Researchers have long tried to figure out what happened about a million years ago when a major shift occurred in Earth’s climate system, resulting ice sheets. Recently, scientists extracted and analyzed cores of deep-sea sediments taken in the south and north Atlantic to discover that the soil patterns from previous ice ages allowed ice sheets to grow thicker and more stable shaping the global climate as we know it today. This research “highlights the importance of the North Atlantic region and ocean circulation for present and future climate change.”