♻️ Carbon cycle 3D
Carbon store
Atmosphere
≈ 875 GtC (CO₂ ≈ 420 ppm in 2023, up from ≈ 280 ppm before 1750)
The smallest of the big stores — which is why adding carbon to it changes the climate so quickly. CO₂ is measured continuously at Mauna Loa since 1958 (the Keeling curve).
Average per year, 2013–2022 (Global Carbon Budget 2023), in billions of tonnes of carbon (GtC):
- Emitted: fossil fuels & cement ≈ 9.6 + land-use change ≈ 1.3 = ≈ 10.9
- Stays in the air: ≈ 5.2 (about half)
- Taken up by land: ≈ 3.3
- Taken up by the ocean: ≈ 2.9
The numbers don’t add up exactly — the gap is the measurement uncertainty, which the researchers report openly.
1 GtC = 1 billion tonnes of carbon = 3.67 billion tonnes of CO₂.