The concept you're referring to revolves around the idea of "Planetary Boundaries," a framework proposed by a group of Earth system and environmental scientists led by Johan Rockström and Will Steffen. These boundaries define the safe operating space for humanity concerning the Earth’s vital biophysical systems. Crossing these boundaries increases the Risk of large-scale environmental changes that could be catastrophic. chatgpt 
Here are the **non-negotiable planetary preconditions** or **boundaries** that humanity needs to respect:
1. **Climate Change**:
- The concentration of carbon dioxide (CO₂) in the atmosphere must stay below 350 parts per million (ppm) to maintain a stable climate. Exceeding this boundary leads to significant changes in the climate system, increasing the risk of extreme weather events, sea-level rise, and disruption of ecosystems.
2. **Biosphere Integrity (Biodiversity Loss)**:
- Species extinction rates should not exceed 10 extinctions per million species per year. High biodiversity is crucial for ecosystem resilience, which supports human life through services like pollination, water purification, and disease regulation.
3. **Biogeochemical Flows (Nitrogen and Phosphorus Cycles)**:
- The nitrogen boundary is set at 62 million tons per year, and phosphorus should not exceed 11 million tons per year. Excessive nitrogen and phosphorus from fertilizers and other sources can lead to eutrophication, dead zones in oceans, and loss of biodiversity.
4. **Land-System Change**:
- No more than 15% of the ice-free land surface should be converted for agricultural or urban use. Excessive land-use change disrupts ecosystems, reduces biodiversity, and affects the global carbon and water cycles.
5. **Freshwater Use**:
- Global human consumption of freshwater should not exceed 4,000 cubic kilometers per year. Overuse can lead to water scarcity, affecting agriculture, health, and ecosystems.
6. **Ocean Acidification**:
- The average global surface ocean pH should not decline by more than 0.1 units from the pre-industrial level. Increased acidity threatens marine life, particularly organisms that rely on calcium carbonate, like corals and shellfish.
7. **Atmospheric Aerosol Loading**:
- While no global boundary has been quantified, regional thresholds exist for aerosol concentrations (tiny particles in the atmosphere). Excessive aerosols affect climate, health, and monsoon patterns.
8. **Stratospheric Ozone Depletion**:
- The concentration of ozone in the stratosphere should remain above 276 Dobson Units. Depletion increases UV radiation, raising risks of skin cancer and damaging ecosystems.
9. **Introduction of Novel Entities (Chemical Pollution and Plastic Waste)**:
- While not yet fully quantified, this boundary addresses the impact of synthetic chemicals, radioactive materials, microplastics, and other novel substances that can disrupt biological and ecological systems.
These planetary boundaries represent the non-negotiable preconditions for sustaining human life on Earth. Staying within them is essential to avoid deleterious or even catastrophic environmental changes at continental to global scales. chatgpt