Swimming in the Antarctic Ocean or sitting on the polar water front with only a t-shirt on was possible around 50 million years ago; this was a period of time in Earth's history known as the Eocene. The Antarctic real estate has since become far more frigid due to changes in levels of atmospheric carbon dioxide. Moreover, a study performed by academics at Yale University have found that at one point, temperature around the Antarctic region quite possibly hovered around 63 degrees Fahrenheit.
The study attributes oceanic factors or “heat transport” and “water formation” within the South Pacific Ocean as a significant cause for the temperatures believed to have occurred in the Antarctic. Science News states this was determined using the measurement of indicative isotopes in fossil shells. According to the Smithsonian Institution, a reason why water became warm during the Eocene epoch was the release of large amounts of methane trapped within the ocean floor. This warmer water is thought to have then heated the air around Antarctica.
Previous joint research by academics from Yale University and Syracuse University also supports the data indicating a warmer global temperature between 48 and 55 million years ago. Moreover, Syracuse University News cites an Associate Professor of Earth Sciences at the institution as saying the Earth was so warm during this period that there were crocodiles living in the arctic. These warm temperatures are indicated to have extended to both the polar regions per the 2011 research.
The belief that fossil records and ocean chemistry reveals data pointing to a warmer Antarctic during the Eocene epoch is also advocated by the Annenberg Foundation. Moreover, it is thought that carbon dioxide levels in the atmosphere were up to 10 times higher than today. Since carbon dioxide is a greenhouse gas, this reinforces the idea that much of globe including the Antarctic region was considerably warmer during the Eocene period.
The notions surrounding increased geological carbon emissions in the Eocene time are not all supportive as evident in climate modeling tested by the Max Planck Institute for Meteorology in Germany. Moreover, in exploring the ideas that sea-ice and thermodynamics models of water movement during the Eocene contributed to warmer oceanic waters, climate models are rejected as evidence due to simulation failure. Still, the publication does state that “paleo-reconstructions support the notion of ocean circulation switch at the onset of the Paleocene-Eocene Thermal Maximum or PETM”. In addition, it is also claimed that only a small amount of carbon was needed to help trigger the release of methane from ocean floor sediments.
Climatological research demonstrates that the world's climate is not constant. It also shows that changes in carbon dioxide levels have an influential effect on weather. During the Eocene period, it is believed some event on Earth triggered a rise in carbon dioxide released in to the environment, and that this rise in CO2 caused global temperatures to also increase. The strength of the data supporting this notion varies between studies, but considerable consensus exists around the idea of a warmer Eocene. Furthermore, the connection between water movement and above water temperatures is demonstrable enough to provide some reason to believe that warmer temperatures also existed in the Antarctic during the Eocene epoch.