ANTARCTICA was the only continent where extensive coal beds failed to form
during the warm Cretaceous period between 150 and 65 million years ago. The lack
of coal has long been a puzzle because the continent was heavily forested at the
time. Now David Beerling of the University of Sheffield has developed a model
that solves the puzzle (Geophysical Research Letters, vol 27, p
253).
He says high levels of carbon dioxide stimulated the growth of thick forest
canopies, causing the water table to drop. “Because the vegetation was actively
transpiring, it maintained the water balance close to zero…
