The cold of the south pole is not eternal

1991/04/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Klima

M

in the heart of the Ego pole fossils formed by the leaves of a tree have been found. This tree belonged to the species Nothofagus. With this discovery we must give the reason to those who already pointed out that the south pole was not so cold three million years ago.

University of Nebraska researcher David Harwood has collected more than 50 kg of these fossils. This tree is a kind of beech and can give the idea of the environment of yesteryear. The evolution of this species is very slow and could not adapt to the climate change that occurred in the south pole.

Today, these trees are found in South America, so their ecosystem is known.

The collected fossils are in very good condition. It seems that the leaves of this type of beech fell very quickly in autumn forming a niche next to the tree.

It can be extracted from the veins and pores of the studied leaves, so there is also trace of the fungi. Of these, it is possible to estimate the humidity, temperature, photosynthesis and carbon dioxide levels of the time.

Therefore, although it is to advance the data, the temperature in the south pole stood at 5ºC in summer, 15ºC more than today. The winter temperature estimate is -20ºC.