Half of Greenland's ice sheet disappeared during the last interglacial period, around 125,000 years ago. Sea levels rose 20 to 25 feet higher than today, not because of human activity, but because natural climate cycles had pushed the planet into one of its warmest phases in recent geological history. The ice melted so extensively that Greenland split into two separate ice domes with a broad corridor of exposed land running east to west across its midsection. This wasn't a minor fluctuation. This was a dramatic transformation of one of Earth's largest ice masses, and it happened without any industrial influence whatsoever. The evidence forces a question: if natural processes alone can drive changes this extreme, how do we separate natural variability from modern forcing in our current climate models? The geological record is unambiguous. Something else has always been going on here, and understanding that context is essential to making sense of where we are now.