In a warm period 52 million years ago, tropical vegetation -- including palms trees -- thrived on the coast of Antarctica, researchers say. Drill cores of sediment obtained from the seafloor near Antarctica showed evidence of the intense ancient warming phase, researchers at Goethe University in Frankfurt, Germany, said. The findings highlight the extreme contrast between modern and past climatic conditions in Antarctica and the extent of global warmth during periods of elevated atmospheric carbon dioxide levels, a university release reported Wednesday. About 52 million years ago, the concentration of carbon dioxide in the atmosphere was more than twice as high as the greenhouse gas\' level today, researchers said. \"If the current CO2 emissions continue unabated due to the burning of fossil fuels, CO2 concentrations in the atmosphere, as they existed in the distant past, are likely to be achieved within a few hundred years,\" paleoclimatologist Jorg Pross said. \"By studying naturally occurring climate warming periods in the geological past, our knowledge of the mechanisms and processes in the climate system increases. This contributes enormously to improving our understanding of current human-induced global warming.\" The findings also support computer models that indicate future climate warming will be particularly pronounced in high-latitude regions near the poles, the researchers said.