6 Million Cubic Miles of Ice Melted in a Few Thousand Years

Start with a single cubic mile of ice and convert it instantaneously to water. The flood that produces would be enormous by any human standard. Now multiply that by six million - the estimated volume of glacial ice sitting on the continental landmasses of North America and Eurasia at the peak of the last Ice Age. All of it is gone now. The question Randall Carlson forces is deceptively simple: how fast did it go?

If that volume of ice melted gradually over 50,000 or 100,000 years, the resulting sea level rise and meltwater discharge would be spread thinly enough across time to look almost imperceptible in any given century. But if the same six million cubic miles of ice melted over three, four, or five thousand years - as the evidence increasingly suggests - the implications are categorically different. The meltwater pulses, the catastrophic floods, the rapid sea level rises recorded in the geological record all point toward a process that was far faster and far more violent than the gradualist model has ever been comfortable acknowledging. The ice did not gently fade. It collapsed.

Join Randall in the field in New York State for his Finger Lakes Tour, Aug 30 Sep 5, 2026