The coal forests
Vast swamp forests become the coal we burn today
See it on the timeline →In depth
The combination of vast tropical swamps and slow decay produced an unmatched burial of organic carbon. One explanation is that fungi had not yet evolved efficient enzymes for breaking down lignin. That carbon burial drew down so much CO₂ that atmospheric oxygen reached roughly 35 per cent — hence the giant insects — and the climate cooled into a long ice age. Industrial Europe and America were built on precisely these coal seams.
For children
Earth was covered in giant swamp forests with trees as tall as houses, and dragonflies the size of seagulls. When the trees fell they did not rot properly but were pressed down into the ground. Millions of years later they became coal — which humans later dug up and burned.
Connects to
Part of Terra Saga — the story of Earth on a timeline. terrasaga.org