Most scientists believe that the early Earth’s climate was hot, with ocean temperatures reaching 80 degrees Celsius. However, a new study published on Feb. 26 in the journal Science Advances argues that Earth’s climatic conditions were actually much colder than assumed.

When the Earth’s first organisms formed 3.5 Ga (gigayears) or 3.5 billion years ago, both land and ocean were cold based on rock analysis conducted by a research team from the University of Bergen led by Harald Furnes. These rocks were volcanic rocks that were deposited at depths of two to four kilometres and sedimentary rocks that were originally mud that resembled clay, both of which are located in Greenstone Belt, South Africa.

Furnes, the university’s Professor Emeritus at the Department of Earth Science, in collaboration with Maarten de Wit, a professor from Nelson Mandela Metropolitan University in South Africa, explains that the rocks resembled the rocks from the ice age. Moreover, they found gypsum, which is produced under high pressure at very cold temperatures, proving that these rocks were exposed to cold water.

Most researchers believe that Earth's climatic conditions were hot at 3.5 Ga. New findings in South Africa create a new theory, presenting a much colder climate than previously suggested. Photo by Harald Furnes/University of Bergen

Most researchers believe that Earth’s climatic conditions were hot at 3.5 Ga. New findings in South Africa create a new theory, presenting a much colder climate than previously suggested. Photo by Harald Furnes/University of Bergen

Nevertheless, the research team believes that many may not give in to this claim and may even challenge the study. Still, Furnes thinks that this will encourage more research that will delve into early Earth to advance the knowledge that we have.

Many still believe that the early Earth was hot due to the amount of carbon dioxide at the time. Scientists assert that a partial pressure of 2.9 millibars of CO2 was just enough to keep the Earth from freezing.

This is not the first time that a study disputed the current theories about the early Earth. In fact, a recent study claimed that Earth was actually made from two planets.

A smaller planet called Theia fused with the Earth 4.5 billion years ago during a collision. Moreover, the event also caused a small piece to break off, which turned into the moon that we know of today.