SEA LEVEL RISES Over the past 100,000 years, Earth’s sea levels have risen and fallen naturally with the advance and retreat of massive ice sheets. These shifts, driven by glacial cycles, often spanned tens of meters. What makes today’s rise stand out is the speed. Modern sea level changes are happening much faster than most natural cycles in the geologic record. Studying both long-term patterns and present-day trends helps us understand the balance between natural processes and human influence