e.g., managing hybridization and non-native species integration).

4. Results

• Current Status (Transient Disruptor):
  • Humans are driving the second highest rate of biosphere degradation in Earth history (after the K-Pg impact).
  • Current rates of genetic diversity loss and functional integrity breach (HANPP >30%, extinction rates >100 E/MSY) exceed the "safe operating space" defined by planetary boundaries.
  • Anthropogenic deforestation and ocean deoxygenation are approaching the magnitude of the Permian-Triassic Mass Extinction (PTME).
• Historical Comparison:
  • Transient Disruptors (e.g., K-Pg, PTME) are associated with massive, temporary degradation, locking the biosphere into a state of "undesirable resilience" (low diversity/biomass) for millions of years before recovery.
  • Persistent Disruptors (e.g., Great Oxidation Event, Angiosperm Revolution) are associated with sustained increases in planetary habitability, biodiversity, and biomass over geological timescales.
• Future Projections:
  • If humanity follows a "Rocky Road" or "Highway" trajectory (SSP3/SSP5), we remain a transient disruptor, leading to locked-in low-biodiversity states.
  • If humanity follows a "Green Road" trajectory (SSP1) involving sustainable stewardship, we could drive the greatest rate of increase in planetary habitability in Earth history.
  • Unlike past disruptors, human-driven positive change could occur on decadal to millennial timescales, rather than millions of years.

5. Significance

• Paradigm Shift in Conservation: The paper moves beyond the "doom and gloom" narrative of the Anthropocene. It suggests that the geological record offers a blueprint for enhancement, not just survival. It argues that the goal should be to emulate the outcomes of past persistent disruptors (increased symbiosis, productivity, and diversity) rather than just avoiding the outcomes of transient ones.
• Policy and Governance Implications: The authors argue that achieving this transition requires a fundamental shift in international law and governance. Specifically, they call for a move from "freedom of the seas" and "common heritage" principles to a "responsibility for the seas" and a "common responsibility for the Earth System."
• Interdisciplinary Synthesis: The work bridges geology, paleontology, ecology, and social science, demonstrating that deep-time data is essential for understanding and navigating contemporary socio-ecological crises.
• Urgency and Agency: The conclusion emphasizes that while the risk of becoming a permanent transient disruptor (mass extinction) is high, the window for humanity to become a persistent enhancer of the biosphere is open but requires immediate, coordinated political and legal action.

In summary, the paper provides a rigorous geological and ecological argument that humanity stands at a unique evolutionary juncture: we are currently the second most destructive force in Earth's history, but we hold the unprecedented potential to become the most constructive force, provided we consciously shift from extraction to stewardship.