Our concerns that global warming can be harmful to tropical forests may probably have to be reconsidered; as a matter of fact, roughly 60 million years ago forests thrived despite a considerably hostile climate.
A team of thirty researchers, coordinated by Carlos Saramillo of the Smithsonian Tropical Research Institute, came to this surprising conclusion. Their results were published in one of the recent issues of Science. The study highlights that at the time of transition between the Paleocene and the Eocene epochs - 56.3 million years ago - the earth's climate was characterized by an increase in temperature of 3-5 degrees and by an increase in the levels of atmospheric carbon dioxide two and half times greater than present levels (the epoch is called Paleocene-Eocene Thermal Maximum). Despite this , however, there was flourishing growth and proliferation of tropical forests.
By analyzing and comparing the pollen trapped in rocks found in Colombia and Venezuela, dating back to epochs before, during and after the Paleocene-Eocene Thermal Maximum , Jaramillo and his collaborators managed to establish that a remarkable and rapid development of the diversity of those forests took place, including many new species of trees. It appears the tropical forests benefited significantly even though it was a potentially hostile period.