Marsha Gonzales age 12, of Auabach, Germany,for her question:

Have we proof that Antarctica was once warm?

The coldest place on earth is Antarctica, the frozen ice cap which sits upon the globe’s South pole. Some of the massive glaciers are a mile, some two miles and some three miles thick and in some places their gigantic weight has pressed down the land to below sea level. But the layers of rocks below the ice tell us that this frigid region once enjoyed a temperate climate.
Captain Robert Scott led a team of explorers into the frigid Antartica in 1901 and brought back a sample of coal bearing rock. This amazing item remained a mystery until the world's ice box was given a more thorough examination during the IGY. Many more coal deposits have been found, some of them 13 feet thick.
The rocky layers of the earth’s crust are like the pages of a diary and some of them date back more than 2,000 million years. Geologists can read these rocky pages and tell how they were formed. Specimens of fossil plants and animals are pressed between the diary pages, Science can date them and tall how far back in the past they lived.
Here and there, mountain ridges and ragged cliffs poke layers of bare rock above the white wilderness of Antarctic. In a few places, this rock strata has bean probed and scientists have turned back the diary pages 1,500 million years. The long story tells of mountains rising and falling, of seas flooding the land, of periods of volcanic activity and, finally, the coming of the icy climate which covered the south. polar area with its massive glaciers.
In rocks formed 350 million years ago there are fossil brachipods and other simple animals and plants. These life forma have bean found in rocks of this age over most of the earth.
But in Antarctica, the simple beginnings of life ware delayed by a long Ice Age. In the rest of the world, life continued to develop and the Age of Reptiles came and went.
Finally the icy grip was lifted from Antarctica and plant life began to thrive. They left their fossil remains in the rocky pages formed 200 to 250 million years ago. Fossil leaves twelve inches long, seeds, pollen and petrified trees have been found. These fossils and the layers of black coal tell us that Antarctica was once lush with rich forests   and these plants could have thrived only in a gentle and temperate climate.
The process of life in Antarctica was halted again about a million years ago. The Ice Ages which came to the northern regions formed the massive glaciers which still form the south polar ice cap. Most of the diary of Antarctica is buried under a mile or more of ice and still unexplored. So far, we have only a sketchy story taken from a few outcropping of bare rook. But the fossil plants and the coal prove that the south pole was not always cold, Some 250 million years ago it was warm enough to support forests.