⚖️ Carbon is conserved — it moves between reservoirs but the total amount on Earth never changes. The stacked chart makes this visible.
🔥 Fossil fuels transfer ancient carbon to the atmosphere — burning releases carbon locked underground for millions of years, increasing atmospheric CO₂ beyond what natural sinks can absorb quickly.
🌊 The ocean is the largest sink but has finite capacity — as the ocean absorbs more CO₂, its equilibrium shifts upward and absorption slows. It also causes ocean acidification.
📈 The system finds a new, higher equilibrium — even after fossil fuels are depleted, atmospheric CO₂ does not return to pre-industrial levels. The extra carbon is permanently redistributed.