Environment

For decades, scientists believed the Arctic Ocean was sealed under a massive slab of ice during the coldest ice ages — but new research proves otherwise. Sediment samples from the seafloor, paired with cutting-edge climate simulations, show that the Arctic actually remained partially open, with seasonal sea ice allowing life to survive in the harshest climates. Traces of ancient algae, thriving only when light and water mix, reveal that the region was never a frozen tomb. This discovery not only reshapes our understanding of Earth’s past but offers vital clues about how the Arctic — and our planet — may respond to climate extremes ahead.