Carbon moves in a loop — out of volcanoes and breath, back into plants and oceans — and for ages it balanced. Burning fossil fuels adds carbon faster than the loop removes it, thickening the atmosphere's heat-trapping blanket.
Carbon in constant motion
Carbon cycles among the atmosphere, oceans, living things, and rocks. Photosynthesis pulls CO₂ out of the air; respiration and decomposition return it; oceans absorb and release it. Over millions of years, some carbon is locked away as fossil fuels. Burning those fuels releases that stored carbon rapidly, raising atmospheric CO₂.
CO₂ and other greenhouse gases let sunlight in but trap outgoing heat, warming the planet. More CO₂ means more trapped heat — the core mechanism of human-caused climate change.
Atmospheric CO₂ has risen from about 280 ppm before industrialization to over 420 ppm today, tracking fossil-fuel emissions.
- Coal formed from plants that removed CO₂ from the air long ago.
- Consider what happens to that carbon when the coal is burned.
- Explain the effect on atmospheric CO₂ and climate.
What you should see: Burning coal returns long-buried carbon to the atmosphere as CO₂, raising its concentration and strengthening the greenhouse effect.