The team analyzed sediment cores taken from the deep seafloor of the North Atlantic Ocean. The cores contain a record of Earth's climate over the past several million years, including evidence of glacial cycles.
By studying the sediment cores, the researchers found that the gradual intensification of glacial cycles began about a million years ago. This intensification was marked by an increase in the amplitude and frequency of glacial cycles.
The researchers also found that the intensification of glacial cycles was linked to changes in the Earth's orbit. Specifically, they found that the Earth's orbit became more elliptical and its axis of rotation shifted slightly. These changes caused changes in the amount of sunlight that reached the Earth's surface, which in turn affected the growth and melting of ice sheets.
In addition, the researchers found that changes in the Earth's orbit caused the ice sheets to become more sensitive to changes in climate. This means that even small changes in climate could cause the ice sheets to grow or melt rapidly, leading to more intense glacial cycles.
The team's findings are important because they provide new insights into the causes of glacial cycles and their role in Earth's climate system. This knowledge can help scientists better predict how the Earth's climate will change in the future.
The study was published in the journal Science Advances.
