Over the past three million years, the Earth has periodically plunged into an ice age. Although the planet is now in an inter-glacial period, the situation can change due to increased global temperatures, scientists say.

Scientists at Cardiff University have found that melting Antarctic icebergs could trigger a chain reaction that plunges the Earth into a new ice age, The Daily Mail reported.

As part of the research, the scientists studied rock fragments dropped in the ocean by melting icebergs and found out that they lead to changes in deep ocean circulation.

The melting of Antarctic icebergs shifts a huge amount of fresh water from the Southern Ocean into the Atlantic. Thus, the Southern Ocean becomes saltier and the North Atlantic gets fresher, which leads to a change of the ocean circulation pattern.

With such changes, carbon dioxide is pulled away from the atmosphere more quickly, reducing the so-called greenhouse effect and thus pushing the Earth into the new ice age.

"Such a leading role for the Southern Ocean and Antarctica in global climate has been speculated but seeing it so clearly in geological evidence was very exciting," Aidan Starr, from the School of Earth and Environmental Sciences at Cardiff University, said.

However, according to the scientists, the current increase in global temperatures may disrupt the ordinary ice age cycle because the Southern Ocean is likely to become warmer and prevent icebergs from travelling far enough to change ocean circulation patterns in a way that triggers an ice age.