Etched into ceilings of the mine shafts is the largest intact fossilforest ever seen—at least four square miles of tropical wilderness preserved 307 million years ago.
The jury is still out, though fossil charcoal shows that forest fires were common at the time.
答案依然悬而未决，尽管木炭的化石表明森林大火在那时是很普遍的。
3
Tropical forest trees are absorbing about 18% of the carbon dioxide added to the atmosphere each year from burning fossil fuels, substantially buffering the rate of change.