By the time today’s preschoolers are babysitting their grandkids, global sea levels are likely to be pushing 2 feet higher than they are now and on the way to topping 8 feet above current levels by the year 2200, according to a new study.

The finding stems from geologic evidence that allowed scientists to tease apart a natural background pattern of how fast and how high sea levels rose as ice ages came and went over the past 2 million years.

Today’s pace of sea level rise is about twice as fast compared to historical standards, the team concluded. Going forward, seas will be pushed higher as rising temperatures force the great ice sheets in Greenland and Antarctica to disintegrate, glaciers around the world to retreat toward mountaintops, and warming ocean waters to expand, the study notes.