The amount of sea ice in Antarctica has stayed broadly the same over the past 100 years, scientists have found - contrasting sharply with declining levels in the Arctic.
- Video report by ITV News correspondent Duncan Golestani:
The harsh, unforgiving climate of the south pole has made Antarctic ice patterns much more difficult to explain than its northern cousin.
Scientists have now turned to the history books for a deeper understanding.
The records of pioneering explorers such as Captain Scott and Ernest Shackleton have helped build a clear picture of the environment as it was a century ago, using their logs to estimate the amount of sea ice at that time.
Painstakingly, researchers have used accounts of when and where the explorers noted being in the ice, and compared it to modern day readings.
While the levels have ebbed and flowed over the years, generally speaking, the figures suggest not much has changed.
Julienne Stroeve, from the US National Snow and Ice Data Centre, said the hole in the ozone layer might be helping.