The U.S. Geological Survey (USGS) has warned that the Arctic could face seasonally ice-free conditions and much warmer temperatures in the future which may lead to intensified storms and increased winter precipitation.

The USGS scientists have found evidence that the Arctic Ocean and Nordic Seas were too warm to support summer sea ice during the mid-Pliocene period, over three million years ago, when temperatures were similar to those projected for the end of this century.

They said the warm period is also used as an analogy to understand future conditions.

“In looking back 3 million years, we see a very different pattern of heat distribution than today with much warmer waters in the high latitudes,” said USGS scientist Marci Robinson.

Robinson said: “The lack of summer sea ice during the mid-Pliocene suggests that the record-setting melting of Arctic sea ice over the past few years could be an early warning of more significant changes to come.”

Loss of sea ice could have varied and extensive consequences, such as contributions to continued Arctic warming, accelerated coastal erosion due to increased wave activity, impacts to large predators like polar bears and seals that depend on sea ice cover, the USGS Website said.

The U.S. body found that summer sea-surface temperatures in the Arctic were between 10°C to 18°C during the mid-Pliocene, while current temperatures are around or below 0°C.

Examining past climate conditions allows for a true understanding of how earth’s climate system really functions.

USGS research on the mid-Pliocene is the most comprehensive global reconstruction for any warm period. This will help refine climate models, which currently underestimate the rate of sea ice loss in the Arctic.

Global average surface temperatures during the mid-Pliocene were about 3°C greater than today and within the range projected for the 21st century by the Intergovernmental Panel on Climate Change.

Scientists studied conditions during the mid-Pliocene by analysing fossils dated back to this time period.

It could also intensify mid-latitude storm tracks and increase winter precipitation in western and southern Europe, and less rainfall in the American west.