evidence: There’s little sign that the melting of the ice caps will slow any time soon. If anything, it’s going to get exponentially faster, scientists say. Like the glaciers themselves, it’s a process that begins slowly but carries with it a terrifying momentum. The ice caps store 99 percent of all the freshwater on Earth. It is a staggering amount of water, and the significance is readily apparent if you’ve ever stood on the shore of one of North America’s Great Lakes and gazed outward to the watery horizon. All that water, enough that it appears to be an inland sea, is but a fraction of what’s carried within the solid bulk of Antarctica. [...] So, while the ice caps aren’t going to disappear, that’s largely beside the point. There’s so much water locked in ice on Earth that releasing even a small portion of it can cause big changes. We need only look back in time to see what we might be in for. During the last interglacial period, a bit over 100,000 years ago, global temperatures were around 3 degrees hotter than today. That’s about as warm as the planet is projected to be in 2100, if we’re lucky. Despite that relatively small change in temperature, sea levels may have been 10 feet higher than they are today. Is it a glimpse of our future? Only time will tell.