Predictability of Earth’s long-term environmental transitions

Determine whether Earth’s long-term environmental transitions—including atmospheric oxygenation—are inherently predictable or probable within the externally allotted time for biological evolution, based on biogeochemical dynamics and feedbacks.

Background

The authors’ alternative to the hard-steps model requires that major environmental transitions be predictable outcomes of planetary–biogeochemical dynamics rather than rare events. They question whether this applies to Earth.

Establishing predictability would support the view that evolutionary milestones occurred when environmental windows opened, without invoking intrinsic improbability.

References

Whether this situation applies to the Earth is unknown, but a case for the inherent likelihood of environmental transitions (within the externally allotted time) can arguably be made once again using the GOE as an example.

— A reassessment of the "hard-steps" model for the evolution of intelligent life  (2408.10293 - Mills et al., 2024) in Section 'Planetary constraints and environmental trajectories'

Nonetheless, it is also clearly important to limit prediction to the predictable, though it is often not clear {\em a priori} whether this is possible!

— From trends to optimized forecasts: Quantifying the skill and advancing the utility of dynamics-based early warnings for tipping events  (2610.01677 - Plessis et al., 1 Oct 2026) in Section 7, “Concluding remarks”