The concept of “planetary boundaries” has become one of the most influential frameworks in modern environmental science—shaping global policy, corporate behavior, and public perception. But how solid is it, really?

In this episode of Sanity Check, Dr. David R. Legates examines the origins of the planetary boundaries model and walks through each of its ten proposed limits—from climate change and biodiversity loss to ocean chemistry and chemical pollution. Along the way, he raises critical questions about the scientific ambiguity behind so-called “tipping points,” the arbitrariness of defined thresholds, and the growing tendency to treat uncertain models as settled fact.

Are we truly approaching environmental collapse—or are we being guided by a framework that overstates risk and underestimates resilience?

This episode challenges one of the dominant narratives in environmental discourse and asks whether these “guardrails” are grounded in reality—or constructed to drive a predetermined conclusion.

Links:

https://www.science.org/doi/10.1126/sciadv.adh2458

https://www.popularmechanics.com/science/environment/a45124009/humanity-oversteps-planetary-boundaries/

https://www.popularmechanics.com/science/environment/a70381572/aquatic-deoxygenation-planetary-boundaries-climate-crisis/

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